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Merge branch 'sched/core' into core/locking, to prepare the kernel/locking/ file move

Browse Source 
Conflicts:
	kernel/Makefile

There are conflicts in kernel/Makefile due to file moving in the
scheduler tree - resolve them.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2013-11-06 07:50:37 +01:00
commit c90423d1de
113 changed files with 3506 additions and 1573 deletions
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76
Documentation/sysctl/kernel.txt
View File

@ -355,6 +355,82 @@ utilize.
==============================================================
numa_balancing
Enables/disables automatic page fault based NUMA memory
balancing. Memory is moved automatically to nodes
that access it often.
Enables/disables automatic NUMA memory balancing. On NUMA machines, there
is a performance penalty if remote memory is accessed by a CPU. When this
feature is enabled the kernel samples what task thread is accessing memory
by periodically unmapping pages and later trapping a page fault. At the
time of the page fault, it is determined if the data being accessed should
be migrated to a local memory node.
The unmapping of pages and trapping faults incur additional overhead that
ideally is offset by improved memory locality but there is no universal
guarantee. If the target workload is already bound to NUMA nodes then this
feature should be disabled. Otherwise, if the system overhead from the
feature is too high then the rate the kernel samples for NUMA hinting
faults may be controlled by the numa_balancing_scan_period_min_ms,
numa_balancing_scan_delay_ms, numa_balancing_scan_period_max_ms,
numa_balancing_scan_size_mb, numa_balancing_settle_count sysctls and
numa_balancing_migrate_deferred.
==============================================================
numa_balancing_scan_period_min_ms, numa_balancing_scan_delay_ms,
numa_balancing_scan_period_max_ms, numa_balancing_scan_size_mb
Automatic NUMA balancing scans tasks address space and unmaps pages to
detect if pages are properly placed or if the data should be migrated to a
memory node local to where the task is running. Every "scan delay" the task
scans the next "scan size" number of pages in its address space. When the
end of the address space is reached the scanner restarts from the beginning.
In combination, the "scan delay" and "scan size" determine the scan rate.
When "scan delay" decreases, the scan rate increases. The scan delay and
hence the scan rate of every task is adaptive and depends on historical
behaviour. If pages are properly placed then the scan delay increases,
otherwise the scan delay decreases. The "scan size" is not adaptive but
the higher the "scan size", the higher the scan rate.
Higher scan rates incur higher system overhead as page faults must be
trapped and potentially data must be migrated. However, the higher the scan
rate, the more quickly a tasks memory is migrated to a local node if the
workload pattern changes and minimises performance impact due to remote
memory accesses. These sysctls control the thresholds for scan delays and
the number of pages scanned.
numa_balancing_scan_period_min_ms is the minimum time in milliseconds to
scan a tasks virtual memory. It effectively controls the maximum scanning
rate for each task.
numa_balancing_scan_delay_ms is the starting "scan delay" used for a task
when it initially forks.
numa_balancing_scan_period_max_ms is the maximum time in milliseconds to
scan a tasks virtual memory. It effectively controls the minimum scanning
rate for each task.
numa_balancing_scan_size_mb is how many megabytes worth of pages are
scanned for a given scan.
numa_balancing_settle_count is how many scan periods must complete before
the schedule balancer stops pushing the task towards a preferred node. This
gives the scheduler a chance to place the task on an alternative node if the
preferred node is overloaded.
numa_balancing_migrate_deferred is how many page migrations get skipped
unconditionally, after a page migration is skipped because a page is shared
with other tasks. This reduces page migration overhead, and determines
how much stronger the "move task near its memory" policy scheduler becomes,
versus the "move memory near its task" memory management policy, for workloads
with shared memory.
==============================================================
osrelease, ostype & version:
# cat osrelease

2
MAINTAINERS
View File

@ -7304,6 +7304,8 @@ S: Maintained
F: kernel/sched/
F: include/linux/sched.h
F: include/uapi/linux/sched.h
F: kernel/wait.c
F: include/linux/wait.h
SCORE ARCHITECTURE
M: Chen Liqin <liqin.linux@gmail.com>

1
arch/alpha/include/asm/Kbuild
View File

@ -3,3 +3,4 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/arc/include/asm/Kbuild
View File

@ -46,3 +46,4 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

1
arch/arm/include/asm/Kbuild
View File

@ -32,3 +32,4 @@ generic-y += termios.h
generic-y += timex.h
generic-y += trace_clock.h
generic-y += unaligned.h
generic-y += preempt.h

1
arch/arm64/include/asm/Kbuild
View File

@ -50,3 +50,4 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

1
arch/avr32/include/asm/Kbuild
View File

@ -7,6 +7,7 @@ generic-y += div64.h
generic-y += emergency-restart.h
generic-y += exec.h
generic-y += futex.h
generic-y += preempt.h
generic-y += irq_regs.h
generic-y += param.h
generic-y += local.h

1
arch/blackfin/include/asm/Kbuild
View File

@ -44,3 +44,4 @@ generic-y += ucontext.h
generic-y += unaligned.h
generic-y += user.h
generic-y += xor.h
generic-y += preempt.h

1
arch/c6x/include/asm/Kbuild
View File

@ -56,3 +56,4 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

1
arch/cris/include/asm/Kbuild
View File

@ -11,3 +11,4 @@ generic-y += module.h
generic-y += trace_clock.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

1
arch/frv/include/asm/Kbuild
View File

@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/h8300/include/asm/Kbuild
View File

@ -6,3 +6,4 @@ generic-y += mmu.h
generic-y += module.h
generic-y += trace_clock.h
generic-y += xor.h
generic-y += preempt.h

1
arch/hexagon/include/asm/Kbuild
View File

@ -53,3 +53,4 @@ generic-y += types.h
generic-y += ucontext.h
generic-y += unaligned.h
generic-y += xor.h
generic-y += preempt.h

1
arch/ia64/include/asm/Kbuild
View File

@ -3,4 +3,5 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += kvm_para.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += vtime.h

1
arch/m32r/include/asm/Kbuild
View File

@ -3,3 +3,4 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/m68k/include/asm/Kbuild
View File

@ -31,3 +31,4 @@ generic-y += trace_clock.h
generic-y += types.h
generic-y += word-at-a-time.h
generic-y += xor.h
generic-y += preempt.h

1
arch/metag/include/asm/Kbuild
View File

@ -52,3 +52,4 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

2
arch/metag/include/asm/topology.h
View File

@ -26,6 +26,8 @@
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#define cpu_to_node(cpu) ((void)(cpu), 0)

1
arch/microblaze/include/asm/Kbuild
View File

@ -3,3 +3,4 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += syscalls.h
generic-y += preempt.h

1
arch/mips/include/asm/Kbuild
View File

@ -11,5 +11,6 @@ generic-y += sections.h
generic-y += segment.h
generic-y += serial.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += ucontext.h
generic-y += xor.h

19
arch/mips/kernel/rtlx.c
View File

@ -172,8 +172,9 @@ int rtlx_open(int index, int can_sleep)
if (rtlx == NULL) {
if( (p = vpe_get_shared(tclimit)) == NULL) {
if (can_sleep) {
__wait_event_interruptible(channel_wqs[index].lx_queue,
(p = vpe_get_shared(tclimit)), ret);
ret = __wait_event_interruptible(
channel_wqs[index].lx_queue,
(p = vpe_get_shared(tclimit)));
if (ret)
goto out_fail;
} else {
@ -263,11 +264,10 @@ unsigned int rtlx_read_poll(int index, int can_sleep)
/* data available to read? */
if (chan->lx_read == chan->lx_write) {
if (can_sleep) {
int ret = 0;
__wait_event_interruptible(channel_wqs[index].lx_queue,
int ret = __wait_event_interruptible(
channel_wqs[index].lx_queue,
(chan->lx_read != chan->lx_write) ||
sp_stopping, ret);
sp_stopping);
if (ret)
return ret;
@ -440,14 +440,13 @@ static ssize_t file_write(struct file *file, const char __user * buffer,
/* any space left... */
if (!rtlx_write_poll(minor)) {
int ret = 0;
int ret;
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
__wait_event_interruptible(channel_wqs[minor].rt_queue,
rtlx_write_poll(minor),
ret);
ret = __wait_event_interruptible(channel_wqs[minor].rt_queue,
rtlx_write_poll(minor));
if (ret)
return ret;
}

5
arch/mips/mm/init.c
View File

@ -124,7 +124,7 @@ void *kmap_coherent(struct page *page, unsigned long addr)
BUG_ON(Page_dcache_dirty(page));
inc_preempt_count();
pagefault_disable();
idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
#ifdef CONFIG_MIPS_MT_SMTC
idx += FIX_N_COLOURS * smp_processor_id() +
@ -193,8 +193,7 @@ void kunmap_coherent(void)
write_c0_entryhi(old_ctx);
EXIT_CRITICAL(flags);
#endif
dec_preempt_count();
preempt_check_resched();
pagefault_enable();
}
void copy_user_highpage(struct page *to, struct page *from,

1
arch/mn10300/include/asm/Kbuild
View File

@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/openrisc/include/asm/Kbuild
View File

@ -67,3 +67,4 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += word-at-a-time.h
generic-y += xor.h
generic-y += preempt.h

1
arch/parisc/include/asm/Kbuild
View File

@ -4,3 +4,4 @@ generic-y += word-at-a-time.h auxvec.h user.h cputime.h emergency-restart.h \
div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \
poll.h xor.h clkdev.h exec.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/powerpc/include/asm/Kbuild
View File

@ -2,4 +2,5 @@
generic-y += clkdev.h
generic-y += rwsem.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += vtime.h

1
arch/s390/include/asm/Kbuild
View File

@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/score/include/asm/Kbuild
View File

@ -4,3 +4,4 @@ header-y +=
generic-y += clkdev.h
generic-y += trace_clock.h
generic-y += xor.h
generic-y += preempt.h

1
arch/sh/include/asm/Kbuild
View File

@ -34,3 +34,4 @@ generic-y += termios.h
generic-y += trace_clock.h
generic-y += ucontext.h
generic-y += xor.h
generic-y += preempt.h

1
arch/sparc/include/asm/Kbuild
View File

@ -16,3 +16,4 @@ generic-y += serial.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += word-at-a-time.h
generic-y += preempt.h

1
arch/tile/include/asm/Kbuild
View File

@ -38,3 +38,4 @@ generic-y += termios.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += xor.h
generic-y += preempt.h

1
arch/um/include/asm/Kbuild
View File

@ -3,3 +3,4 @@ generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h
generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h
generic-y += switch_to.h clkdev.h
generic-y += trace_clock.h
generic-y += preempt.h

1
arch/unicore32/include/asm/Kbuild
View File

@ -60,3 +60,4 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

29
arch/x86/include/asm/atomic.h
View File

@ -6,6 +6,7 @@
#include <asm/processor.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>
#include <asm/rmwcc.h>
/*
* Atomic operations that C can't guarantee us. Useful for
@ -76,12 +77,7 @@ static inline void atomic_sub(int i, atomic_t *v)
*/
static inline int atomic_sub_and_test(int i, atomic_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
: "+m" (v->counter), "=qm" (c)
: "ir" (i) : "memory");
return c;
GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, i, "%0", "e");
}
/**
@ -118,12 +114,7 @@ static inline void atomic_dec(atomic_t *v)
*/
static inline int atomic_dec_and_test(atomic_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "decl %0; sete %1"
: "+m" (v->counter), "=qm" (c)
: : "memory");
return c != 0;
GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e");
}
/**
@ -136,12 +127,7 @@ static inline int atomic_dec_and_test(atomic_t *v)
*/
static inline int atomic_inc_and_test(atomic_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "incl %0; sete %1"
: "+m" (v->counter), "=qm" (c)
: : "memory");
return c != 0;
GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e");
}
/**
@ -155,12 +141,7 @@ static inline int atomic_inc_and_test(atomic_t *v)
*/
static inline int atomic_add_negative(int i, atomic_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
: "+m" (v->counter), "=qm" (c)
: "ir" (i) : "memory");
return c;
GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, i, "%0", "s");
}
/**

28
arch/x86/include/asm/atomic64_64.h
View File

@ -72,12 +72,7 @@ static inline void atomic64_sub(long i, atomic64_t *v)
*/
static inline int atomic64_sub_and_test(long i, atomic64_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "subq %2,%0; sete %1"
: "=m" (v->counter), "=qm" (c)
: "er" (i), "m" (v->counter) : "memory");
return c;
GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, i, "%0", "e");
}
/**
@ -116,12 +111,7 @@ static inline void atomic64_dec(atomic64_t *v)
*/
static inline int atomic64_dec_and_test(atomic64_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "decq %0; sete %1"
: "=m" (v->counter), "=qm" (c)
: "m" (v->counter) : "memory");
return c != 0;
GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", "e");
}
/**
@ -134,12 +124,7 @@ static inline int atomic64_dec_and_test(atomic64_t *v)
*/
static inline int atomic64_inc_and_test(atomic64_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "incq %0; sete %1"
: "=m" (v->counter), "=qm" (c)
: "m" (v->counter) : "memory");
return c != 0;
GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", "e");
}
/**
@ -153,12 +138,7 @@ static inline int atomic64_inc_and_test(atomic64_t *v)
*/
static inline int atomic64_add_negative(long i, atomic64_t *v)
{
unsigned char c;
asm volatile(LOCK_PREFIX "addq %2,%0; sets %1"
: "=m" (v->counter), "=qm" (c)
: "er" (i), "m" (v->counter) : "memory");
return c;
GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, i, "%0", "s");
}
/**

24
arch/x86/include/asm/bitops.h
View File

@ -14,6 +14,7 @@
#include <linux/compiler.h>
#include <asm/alternative.h>
#include <asm/rmwcc.h>
#if BITS_PER_LONG == 32
# define _BITOPS_LONG_SHIFT 5
@ -204,12 +205,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr)
*/
static inline int test_and_set_bit(long nr, volatile unsigned long *addr)
{
int oldbit;
asm volatile(LOCK_PREFIX "bts %2,%1\n\t"
"sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
return oldbit;
GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, nr, "%0", "c");
}
/**
@ -255,13 +251,7 @@ static inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
*/
static inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
{
int oldbit;
asm volatile(LOCK_PREFIX "btr %2,%1\n\t"
"sbb %0,%0"
: "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
return oldbit;
GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, nr, "%0", "c");
}
/**
@ -314,13 +304,7 @@ static inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
*/
static inline int test_and_change_bit(long nr, volatile unsigned long *addr)
{
int oldbit;
asm volatile(LOCK_PREFIX "btc %2,%1\n\t"
"sbb %0,%0"
: "=r" (oldbit), ADDR : "Ir" (nr) : "memory");
return oldbit;
GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, nr, "%0", "c");
}
static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)

50
arch/x86/include/asm/calling.h
View File

@ -48,6 +48,8 @@ For 32-bit we have the following conventions - kernel is built with
#include <asm/dwarf2.h>
#ifdef CONFIG_X86_64
/*
* 64-bit system call stack frame layout defines and helpers,
* for assembly code:
@ -192,3 +194,51 @@ For 32-bit we have the following conventions - kernel is built with
.macro icebp
.byte 0xf1
.endm
#else /* CONFIG_X86_64 */
/*
* For 32bit only simplified versions of SAVE_ALL/RESTORE_ALL. These
* are different from the entry_32.S versions in not changing the segment
* registers. So only suitable for in kernel use, not when transitioning
* from or to user space. The resulting stack frame is not a standard
* pt_regs frame. The main use case is calling C code from assembler
* when all the registers need to be preserved.
*/
.macro SAVE_ALL
pushl_cfi %eax
CFI_REL_OFFSET eax, 0
pushl_cfi %ebp
CFI_REL_OFFSET ebp, 0
pushl_cfi %edi
CFI_REL_OFFSET edi, 0
pushl_cfi %esi
CFI_REL_OFFSET esi, 0
pushl_cfi %edx
CFI_REL_OFFSET edx, 0
pushl_cfi %ecx
CFI_REL_OFFSET ecx, 0
pushl_cfi %ebx
CFI_REL_OFFSET ebx, 0
.endm
.macro RESTORE_ALL
popl_cfi %ebx
CFI_RESTORE ebx
popl_cfi %ecx
CFI_RESTORE ecx
popl_cfi %edx
CFI_RESTORE edx
popl_cfi %esi
CFI_RESTORE esi
popl_cfi %edi
CFI_RESTORE edi
popl_cfi %ebp
CFI_RESTORE ebp
popl_cfi %eax
CFI_RESTORE eax
.endm
#endif /* CONFIG_X86_64 */

28
arch/x86/include/asm/local.h
View File

@ -52,12 +52,7 @@ static inline void local_sub(long i, local_t *l)
*/
static inline int local_sub_and_test(long i, local_t *l)
{
unsigned char c;
asm volatile(_ASM_SUB "%2,%0; sete %1"
: "+m" (l->a.counter), "=qm" (c)
: "ir" (i) : "memory");
return c;
GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, i, "%0", "e");
}
/**
@ -70,12 +65,7 @@ static inline int local_sub_and_test(long i, local_t *l)
*/
static inline int local_dec_and_test(local_t *l)
{
unsigned char c;
asm volatile(_ASM_DEC "%0; sete %1"
: "+m" (l->a.counter), "=qm" (c)
: : "memory");
return c != 0;
GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, "%0", "e");
}
/**
@ -88,12 +78,7 @@ static inline int local_dec_and_test(local_t *l)
*/
static inline int local_inc_and_test(local_t *l)
{
unsigned char c;
asm volatile(_ASM_INC "%0; sete %1"
: "+m" (l->a.counter), "=qm" (c)
: : "memory");
return c != 0;
GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, "%0", "e");
}
/**
@ -107,12 +92,7 @@ static inline int local_inc_and_test(local_t *l)
*/
static inline int local_add_negative(long i, local_t *l)
{
unsigned char c;
asm volatile(_ASM_ADD "%2,%0; sets %1"
: "+m" (l->a.counter), "=qm" (c)
: "ir" (i) : "memory");
return c;
GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, i, "%0", "s");
}
/**

100
arch/x86/include/asm/preempt.h Normal file
View File

@ -0,0 +1,100 @@
#ifndef __ASM_PREEMPT_H
#define __ASM_PREEMPT_H
#include <asm/rmwcc.h>
#include <asm/percpu.h>
#include <linux/thread_info.h>
DECLARE_PER_CPU(int, __preempt_count);
/*
* We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users
* that think a non-zero value indicates we cannot preempt.
*/
static __always_inline int preempt_count(void)
{
return __this_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED;
}
static __always_inline void preempt_count_set(int pc)
{
__this_cpu_write_4(__preempt_count, pc);
}
/*
* must be macros to avoid header recursion hell
*/
#define task_preempt_count(p) \
(task_thread_info(p)->saved_preempt_count & ~PREEMPT_NEED_RESCHED)
#define init_task_preempt_count(p) do { \
task_thread_info(p)->saved_preempt_count = PREEMPT_DISABLED; \
} while (0)
#define init_idle_preempt_count(p, cpu) do { \
task_thread_info(p)->saved_preempt_count = PREEMPT_ENABLED; \
per_cpu(__preempt_count, (cpu)) = PREEMPT_ENABLED; \
} while (0)
/*
* We fold the NEED_RESCHED bit into the preempt count such that
* preempt_enable() can decrement and test for needing to reschedule with a
* single instruction.
*
* We invert the actual bit, so that when the decrement hits 0 we know we both
* need to resched (the bit is cleared) and can resched (no preempt count).
*/
static __always_inline void set_preempt_need_resched(void)
{
__this_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED);
}
static __always_inline void clear_preempt_need_resched(void)
{
__this_cpu_or_4(__preempt_count, PREEMPT_NEED_RESCHED);
}
static __always_inline bool test_preempt_need_resched(void)
{
return !(__this_cpu_read_4(__preempt_count) & PREEMPT_NEED_RESCHED);
}
/*
* The various preempt_count add/sub methods
*/
static __always_inline void __preempt_count_add(int val)
{
__this_cpu_add_4(__preempt_count, val);
}
static __always_inline void __preempt_count_sub(int val)
{
__this_cpu_add_4(__preempt_count, -val);
}
static __always_inline bool __preempt_count_dec_and_test(void)
{
GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e");
}
/*
* Returns true when we need to resched and can (barring IRQ state).
*/
static __always_inline bool should_resched(void)
{
return unlikely(!__this_cpu_read_4(__preempt_count));
}
#ifdef CONFIG_PREEMPT
extern asmlinkage void ___preempt_schedule(void);
# define __preempt_schedule() asm ("call ___preempt_schedule")
extern asmlinkage void preempt_schedule(void);
# ifdef CONFIG_CONTEXT_TRACKING
extern asmlinkage void ___preempt_schedule_context(void);
# define __preempt_schedule_context() asm ("call ___preempt_schedule_context")
# endif
#endif
#endif /* __ASM_PREEMPT_H */

41
arch/x86/include/asm/rmwcc.h Normal file
View File

@ -0,0 +1,41 @@
#ifndef _ASM_X86_RMWcc
#define _ASM_X86_RMWcc
#ifdef CC_HAVE_ASM_GOTO
#define __GEN_RMWcc(fullop, var, cc, ...) \
do { \
asm_volatile_goto (fullop "; j" cc " %l[cc_label]" \
: : "m" (var), ## __VA_ARGS__ \
: "memory" : cc_label); \
return 0; \
cc_label: \
return 1; \
} while (0)
#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
__GEN_RMWcc(op " " arg0, var, cc)
#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \
__GEN_RMWcc(op " %1, " arg0, var, cc, "er" (val))
#else /* !CC_HAVE_ASM_GOTO */
#define __GEN_RMWcc(fullop, var, cc, ...) \
do { \
char c; \
asm volatile (fullop "; set" cc " %1" \
: "+m" (var), "=qm" (c) \
: __VA_ARGS__ : "memory"); \
return c != 0; \
} while (0)
#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
__GEN_RMWcc(op " " arg0, var, cc)
#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \
__GEN_RMWcc(op " %2, " arg0, var, cc, "er" (val))
#endif /* CC_HAVE_ASM_GOTO */
#endif /* _ASM_X86_RMWcc */

5
arch/x86/include/asm/thread_info.h
View File

@ -28,8 +28,7 @@ struct thread_info {
__u32 flags; /* low level flags */
__u32 status; /* thread synchronous flags */
__u32 cpu; /* current CPU */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
int saved_preempt_count;
mm_segment_t addr_limit;
struct restart_block restart_block;
void __user *sysenter_return;
@ -49,7 +48,7 @@ struct thread_info {
.exec_domain = &default_exec_domain, \
.flags = 0, \
.cpu = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
.saved_preempt_count = INIT_PREEMPT_COUNT, \
.addr_limit = KERNEL_DS, \
.restart_block = { \
.fn = do_no_restart_syscall, \

2
arch/x86/kernel/Makefile
View File

@ -36,6 +36,8 @@ obj-y += tsc.o io_delay.o rtc.o
obj-y += pci-iommu_table.o
obj-y += resource.o
obj-$(CONFIG_PREEMPT) += preempt.o
obj-y += process.o
obj-y += i387.o xsave.o
obj-y += ptrace.o

1
arch/x86/kernel/asm-offsets.c
View File

@ -32,7 +32,6 @@ void common(void) {
OFFSET(TI_flags, thread_info, flags);
OFFSET(TI_status, thread_info, status);
OFFSET(TI_addr_limit, thread_info, addr_limit);
OFFSET(TI_preempt_count, thread_info, preempt_count);
BLANK();
OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);

5
arch/x86/kernel/cpu/common.c
View File

@ -1095,6 +1095,9 @@ DEFINE_PER_CPU(char *, irq_stack_ptr) =
DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
EXPORT_PER_CPU_SYMBOL(__preempt_count);
DEFINE_PER_CPU(struct task_struct *, fpu_owner_task);
/*
@ -1169,6 +1172,8 @@ void debug_stack_reset(void)
DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
EXPORT_PER_CPU_SYMBOL(current_task);
DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
EXPORT_PER_CPU_SYMBOL(__preempt_count);
DEFINE_PER_CPU(struct task_struct *, fpu_owner_task);
#ifdef CONFIG_CC_STACKPROTECTOR

7
arch/x86/kernel/entry_32.S
View File

@ -362,12 +362,9 @@ END(ret_from_exception)
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
DISABLE_INTERRUPTS(CLBR_ANY)
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
jnz restore_all
need_resched:
movl TI_flags(%ebp), %ecx # need_resched set ?
testb $_TIF_NEED_RESCHED, %cl
jz restore_all
cmpl $0,PER_CPU_VAR(__preempt_count)
jnz restore_all
testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
jz restore_all
call preempt_schedule_irq

4
arch/x86/kernel/entry_64.S
View File

@ -1103,10 +1103,8 @@ retint_signal:
/* Returning to kernel space. Check if we need preemption */
/* rcx: threadinfo. interrupts off. */
ENTRY(retint_kernel)
cmpl $0,TI_preempt_count(%rcx)
cmpl $0,PER_CPU_VAR(__preempt_count)
jnz retint_restore_args
bt $TIF_NEED_RESCHED,TI_flags(%rcx)
jnc retint_restore_args
bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
jnc retint_restore_args
call preempt_schedule_irq

7
arch/x86/kernel/i386_ksyms_32.c
View File

@ -37,3 +37,10 @@ EXPORT_SYMBOL(strstr);
EXPORT_SYMBOL(csum_partial);
EXPORT_SYMBOL(empty_zero_page);
#ifdef CONFIG_PREEMPT
EXPORT_SYMBOL(___preempt_schedule);
#ifdef CONFIG_CONTEXT_TRACKING
EXPORT_SYMBOL(___preempt_schedule_context);
#endif
#endif

4
arch/x86/kernel/irq_32.c
View File

@ -100,9 +100,6 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
irqctx->tinfo.task = curctx->tinfo.task;
irqctx->tinfo.previous_esp = current_stack_pointer;
/* Copy the preempt_count so that the [soft]irq checks work. */
irqctx->tinfo.preempt_count = curctx->tinfo.preempt_count;
if (unlikely(overflow))
call_on_stack(print_stack_overflow, isp);
@ -131,7 +128,6 @@ void irq_ctx_init(int cpu)
THREAD_SIZE_ORDER));
memset(&irqctx->tinfo, 0, sizeof(struct thread_info));
irqctx->tinfo.cpu = cpu;
irqctx->tinfo.preempt_count = HARDIRQ_OFFSET;
irqctx->tinfo.addr_limit = MAKE_MM_SEG(0);
per_cpu(hardirq_ctx, cpu) = irqctx;

25
arch/x86/kernel/preempt.S Normal file
View File

@ -0,0 +1,25 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/asm.h>
#include <asm/calling.h>
ENTRY(___preempt_schedule)
CFI_STARTPROC
SAVE_ALL
call preempt_schedule
RESTORE_ALL
ret
CFI_ENDPROC
#ifdef CONFIG_CONTEXT_TRACKING
ENTRY(___preempt_schedule_context)
CFI_STARTPROC
SAVE_ALL
call preempt_schedule_context
RESTORE_ALL
ret
CFI_ENDPROC
#endif

6
arch/x86/kernel/process.c
View File

@ -391,9 +391,9 @@ static void amd_e400_idle(void)
* The switch back from broadcast mode needs to be
* called with interrupts disabled.
*/
local_irq_disable();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
local_irq_enable();
local_irq_disable();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
local_irq_enable();
} else
default_idle();
}

8
arch/x86/kernel/process_32.c
View File

@ -291,6 +291,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
set_iopl_mask(next->iopl);
/*
* If it were not for PREEMPT_ACTIVE we could guarantee that the
* preempt_count of all tasks was equal here and this would not be
* needed.
*/
task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count);
this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count);
/*
* Now maybe handle debug registers and/or IO bitmaps
*/

8
arch/x86/kernel/process_64.c
View File

@ -363,6 +363,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
this_cpu_write(old_rsp, next->usersp);
this_cpu_write(current_task, next_p);
/*
* If it were not for PREEMPT_ACTIVE we could guarantee that the
* preempt_count of all tasks was equal here and this would not be
* needed.
*/
task_thread_info(prev_p)->saved_preempt_count = this_cpu_read(__preempt_count);
this_cpu_write(__preempt_count, task_thread_info(next_p)->saved_preempt_count);
this_cpu_write(kernel_stack,
(unsigned long)task_stack_page(next_p) +
THREAD_SIZE - KERNEL_STACK_OFFSET);

4
arch/x86/kernel/traps.c
View File

@ -88,7 +88,7 @@ static inline void conditional_sti(struct pt_regs *regs)
static inline void preempt_conditional_sti(struct pt_regs *regs)
{
inc_preempt_count();
preempt_count_inc();
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
@ -103,7 +103,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_disable();
dec_preempt_count();
preempt_count_dec();
}
static int __kprobes

7
arch/x86/kernel/x8664_ksyms_64.c
View File

@ -66,3 +66,10 @@ EXPORT_SYMBOL(empty_zero_page);
#ifndef CONFIG_PARAVIRT
EXPORT_SYMBOL(native_load_gs_index);
#endif
#ifdef CONFIG_PREEMPT
EXPORT_SYMBOL(___preempt_schedule);
#ifdef CONFIG_CONTEXT_TRACKING
EXPORT_SYMBOL(___preempt_schedule_context);
#endif
#endif

1
arch/xtensa/include/asm/Kbuild
View File

@ -28,3 +28,4 @@ generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += xor.h
generic-y += preempt.h

46
drivers/acpi/processor_idle.c
View File

@ -119,17 +119,10 @@ static struct dmi_system_id processor_power_dmi_table[] = {
*/
static void acpi_safe_halt(void)
{
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
if (!need_resched()) {
if (!tif_need_resched()) {
safe_halt();
local_irq_disable();
}
current_thread_info()->status |= TS_POLLING;
}
#ifdef ARCH_APICTIMER_STOPS_ON_C3
@ -737,6 +730,11 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
if (unlikely(!pr))
return -EINVAL;
if (cx->entry_method == ACPI_CSTATE_FFH) {
if (current_set_polling_and_test())
return -EINVAL;
}
lapic_timer_state_broadcast(pr, cx, 1);
acpi_idle_do_entry(cx);
@ -790,18 +788,9 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
if (unlikely(!pr))
return -EINVAL;
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we test
* NEED_RESCHED:
*/
smp_mb();
if (unlikely(need_resched())) {
current_thread_info()->status |= TS_POLLING;
if (cx->entry_method == ACPI_CSTATE_FFH) {
if (current_set_polling_and_test())
return -EINVAL;
}
}
/*
@ -819,9 +808,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
sched_clock_idle_wakeup_event(0);
if (cx->entry_method != ACPI_CSTATE_FFH)
current_thread_info()->status |= TS_POLLING;
lapic_timer_state_broadcast(pr, cx, 0);
return index;
}
@ -858,18 +844,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
}
}
if (cx->entry_method != ACPI_CSTATE_FFH) {
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we test
* NEED_RESCHED:
*/
smp_mb();
if (unlikely(need_resched())) {
current_thread_info()->status |= TS_POLLING;
if (cx->entry_method == ACPI_CSTATE_FFH) {
if (current_set_polling_and_test())
return -EINVAL;
}
}
acpi_unlazy_tlb(smp_processor_id());
@ -915,9 +892,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
sched_clock_idle_wakeup_event(0);
if (cx->entry_method != ACPI_CSTATE_FFH)
current_thread_info()->status |= TS_POLLING;
lapic_timer_state_broadcast(pr, cx, 0);
return index;
}

2
drivers/idle/intel_idle.c
View File

@ -359,7 +359,7 @@ static int intel_idle(struct cpuidle_device *dev,
if (!(lapic_timer_reliable_states & (1 << (cstate))))
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
if (!need_resched()) {
if (!current_set_polling_and_test()) {
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();

1
fs/exec.c
View File

@ -1547,6 +1547,7 @@ static int do_execve_common(const char *filename,
current->fs->in_exec = 0;
current->in_execve = 0;
acct_update_integrals(current);
task_numa_free(current);
free_bprm(bprm);
if (displaced)
put_files_struct(displaced);

2
fs/proc/array.c
View File

@ -183,6 +183,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
seq_printf(m,
"State:\t%s\n"
"Tgid:\t%d\n"
"Ngid:\t%d\n"
"Pid:\t%d\n"
"PPid:\t%d\n"
"TracerPid:\t%d\n"
@ -190,6 +191,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
"Gid:\t%d\t%d\t%d\t%d\n",
get_task_state(p),
task_tgid_nr_ns(p, ns),
task_numa_group_id(p),
pid_nr_ns(pid, ns),
ppid, tpid,
from_kuid_munged(user_ns, cred->uid),

105
include/asm-generic/preempt.h Normal file
View File

@ -0,0 +1,105 @@
#ifndef __ASM_PREEMPT_H
#define __ASM_PREEMPT_H
#include <linux/thread_info.h>
/*
* We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users
* that think a non-zero value indicates we cannot preempt.
*/
static __always_inline int preempt_count(void)
{
return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED;
}
static __always_inline int *preempt_count_ptr(void)
{
return &current_thread_info()->preempt_count;
}
/*
* We now loose PREEMPT_NEED_RESCHED and cause an extra reschedule; however the
* alternative is loosing a reschedule. Better schedule too often -- also this
* should be a very rare operation.
*/
static __always_inline void preempt_count_set(int pc)
{
*preempt_count_ptr() = pc;
}
/*
* must be macros to avoid header recursion hell
*/
#define task_preempt_count(p) \
(task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED)
#define init_task_preempt_count(p) do { \
task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
} while (0)
#define init_idle_preempt_count(p, cpu) do { \
task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \
} while (0)
/*
* We fold the NEED_RESCHED bit into the preempt count such that
* preempt_enable() can decrement and test for needing to reschedule with a
* single instruction.
*
* We invert the actual bit, so that when the decrement hits 0 we know we both
* need to resched (the bit is cleared) and can resched (no preempt count).
*/
static __always_inline void set_preempt_need_resched(void)
{
*preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED;
}
static __always_inline void clear_preempt_need_resched(void)
{
*preempt_count_ptr() |= PREEMPT_NEED_RESCHED;
}
static __always_inline bool test_preempt_need_resched(void)
{
return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED);
}
/*
* The various preempt_count add/sub methods
*/
static __always_inline void __preempt_count_add(int val)
{
*preempt_count_ptr() += val;
}
static __always_inline void __preempt_count_sub(int val)
{
*preempt_count_ptr() -= val;
}
static __always_inline bool __preempt_count_dec_and_test(void)
{
return !--*preempt_count_ptr();
}
/*
* Returns true when we need to resched and can (barring IRQ state).
*/
static __always_inline bool should_resched(void)
{
return unlikely(!*preempt_count_ptr());
}
#ifdef CONFIG_PREEMPT
extern asmlinkage void preempt_schedule(void);
#define __preempt_schedule() preempt_schedule()
#ifdef CONFIG_CONTEXT_TRACKING
extern asmlinkage void preempt_schedule_context(void);
#define __preempt_schedule_context() preempt_schedule_context()
#endif
#endif /* CONFIG_PREEMPT */
#endif /* __ASM_PREEMPT_H */

2
include/linux/completion.h
View File

@ -5,7 +5,7 @@
* (C) Copyright 2001 Linus Torvalds
*
* Atomic wait-for-completion handler data structures.
* See kernel/sched/core.c for details.
* See kernel/sched/completion.c for details.
*/
#include <linux/wait.h>

8
include/linux/hardirq.h
View File

@ -33,7 +33,7 @@ extern void rcu_nmi_exit(void);
#define __irq_enter() \
do { \
account_irq_enter_time(current); \
add_preempt_count(HARDIRQ_OFFSET); \
preempt_count_add(HARDIRQ_OFFSET); \
trace_hardirq_enter(); \
} while (0)
@ -49,7 +49,7 @@ extern void irq_enter(void);
do { \
trace_hardirq_exit(); \
account_irq_exit_time(current); \
sub_preempt_count(HARDIRQ_OFFSET); \
preempt_count_sub(HARDIRQ_OFFSET); \
} while (0)
/*
@ -62,7 +62,7 @@ extern void irq_exit(void);
lockdep_off(); \
ftrace_nmi_enter(); \
BUG_ON(in_nmi()); \
add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
rcu_nmi_enter(); \
trace_hardirq_enter(); \
} while (0)
@ -72,7 +72,7 @@ extern void irq_exit(void);
trace_hardirq_exit(); \
rcu_nmi_exit(); \
BUG_ON(!in_nmi()); \
sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \
ftrace_nmi_exit(); \
lockdep_on(); \
} while (0)

1
include/linux/mempolicy.h
View File

@ -136,6 +136,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
struct mempolicy *get_vma_policy(struct task_struct *tsk,
struct vm_area_struct *vma, unsigned long addr);
bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma);
extern void numa_default_policy(void);
extern void numa_policy_init(void);

7
include/linux/migrate.h
View File

@ -90,11 +90,12 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
#endif /* CONFIG_MIGRATION */
#ifdef CONFIG_NUMA_BALANCING
extern int migrate_misplaced_page(struct page *page, int node);
extern int migrate_misplaced_page(struct page *page, int node);
extern int migrate_misplaced_page(struct page *page,
struct vm_area_struct *vma, int node);
extern bool migrate_ratelimited(int node);
#else
static inline int migrate_misplaced_page(struct page *page, int node)
static inline int migrate_misplaced_page(struct page *page,
struct vm_area_struct *vma, int node)
{
return -EAGAIN; /* can't migrate now */
}

118
include/linux/mm.h
View File

@ -581,11 +581,11 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
* sets it, so none of the operations on it need to be atomic.
*/
/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_NID] | ... | FLAGS | */
/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
#define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
#define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
#define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
#define LAST_NID_PGOFF (ZONES_PGOFF - LAST_NID_WIDTH)
#define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
/*
* Define the bit shifts to access each section. For non-existent
@ -595,7 +595,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
#define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
#define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
#define LAST_NID_PGSHIFT (LAST_NID_PGOFF * (LAST_NID_WIDTH != 0))
#define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
#ifdef NODE_NOT_IN_PAGE_FLAGS
@ -617,7 +617,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
#define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
#define NODES_MASK ((1UL << NODES_WIDTH) - 1)
#define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
#define LAST_NID_MASK ((1UL << LAST_NID_WIDTH) - 1)
#define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_WIDTH) - 1)
#define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
static inline enum zone_type page_zonenum(const struct page *page)
@ -661,51 +661,117 @@ static inline int page_to_nid(const struct page *page)
#endif
#ifdef CONFIG_NUMA_BALANCING
#ifdef LAST_NID_NOT_IN_PAGE_FLAGS
static inline int page_nid_xchg_last(struct page *page, int nid)
static inline int cpu_pid_to_cpupid(int cpu, int pid)
{
return xchg(&page->_last_nid, nid);
return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
}
static inline int page_nid_last(struct page *page)
static inline int cpupid_to_pid(int cpupid)
{
return page->_last_nid;
return cpupid & LAST__PID_MASK;
}
static inline void page_nid_reset_last(struct page *page)
static inline int cpupid_to_cpu(int cpupid)
{
page->_last_nid = -1;
return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
}
static inline int cpupid_to_nid(int cpupid)
{
return cpu_to_node(cpupid_to_cpu(cpupid));
}
static inline bool cpupid_pid_unset(int cpupid)
{
return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
}
static inline bool cpupid_cpu_unset(int cpupid)
{
return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
}
static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
{
return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
}
#define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
{
return xchg(&page->_last_cpupid, cpupid);
}
static inline int page_cpupid_last(struct page *page)
{
return page->_last_cpupid;
}
static inline void page_cpupid_reset_last(struct page *page)
{
page->_last_cpupid = -1;
}
#else
static inline int page_nid_last(struct page *page)
static inline int page_cpupid_last(struct page *page)
{
return (page->flags >> LAST_NID_PGSHIFT) & LAST_NID_MASK;
return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
}
extern int page_nid_xchg_last(struct page *page, int nid);
extern int page_cpupid_xchg_last(struct page *page, int cpupid);
static inline void page_nid_reset_last(struct page *page)
static inline void page_cpupid_reset_last(struct page *page)
{
int nid = (1 << LAST_NID_SHIFT) - 1;
int cpupid = (1 << LAST_CPUPID_SHIFT) - 1;
page->flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT);
page->flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT;
page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
}
#endif /* LAST_NID_NOT_IN_PAGE_FLAGS */
#else
static inline int page_nid_xchg_last(struct page *page, int nid)
#endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
#else /* !CONFIG_NUMA_BALANCING */
static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
{
return page_to_nid(page);
return page_to_nid(page); /* XXX */
}
static inline int page_nid_last(struct page *page)
static inline int page_cpupid_last(struct page *page)
{
return page_to_nid(page);
return page_to_nid(page); /* XXX */
}
static inline void page_nid_reset_last(struct page *page)
static inline int cpupid_to_nid(int cpupid)
{
return -1;
}
static inline int cpupid_to_pid(int cpupid)
{
return -1;
}
static inline int cpupid_to_cpu(int cpupid)
{
return -1;
}
static inline int cpu_pid_to_cpupid(int nid, int pid)
{
return -1;
}
static inline bool cpupid_pid_unset(int cpupid)
{
return 1;
}
static inline void page_cpupid_reset_last(struct page *page)
{
}
#endif
static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
{
return false;
}
#endif /* CONFIG_NUMA_BALANCING */
static inline struct zone *page_zone(const struct page *page)
{

17
include/linux/mm_types.h
View File

@ -174,8 +174,8 @@ struct page {
void *shadow;
#endif
#ifdef LAST_NID_NOT_IN_PAGE_FLAGS
int _last_nid;
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
int _last_cpupid;
#endif
}
/*
@ -420,28 +420,15 @@ struct mm_struct {
*/
unsigned long numa_next_scan;
/* numa_next_reset is when the PTE scanner period will be reset */
unsigned long numa_next_reset;
/* Restart point for scanning and setting pte_numa */
unsigned long numa_scan_offset;
/* numa_scan_seq prevents two threads setting pte_numa */
int numa_scan_seq;
/*
* The first node a task was scheduled on. If a task runs on
* a different node than Make PTE Scan Go Now.
*/
int first_nid;
#endif
struct uprobes_state uprobes_state;
};
/* first nid will either be a valid NID or one of these values */
#define NUMA_PTE_SCAN_INIT -1
#define NUMA_PTE_SCAN_ACTIVE -2
static inline void mm_init_cpumask(struct mm_struct *mm)
{
#ifdef CONFIG_CPUMASK_OFFSTACK

28
include/linux/page-flags-layout.h
View File

@ -38,10 +38,10 @@
* The last is when there is insufficient space in page->flags and a separate
* lookup is necessary.
*
* No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS |
* " plus space for last_nid: | NODE | ZONE | LAST_NID ... | FLAGS |
* classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
* " plus space for last_nid: | SECTION | NODE | ZONE | LAST_NID ... | FLAGS |
* No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS |
* " plus space for last_cpupid: | NODE | ZONE | LAST_CPUPID ... | FLAGS |
* classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
* " plus space for last_cpupid: | SECTION | NODE | ZONE | LAST_CPUPID ... | FLAGS |
* classic sparse no space for node: | SECTION | ZONE | ... | FLAGS |
*/
#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
@ -62,15 +62,21 @@
#endif
#ifdef CONFIG_NUMA_BALANCING
#define LAST_NID_SHIFT NODES_SHIFT
#define LAST__PID_SHIFT 8
#define LAST__PID_MASK ((1 << LAST__PID_SHIFT)-1)
#define LAST__CPU_SHIFT NR_CPUS_BITS
#define LAST__CPU_MASK ((1 << LAST__CPU_SHIFT)-1)
#define LAST_CPUPID_SHIFT (LAST__PID_SHIFT+LAST__CPU_SHIFT)
#else
#define LAST_NID_SHIFT 0
#define LAST_CPUPID_SHIFT 0
#endif
#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_NID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
#define LAST_NID_WIDTH LAST_NID_SHIFT
#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
#define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT
#else
#define LAST_NID_WIDTH 0
#define LAST_CPUPID_WIDTH 0
#endif
/*
@ -81,8 +87,8 @@
#define NODE_NOT_IN_PAGE_FLAGS
#endif
#if defined(CONFIG_NUMA_BALANCING) && LAST_NID_WIDTH == 0
#define LAST_NID_NOT_IN_PAGE_FLAGS
#if defined(CONFIG_NUMA_BALANCING) && LAST_CPUPID_WIDTH == 0
#define LAST_CPUPID_NOT_IN_PAGE_FLAGS
#endif
#endif /* _LINUX_PAGE_FLAGS_LAYOUT */

112
include/linux/preempt.h
View File

@ -6,106 +6,95 @@
* preempt_count (used for kernel preemption, interrupt count, etc.)
*/
#include <linux/thread_info.h>
#include <linux/linkage.h>
#include <linux/list.h>
/*
* We use the MSB mostly because its available; see <linux/preempt_mask.h> for
* the other bits -- can't include that header due to inclusion hell.
*/
#define PREEMPT_NEED_RESCHED 0x80000000
#include <asm/preempt.h>
#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
extern void add_preempt_count(int val);
extern void sub_preempt_count(int val);
extern void preempt_count_add(int val);
extern void preempt_count_sub(int val);
#define preempt_count_dec_and_test() ({ preempt_count_sub(1); should_resched(); })
#else
# define add_preempt_count(val) do { preempt_count() += (val); } while (0)
# define sub_preempt_count(val) do { preempt_count() -= (val); } while (0)
#define preempt_count_add(val) __preempt_count_add(val)
#define preempt_count_sub(val) __preempt_count_sub(val)
#define preempt_count_dec_and_test() __preempt_count_dec_and_test()
#endif
#define inc_preempt_count() add_preempt_count(1)
#define dec_preempt_count() sub_preempt_count(1)
#define preempt_count() (current_thread_info()->preempt_count)
#ifdef CONFIG_PREEMPT
asmlinkage void preempt_schedule(void);
#define preempt_check_resched() \
do { \
if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
preempt_schedule(); \
} while (0)
#ifdef CONFIG_CONTEXT_TRACKING
void preempt_schedule_context(void);
#define preempt_check_resched_context() \
do { \
if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
preempt_schedule_context(); \
} while (0)
#else
#define preempt_check_resched_context() preempt_check_resched()
#endif /* CONFIG_CONTEXT_TRACKING */
#else /* !CONFIG_PREEMPT */
#define preempt_check_resched() do { } while (0)
#define preempt_check_resched_context() do { } while (0)
#endif /* CONFIG_PREEMPT */
#define __preempt_count_inc() __preempt_count_add(1)
#define __preempt_count_dec() __preempt_count_sub(1)
#define preempt_count_inc() preempt_count_add(1)
#define preempt_count_dec() preempt_count_sub(1)
#ifdef CONFIG_PREEMPT_COUNT
#define preempt_disable() \
do { \
inc_preempt_count(); \
preempt_count_inc(); \
barrier(); \
} while (0)
#define sched_preempt_enable_no_resched() \
do { \
barrier(); \
dec_preempt_count(); \
preempt_count_dec(); \
} while (0)
#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
#ifdef CONFIG_PREEMPT
#define preempt_enable() \
do { \
preempt_enable_no_resched(); \
barrier(); \
preempt_check_resched(); \
if (unlikely(preempt_count_dec_and_test())) \
__preempt_schedule(); \
} while (0)
/* For debugging and tracer internals only! */
#define add_preempt_count_notrace(val) \
do { preempt_count() += (val); } while (0)
#define sub_preempt_count_notrace(val) \
do { preempt_count() -= (val); } while (0)
#define inc_preempt_count_notrace() add_preempt_count_notrace(1)
#define dec_preempt_count_notrace() sub_preempt_count_notrace(1)
#define preempt_check_resched() \
do { \
if (should_resched()) \
__preempt_schedule(); \
} while (0)
#else
#define preempt_enable() preempt_enable_no_resched()
#define preempt_check_resched() do { } while (0)
#endif
#define preempt_disable_notrace() \
do { \
inc_preempt_count_notrace(); \
__preempt_count_inc(); \
barrier(); \
} while (0)
#define preempt_enable_no_resched_notrace() \
do { \
barrier(); \
dec_preempt_count_notrace(); \
__preempt_count_dec(); \
} while (0)
/* preempt_check_resched is OK to trace */
#ifdef CONFIG_PREEMPT
#ifndef CONFIG_CONTEXT_TRACKING
#define __preempt_schedule_context() __preempt_schedule()
#endif
#define preempt_enable_notrace() \
do { \
preempt_enable_no_resched_notrace(); \
barrier(); \
preempt_check_resched_context(); \
if (unlikely(__preempt_count_dec_and_test())) \
__preempt_schedule_context(); \
} while (0)
#else
#define preempt_enable_notrace() preempt_enable_no_resched_notrace()
#endif
#else /* !CONFIG_PREEMPT_COUNT */
@ -115,10 +104,11 @@ do { \
* that can cause faults and scheduling migrate into our preempt-protected
* region.
*/
#define preempt_disable() barrier()
#define preempt_disable() barrier()
#define sched_preempt_enable_no_resched() barrier()
#define preempt_enable_no_resched() barrier()
#define preempt_enable() barrier()
#define preempt_enable_no_resched() barrier()
#define preempt_enable() barrier()
#define preempt_check_resched() do { } while (0)
#define preempt_disable_notrace() barrier()
#define preempt_enable_no_resched_notrace() barrier()

167
include/linux/sched.h
View File

@ -22,6 +22,7 @@ struct sched_param {
#include <linux/errno.h>
#include <linux/nodemask.h>
#include <linux/mm_types.h>
#include <linux/preempt.h>
#include <asm/page.h>
#include <asm/ptrace.h>
@ -427,6 +428,14 @@ struct task_cputime {
.sum_exec_runtime = 0, \
}
#define PREEMPT_ENABLED (PREEMPT_NEED_RESCHED)
#ifdef CONFIG_PREEMPT_COUNT
#define PREEMPT_DISABLED (1 + PREEMPT_ENABLED)
#else
#define PREEMPT_DISABLED PREEMPT_ENABLED
#endif
/*
* Disable preemption until the scheduler is running.
* Reset by start_kernel()->sched_init()->init_idle().
@ -434,7 +443,7 @@ struct task_cputime {
* We include PREEMPT_ACTIVE to avoid cond_resched() from working
* before the scheduler is active -- see should_resched().
*/
#define INIT_PREEMPT_COUNT (1 + PREEMPT_ACTIVE)
#define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE)
/**
* struct thread_group_cputimer - thread group interval timer counts
@ -768,6 +777,7 @@ enum cpu_idle_type {
#define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */
#define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
#define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */
#define SD_NUMA 0x4000 /* cross-node balancing */
extern int __weak arch_sd_sibiling_asym_packing(void);
@ -811,6 +821,10 @@ struct sched_domain {
u64 last_update;
/* idle_balance() stats */
u64 max_newidle_lb_cost;
unsigned long next_decay_max_lb_cost;
#ifdef CONFIG_SCHEDSTATS
/* load_balance() stats */
unsigned int lb_count[CPU_MAX_IDLE_TYPES];
@ -1029,6 +1043,8 @@ struct task_struct {
struct task_struct *last_wakee;
unsigned long wakee_flips;
unsigned long wakee_flip_decay_ts;
int wake_cpu;
#endif
int on_rq;
@ -1324,10 +1340,41 @@ struct task_struct {
#endif
#ifdef CONFIG_NUMA_BALANCING
int numa_scan_seq;
int numa_migrate_seq;
unsigned int numa_scan_period;
unsigned int numa_scan_period_max;
int numa_preferred_nid;
int numa_migrate_deferred;
unsigned long numa_migrate_retry;
u64 node_stamp; /* migration stamp */
struct callback_head numa_work;
struct list_head numa_entry;
struct numa_group *numa_group;
/*
* Exponential decaying average of faults on a per-node basis.
* Scheduling placement decisions are made based on the these counts.
* The values remain static for the duration of a PTE scan
*/
unsigned long *numa_faults;
unsigned long total_numa_faults;
/*
* numa_faults_buffer records faults per node during the current
* scan window. When the scan completes, the counts in numa_faults
* decay and these values are copied.
*/
unsigned long *numa_faults_buffer;
/*
* numa_faults_locality tracks if faults recorded during the last
* scan window were remote/local. The task scan period is adapted
* based on the locality of the faults with different weights
* depending on whether they were shared or private faults
*/
unsigned long numa_faults_locality[2];
unsigned long numa_pages_migrated;
#endif /* CONFIG_NUMA_BALANCING */
struct rcu_head rcu;
@ -1412,16 +1459,33 @@ struct task_struct {
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
#define TNF_MIGRATED 0x01
#define TNF_NO_GROUP 0x02
#define TNF_SHARED 0x04
#define TNF_FAULT_LOCAL 0x08
#ifdef CONFIG_NUMA_BALANCING
extern void task_numa_fault(int node, int pages, bool migrated);
extern void task_numa_fault(int last_node, int node, int pages, int flags);
extern pid_t task_numa_group_id(struct task_struct *p);
extern void set_numabalancing_state(bool enabled);
extern void task_numa_free(struct task_struct *p);
extern unsigned int sysctl_numa_balancing_migrate_deferred;
#else
static inline void task_numa_fault(int node, int pages, bool migrated)
static inline void task_numa_fault(int last_node, int node, int pages,
int flags)
{
}
static inline pid_t task_numa_group_id(struct task_struct *p)
{
return 0;
}
static inline void set_numabalancing_state(bool enabled)
{
}
static inline void task_numa_free(struct task_struct *p)
{
}
#endif
static inline struct pid *task_pid(struct task_struct *task)
@ -1974,7 +2038,7 @@ extern void wake_up_new_task(struct task_struct *tsk);
#else
static inline void kick_process(struct task_struct *tsk) { }
#endif
extern void sched_fork(struct task_struct *p);
extern void sched_fork(unsigned long clone_flags, struct task_struct *p);
extern void sched_dead(struct task_struct *p);
extern void proc_caches_init(void);
@ -2401,11 +2465,6 @@ static inline int signal_pending_state(long state, struct task_struct *p)
return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
}
static inline int need_resched(void)
{
return unlikely(test_thread_flag(TIF_NEED_RESCHED));
}
/*
* cond_resched() and cond_resched_lock(): latency reduction via
* explicit rescheduling in places that are safe. The return
@ -2474,36 +2533,105 @@ static inline int tsk_is_polling(struct task_struct *p)
{
return task_thread_info(p)->status & TS_POLLING;
}
static inline void current_set_polling(void)
static inline void __current_set_polling(void)
{
current_thread_info()->status |= TS_POLLING;
}
static inline void current_clr_polling(void)
static inline bool __must_check current_set_polling_and_test(void)
{
__current_set_polling();
/*
* Polling state must be visible before we test NEED_RESCHED,
* paired by resched_task()
*/
smp_mb();
return unlikely(tif_need_resched());
}
static inline void __current_clr_polling(void)
{
current_thread_info()->status &= ~TS_POLLING;
smp_mb__after_clear_bit();
}
static inline bool __must_check current_clr_polling_and_test(void)
{
__current_clr_polling();
/*
* Polling state must be visible before we test NEED_RESCHED,
* paired by resched_task()
*/
smp_mb();
return unlikely(tif_need_resched());
}
#elif defined(TIF_POLLING_NRFLAG)
static inline int tsk_is_polling(struct task_struct *p)
{
return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
}
static inline void current_set_polling(void)
static inline void __current_set_polling(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
}
static inline void current_clr_polling(void)
static inline bool __must_check current_set_polling_and_test(void)
{
__current_set_polling();
/*
* Polling state must be visible before we test NEED_RESCHED,
* paired by resched_task()
*
* XXX: assumes set/clear bit are identical barrier wise.
*/
smp_mb__after_clear_bit();
return unlikely(tif_need_resched());
}
static inline void __current_clr_polling(void)
{
clear_thread_flag(TIF_POLLING_NRFLAG);
}
static inline bool __must_check current_clr_polling_and_test(void)
{
__current_clr_polling();
/*
* Polling state must be visible before we test NEED_RESCHED,
* paired by resched_task()
*/
smp_mb__after_clear_bit();
return unlikely(tif_need_resched());
}
#else
static inline int tsk_is_polling(struct task_struct *p) { return 0; }
static inline void current_set_polling(void) { }
static inline void current_clr_polling(void) { }
static inline void __current_set_polling(void) { }
static inline void __current_clr_polling(void) { }
static inline bool __must_check current_set_polling_and_test(void)
{
return unlikely(tif_need_resched());
}
static inline bool __must_check current_clr_polling_and_test(void)
{
return unlikely(tif_need_resched());
}
#endif
static __always_inline bool need_resched(void)
{
return unlikely(tif_need_resched());
}
/*
* Thread group CPU time accounting.
*/
@ -2545,6 +2673,11 @@ static inline unsigned int task_cpu(const struct task_struct *p)
return task_thread_info(p)->cpu;
}
static inline int task_node(const struct task_struct *p)
{
return cpu_to_node(task_cpu(p));
}
extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
#else

1
include/linux/sched/sysctl.h
View File

@ -47,7 +47,6 @@ extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
extern unsigned int sysctl_numa_balancing_scan_delay;
extern unsigned int sysctl_numa_balancing_scan_period_min;
extern unsigned int sysctl_numa_balancing_scan_period_max;
extern unsigned int sysctl_numa_balancing_scan_period_reset;
extern unsigned int sysctl_numa_balancing_scan_size;
extern unsigned int sysctl_numa_balancing_settle_count;

1
include/linux/stop_machine.h
View File

@ -28,6 +28,7 @@ struct cpu_stop_work {
};
int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg);
int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg);
void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
struct cpu_stop_work *work_buf);
int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);

17
include/linux/thread_info.h
View File

@ -104,8 +104,21 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
#define test_thread_flag(flag) \
test_ti_thread_flag(current_thread_info(), flag)
#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED)
#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED)
static inline __deprecated void set_need_resched(void)
{
/*
* Use of this function in deprecated.
*
* As of this writing there are only a few users in the DRM tree left
* all of which are wrong and can be removed without causing too much
* grief.
*
* The DRM people are aware and are working on removing the last few
* instances.
*/
}
#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
#if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
/*

6
include/linux/topology.h
View File

@ -106,6 +106,8 @@ int arch_update_cpu_topology(void);
.last_balance = jiffies, \
.balance_interval = 1, \
.smt_gain = 1178, /* 15% */ \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#endif
#endif /* CONFIG_SCHED_SMT */
@ -135,6 +137,8 @@ int arch_update_cpu_topology(void);
, \
.last_balance = jiffies, \
.balance_interval = 1, \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#endif
#endif /* CONFIG_SCHED_MC */
@ -166,6 +170,8 @@ int arch_update_cpu_topology(void);
, \
.last_balance = jiffies, \
.balance_interval = 1, \
.max_newidle_lb_cost = 0, \
.next_decay_max_lb_cost = jiffies, \
}
#endif

28
include/linux/tty.h
View File

@ -672,31 +672,17 @@ static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
#define wait_event_interruptible_tty(tty, wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) { \
__wait_event_interruptible_tty(tty, wq, condition, __ret); \
} \
if (!(condition)) \
__ret = __wait_event_interruptible_tty(tty, wq, \
condition); \
__ret; \
})
#define __wait_event_interruptible_tty(tty, wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (!signal_pending(current)) { \
tty_unlock(tty); \
#define __wait_event_interruptible_tty(tty, wq, condition) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
tty_unlock(tty); \
schedule(); \
tty_lock(tty); \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)
tty_lock(tty))
#ifdef CONFIG_PROC_FS
extern void proc_tty_register_driver(struct tty_driver *);

8
include/linux/uaccess.h
View File

@ -15,7 +15,7 @@
*/
static inline void pagefault_disable(void)
{
inc_preempt_count();
preempt_count_inc();
/*
* make sure to have issued the store before a pagefault
* can hit.
@ -30,11 +30,7 @@ static inline void pagefault_enable(void)
* the pagefault handler again.
*/
barrier();
dec_preempt_count();
/*
* make sure we do..
*/
barrier();
preempt_count_dec();
preempt_check_resched();
}

374
include/linux/wait.h
View File

@ -1,7 +1,8 @@
#ifndef _LINUX_WAIT_H
#define _LINUX_WAIT_H
/*
* Linux wait queue related types and methods
*/
#include <linux/list.h>
#include <linux/stddef.h>
#include <linux/spinlock.h>
@ -13,27 +14,27 @@ typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, v
int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
struct __wait_queue {
unsigned int flags;
unsigned int flags;
#define WQ_FLAG_EXCLUSIVE 0x01
void *private;
wait_queue_func_t func;
struct list_head task_list;
void *private;
wait_queue_func_t func;
struct list_head task_list;
};
struct wait_bit_key {
void *flags;
int bit_nr;
#define WAIT_ATOMIC_T_BIT_NR -1
void *flags;
int bit_nr;
#define WAIT_ATOMIC_T_BIT_NR -1
};
struct wait_bit_queue {
struct wait_bit_key key;
wait_queue_t wait;
struct wait_bit_key key;
wait_queue_t wait;
};
struct __wait_queue_head {
spinlock_t lock;
struct list_head task_list;
spinlock_t lock;
struct list_head task_list;
};
typedef struct __wait_queue_head wait_queue_head_t;
@ -84,17 +85,17 @@ extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct
static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
{
q->flags = 0;
q->private = p;
q->func = default_wake_function;
q->flags = 0;
q->private = p;
q->func = default_wake_function;
}
static inline void init_waitqueue_func_entry(wait_queue_t *q,
wait_queue_func_t func)
static inline void
init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func)
{
q->flags = 0;
q->private = NULL;
q->func = func;
q->flags = 0;
q->private = NULL;
q->func = func;
}
static inline int waitqueue_active(wait_queue_head_t *q)
@ -114,8 +115,8 @@ static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
/*
* Used for wake-one threads:
*/
static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
wait_queue_t *wait)
static inline void
__add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
{
wait->flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue(q, wait);
@ -127,23 +128,22 @@ static inline void __add_wait_queue_tail(wait_queue_head_t *head,
list_add_tail(&new->task_list, &head->task_list);
}
static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
wait_queue_t *wait)
static inline void
__add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
{
wait->flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue_tail(q, wait);
}
static inline void __remove_wait_queue(wait_queue_head_t *head,
wait_queue_t *old)
static inline void
__remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old)
{
list_del(&old->task_list);
}
void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
void *key);
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
void __wake_up_bit(wait_queue_head_t *, void *, int);
@ -170,27 +170,64 @@ wait_queue_head_t *bit_waitqueue(void *, int);
/*
* Wakeup macros to be used to report events to the targets.
*/
#define wake_up_poll(x, m) \
#define wake_up_poll(x, m) \
__wake_up(x, TASK_NORMAL, 1, (void *) (m))
#define wake_up_locked_poll(x, m) \
#define wake_up_locked_poll(x, m) \
__wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
#define wake_up_interruptible_poll(x, m) \
#define wake_up_interruptible_poll(x, m) \
__wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
#define wake_up_interruptible_sync_poll(x, m) \
__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
#define __wait_event(wq, condition) \
do { \
DEFINE_WAIT(__wait); \
#define ___wait_cond_timeout(condition) \
({ \
bool __cond = (condition); \
if (__cond && !__ret) \
__ret = 1; \
__cond || !__ret; \
})
#define ___wait_is_interruptible(state) \
(!__builtin_constant_p(state) || \
state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
#define ___wait_event(wq, condition, state, exclusive, ret, cmd) \
({ \
__label__ __out; \
wait_queue_t __wait; \
long __ret = ret; \
\
INIT_LIST_HEAD(&__wait.task_list); \
if (exclusive) \
__wait.flags = WQ_FLAG_EXCLUSIVE; \
else \
__wait.flags = 0; \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
long __int = prepare_to_wait_event(&wq, &__wait, state);\
\
if (condition) \
break; \
schedule(); \
\
if (___wait_is_interruptible(state) && __int) { \
__ret = __int; \
if (exclusive) { \
abort_exclusive_wait(&wq, &__wait, \
state, NULL); \
goto __out; \
} \
break; \
} \
\
cmd; \
} \
finish_wait(&wq, &__wait); \
} while (0)
__out: __ret; \
})
#define __wait_event(wq, condition) \
(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
schedule())
/**
* wait_event - sleep until a condition gets true
@ -204,29 +241,17 @@ do { \
* wake_up() has to be called after changing any variable that could
* change the result of the wait condition.
*/
#define wait_event(wq, condition) \
#define wait_event(wq, condition) \
do { \
if (condition) \
if (condition) \
break; \
__wait_event(wq, condition); \
} while (0)
#define __wait_event_timeout(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
if (condition) \
break; \
ret = schedule_timeout(ret); \
if (!ret) \
break; \
} \
if (!ret && (condition)) \
ret = 1; \
finish_wait(&wq, &__wait); \
} while (0)
#define __wait_event_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_UNINTERRUPTIBLE, 0, timeout, \
__ret = schedule_timeout(__ret))
/**
* wait_event_timeout - sleep until a condition gets true or a timeout elapses
@ -248,28 +273,14 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!(condition)) \
__wait_event_timeout(wq, condition, __ret); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
#define __wait_event_interruptible(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (!signal_pending(current)) { \
schedule(); \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)
#define __wait_event_interruptible(wq, condition) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
schedule())
/**
* wait_event_interruptible - sleep until a condition gets true
@ -290,31 +301,14 @@ do { \
({ \
int __ret = 0; \
if (!(condition)) \
__wait_event_interruptible(wq, condition, __ret); \
__ret = __wait_event_interruptible(wq, condition); \
__ret; \
})
#define __wait_event_interruptible_timeout(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (!signal_pending(current)) { \
ret = schedule_timeout(ret); \
if (!ret) \
break; \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
if (!ret && (condition)) \
ret = 1; \
finish_wait(&wq, &__wait); \
} while (0)
#define __wait_event_interruptible_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_INTERRUPTIBLE, 0, timeout, \
__ret = schedule_timeout(__ret))
/**
* wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
@ -337,15 +331,15 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!(condition)) \
__wait_event_interruptible_timeout(wq, condition, __ret); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
__ret; \
})
#define __wait_event_hrtimeout(wq, condition, timeout, state) \
({ \
int __ret = 0; \
DEFINE_WAIT(__wait); \
struct hrtimer_sleeper __t; \
\
hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \
@ -356,25 +350,15 @@ do { \
current->timer_slack_ns, \
HRTIMER_MODE_REL); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, state); \
if (condition) \
break; \
if (state == TASK_INTERRUPTIBLE && \
signal_pending(current)) { \
__ret = -ERESTARTSYS; \
break; \
} \
__ret = ___wait_event(wq, condition, state, 0, 0, \
if (!__t.task) { \
__ret = -ETIME; \
break; \
} \
schedule(); \
} \
schedule()); \
\
hrtimer_cancel(&__t.timer); \
destroy_hrtimer_on_stack(&__t.timer); \
finish_wait(&wq, &__wait); \
__ret; \
})
@ -428,33 +412,15 @@ do { \
__ret; \
})
#define __wait_event_interruptible_exclusive(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait_exclusive(&wq, &__wait, \
TASK_INTERRUPTIBLE); \
if (condition) { \
finish_wait(&wq, &__wait); \
break; \
} \
if (!signal_pending(current)) { \
schedule(); \
continue; \
} \
ret = -ERESTARTSYS; \
abort_exclusive_wait(&wq, &__wait, \
TASK_INTERRUPTIBLE, NULL); \
break; \
} \
} while (0)
#define __wait_event_interruptible_exclusive(wq, condition) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
schedule())
#define wait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) \
__wait_event_interruptible_exclusive(wq, condition, __ret);\
__ret = __wait_event_interruptible_exclusive(wq, condition);\
__ret; \
})
@ -606,24 +572,8 @@ do { \
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
#define __wait_event_killable(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
if (condition) \
break; \
if (!fatal_signal_pending(current)) { \
schedule(); \
continue; \
} \
ret = -ERESTARTSYS; \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)
#define __wait_event_killable(wq, condition) \
___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
/**
* wait_event_killable - sleep until a condition gets true
@ -644,26 +594,17 @@ do { \
({ \
int __ret = 0; \
if (!(condition)) \
__wait_event_killable(wq, condition, __ret); \
__ret = __wait_event_killable(wq, condition); \
__ret; \
})
#define __wait_event_lock_irq(wq, condition, lock, cmd) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
if (condition) \
break; \
spin_unlock_irq(&lock); \
cmd; \
schedule(); \
spin_lock_irq(&lock); \
} \
finish_wait(&wq, &__wait); \
} while (0)
(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
spin_unlock_irq(&lock); \
cmd; \
schedule(); \
spin_lock_irq(&lock))
/**
* wait_event_lock_irq_cmd - sleep until a condition gets true. The
@ -723,26 +664,12 @@ do { \
} while (0)
#define __wait_event_interruptible_lock_irq(wq, condition, \
lock, ret, cmd) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (signal_pending(current)) { \
ret = -ERESTARTSYS; \
break; \
} \
spin_unlock_irq(&lock); \
cmd; \
schedule(); \
spin_lock_irq(&lock); \
} \
finish_wait(&wq, &__wait); \
} while (0)
#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \
___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
spin_unlock_irq(&lock); \
cmd; \
schedule(); \
spin_lock_irq(&lock))
/**
* wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
@ -772,10 +699,9 @@ do { \
#define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
({ \
int __ret = 0; \
\
if (!(condition)) \
__wait_event_interruptible_lock_irq(wq, condition, \
lock, __ret, cmd); \
__ret = __wait_event_interruptible_lock_irq(wq, \
condition, lock, cmd); \
__ret; \
})
@ -804,39 +730,24 @@ do { \
#define wait_event_interruptible_lock_irq(wq, condition, lock) \
({ \
int __ret = 0; \
\
if (!(condition)) \
__wait_event_interruptible_lock_irq(wq, condition, \
lock, __ret, ); \
__ret = __wait_event_interruptible_lock_irq(wq, \
condition, lock,); \
__ret; \
})
#define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
lock, ret) \
do { \
DEFINE_WAIT(__wait); \
\
for (;;) { \
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
if (condition) \
break; \
if (signal_pending(current)) { \
ret = -ERESTARTSYS; \
break; \
} \
spin_unlock_irq(&lock); \
ret = schedule_timeout(ret); \
spin_lock_irq(&lock); \
if (!ret) \
break; \
} \
finish_wait(&wq, &__wait); \
} while (0)
lock, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_INTERRUPTIBLE, 0, timeout, \
spin_unlock_irq(&lock); \
__ret = schedule_timeout(__ret); \
spin_lock_irq(&lock));
/**
* wait_event_interruptible_lock_irq_timeout - sleep until a condition gets true or a timeout elapses.
* The condition is checked under the lock. This is expected
* to be called with the lock taken.
* wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
* true or a timeout elapses. The condition is checked under
* the lock. This is expected to be called with the lock taken.
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
* @lock: a locked spinlock_t, which will be released before schedule()
@ -860,11 +771,10 @@ do { \
#define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \
timeout) \
({ \
int __ret = timeout; \
\
if (!(condition)) \
__wait_event_interruptible_lock_irq_timeout( \
wq, condition, lock, __ret); \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_lock_irq_timeout( \
wq, condition, lock, timeout); \
__ret; \
})
@ -875,20 +785,18 @@ do { \
* We plan to remove these interfaces.
*/
extern void sleep_on(wait_queue_head_t *q);
extern long sleep_on_timeout(wait_queue_head_t *q,
signed long timeout);
extern long sleep_on_timeout(wait_queue_head_t *q, signed long timeout);
extern void interruptible_sleep_on(wait_queue_head_t *q);
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
signed long timeout);
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long timeout);
/*
* Waitqueues which are removed from the waitqueue_head at wakeup time
*/
void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state);
void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
unsigned int mode, void *key);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key);
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
@ -934,8 +842,8 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
* One uses wait_on_bit() where one is waiting for the bit to clear,
* but has no intention of setting it.
*/
static inline int wait_on_bit(void *word, int bit,
int (*action)(void *), unsigned mode)
static inline int
wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode)
{
if (!test_bit(bit, word))
return 0;
@ -958,8 +866,8 @@ static inline int wait_on_bit(void *word, int bit,
* One uses wait_on_bit_lock() where one is waiting for the bit to
* clear with the intention of setting it, and when done, clearing it.
*/
static inline int wait_on_bit_lock(void *word, int bit,
int (*action)(void *), unsigned mode)
static inline int
wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode)
{
if (!test_and_set_bit(bit, word))
return 0;
@ -983,5 +891,5 @@ int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
return 0;
return out_of_line_wait_on_atomic_t(val, action, mode);
}
#endif
#endif /* _LINUX_WAIT_H */

2
include/trace/events/sched.h
View File

@ -100,7 +100,7 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
/*
* For all intents and purposes a preempted task is a running task.
*/
if (task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)
if (task_preempt_count(p) & PREEMPT_ACTIVE)
state = TASK_RUNNING | TASK_STATE_MAX;
#endif

2
init/main.c
View File

@ -693,7 +693,7 @@ int __init_or_module do_one_initcall(initcall_t fn)
if (preempt_count() != count) {
sprintf(msgbuf, "preemption imbalance ");
preempt_count() = count;
preempt_count_set(count);
}
if (irqs_disabled()) {
strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));

2
kernel/Makefile
View File

@ -7,7 +7,7 @@ obj-y = fork.o exec_domain.o panic.o \
sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
extable.o params.o posix-timers.o \
kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \
kthread.o sys_ni.o posix-cpu-timers.o mutex.o \
hrtimer.o rwsem.o nsproxy.o semaphore.o \
notifier.o ksysfs.o cred.o reboot.o \
async.o range.o groups.o lglock.o smpboot.o

4
kernel/bounds.c
View File

@ -10,6 +10,7 @@
#include <linux/mmzone.h>
#include <linux/kbuild.h>
#include <linux/page_cgroup.h>
#include <linux/log2.h>
void foo(void)
{
@ -17,5 +18,8 @@ void foo(void)
DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);
DEFINE(NR_PCG_FLAGS, __NR_PCG_FLAGS);
#ifdef CONFIG_SMP
DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS));
#endif
/* End of constants */
}

2
kernel/context_tracking.c
View File

@ -120,7 +120,7 @@ void context_tracking_user_enter(void)
* instead of preempt_schedule() to exit user context if needed before
* calling the scheduler.
*/
void __sched notrace preempt_schedule_context(void)
asmlinkage void __sched notrace preempt_schedule_context(void)
{
enum ctx_state prev_ctx;

17
kernel/cpu.c
View File

@ -308,6 +308,23 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
}
smpboot_park_threads(cpu);
/*
* By now we've cleared cpu_active_mask, wait for all preempt-disabled
* and RCU users of this state to go away such that all new such users
* will observe it.
*
* For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
* not imply sync_sched(), so explicitly call both.
*/
#ifdef CONFIG_PREEMPT
synchronize_sched();
#endif
synchronize_rcu();
/*
* So now all preempt/rcu users must observe !cpu_active().
*/
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */

16
kernel/cpu/idle.c
View File

@ -44,7 +44,7 @@ static inline int cpu_idle_poll(void)
rcu_idle_enter();
trace_cpu_idle_rcuidle(0, smp_processor_id());
local_irq_enable();
while (!need_resched())
while (!tif_need_resched())
cpu_relax();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
rcu_idle_exit();
@ -92,8 +92,7 @@ static void cpu_idle_loop(void)
if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
cpu_idle_poll();
} else {
current_clr_polling();
if (!need_resched()) {
if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
arch_cpu_idle();
@ -103,9 +102,16 @@ static void cpu_idle_loop(void)
} else {
local_irq_enable();
}
current_set_polling();
__current_set_polling();
}
arch_cpu_idle_exit();
/*
* We need to test and propagate the TIF_NEED_RESCHED
* bit here because we might not have send the
* reschedule IPI to idle tasks.
*/
if (tif_need_resched())
set_preempt_need_resched();
}
tick_nohz_idle_exit();
schedule_preempt_disabled();
@ -129,7 +135,7 @@ void cpu_startup_entry(enum cpuhp_state state)
*/
boot_init_stack_canary();
#endif
current_set_polling();
__current_set_polling();
arch_cpu_idle_prepare();
cpu_idle_loop();
}

5
kernel/fork.c
View File

@ -816,9 +816,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
mm->pmd_huge_pte = NULL;
#endif
#ifdef CONFIG_NUMA_BALANCING
mm->first_nid = NUMA_PTE_SCAN_INIT;
#endif
if (!mm_init(mm, tsk))
goto fail_nomem;
@ -1313,7 +1310,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#endif
/* Perform scheduler related setup. Assign this task to a CPU. */
sched_fork(p);
sched_fork(clone_flags, p);
retval = perf_event_init_task(p);
if (retval)

15
kernel/rcu/tree.c
View File

@ -916,6 +916,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
force_quiescent_state(rsp); /* Kick them all. */
}
/*
* This function really isn't for public consumption, but RCU is special in
* that context switches can allow the state machine to make progress.
*/
extern void resched_cpu(int cpu);
static void print_cpu_stall(struct rcu_state *rsp)
{
int cpu;
@ -945,7 +951,14 @@ static void print_cpu_stall(struct rcu_state *rsp)
3 * rcu_jiffies_till_stall_check() + 3;
raw_spin_unlock_irqrestore(&rnp->lock, flags);
set_need_resched(); /* kick ourselves to get things going. */
/*
* Attempt to revive the RCU machinery by forcing a context switch.
*
* A context switch would normally allow the RCU state machine to make
* progress and it could be we're stuck in kernel space without context
* switches for an entirely unreasonable amount of time.
*/
resched_cpu(smp_processor_id());
}
static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)

1
kernel/sched/Makefile
View File

@ -12,6 +12,7 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
endif
obj-y += core.o proc.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
obj-y += wait.o completion.o
obj-$(CONFIG_SMP) += cpupri.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o

299
kernel/sched/completion.c Normal file
View File

@ -0,0 +1,299 @@
/*
* Generic wait-for-completion handler;
*
* It differs from semaphores in that their default case is the opposite,
* wait_for_completion default blocks whereas semaphore default non-block. The
* interface also makes it easy to 'complete' multiple waiting threads,
* something which isn't entirely natural for semaphores.
*
* But more importantly, the primitive documents the usage. Semaphores would
* typically be used for exclusion which gives rise to priority inversion.
* Waiting for completion is a typically sync point, but not an exclusion point.
*/
#include <linux/sched.h>
#include <linux/completion.h>
/**
* complete: - signals a single thread waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up a single thread waiting on this completion. Threads will be
* awakened in the same order in which they were queued.
*
* See also complete_all(), wait_for_completion() and related routines.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void complete(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
__wake_up_locked(&x->wait, TASK_NORMAL, 1);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
/**
* complete_all: - signals all threads waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up all threads waiting on this particular completion event.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void complete_all(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
__wake_up_locked(&x->wait, TASK_NORMAL, 0);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
static inline long __sched
do_wait_for_common(struct completion *x,
long (*action)(long), long timeout, int state)
{
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
__add_wait_queue_tail_exclusive(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
break;
}
__set_current_state(state);
spin_unlock_irq(&x->wait.lock);
timeout = action(timeout);
spin_lock_irq(&x->wait.lock);
} while (!x->done && timeout);
__remove_wait_queue(&x->wait, &wait);
if (!x->done)
return timeout;
}
x->done--;
return timeout ?: 1;
}
static inline long __sched
__wait_for_common(struct completion *x,
long (*action)(long), long timeout, int state)
{
might_sleep();
spin_lock_irq(&x->wait.lock);
timeout = do_wait_for_common(x, action, timeout, state);
spin_unlock_irq(&x->wait.lock);
return timeout;
}
static long __sched
wait_for_common(struct completion *x, long timeout, int state)
{
return __wait_for_common(x, schedule_timeout, timeout, state);
}
static long __sched
wait_for_common_io(struct completion *x, long timeout, int state)
{
return __wait_for_common(x, io_schedule_timeout, timeout, state);
}
/**
* wait_for_completion: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout.
*
* See also similar routines (i.e. wait_for_completion_timeout()) with timeout
* and interrupt capability. Also see complete().
*/
void __sched wait_for_completion(struct completion *x)
{
wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion);
/**
* wait_for_completion_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible.
*
* Return: 0 if timed out, and positive (at least 1, or number of jiffies left
* till timeout) if completed.
*/
unsigned long __sched
wait_for_completion_timeout(struct completion *x, unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_timeout);
/**
* wait_for_completion_io: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout. The caller is accounted as waiting
* for IO.
*/
void __sched wait_for_completion_io(struct completion *x)
{
wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_io);
/**
* wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible. The caller is accounted as waiting for IO.
*
* Return: 0 if timed out, and positive (at least 1, or number of jiffies left
* till timeout) if completed.
*/
unsigned long __sched
wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
{
return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_io_timeout);
/**
* wait_for_completion_interruptible: - waits for completion of a task (w/intr)
* @x: holds the state of this particular completion
*
* This waits for completion of a specific task to be signaled. It is
* interruptible.
*
* Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
int __sched wait_for_completion_interruptible(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
if (t == -ERESTARTSYS)
return t;
return 0;
}
EXPORT_SYMBOL(wait_for_completion_interruptible);
/**
* wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. It is interruptible. The timeout is in jiffies.
*
* Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
* or number of jiffies left till timeout) if completed.
*/
long __sched
wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
/**
* wait_for_completion_killable: - waits for completion of a task (killable)
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It can be
* interrupted by a kill signal.
*
* Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
int __sched wait_for_completion_killable(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
if (t == -ERESTARTSYS)
return t;
return 0;
}
EXPORT_SYMBOL(wait_for_completion_killable);
/**
* wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be
* signaled or for a specified timeout to expire. It can be
* interrupted by a kill signal. The timeout is in jiffies.
*
* Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
* or number of jiffies left till timeout) if completed.
*/
long __sched
wait_for_completion_killable_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_KILLABLE);
}
EXPORT_SYMBOL(wait_for_completion_killable_timeout);
/**
* try_wait_for_completion - try to decrement a completion without blocking
* @x: completion structure
*
* Return: 0 if a decrement cannot be done without blocking
* 1 if a decrement succeeded.
*
* If a completion is being used as a counting completion,
* attempt to decrement the counter without blocking. This
* enables us to avoid waiting if the resource the completion
* is protecting is not available.
*/
bool try_wait_for_completion(struct completion *x)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
else
x->done--;
spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
/**
* completion_done - Test to see if a completion has any waiters
* @x: completion structure
*
* Return: 0 if there are waiters (wait_for_completion() in progress)
* 1 if there are no waiters.
*
*/
bool completion_done(struct completion *x)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(completion_done);

677
kernel/sched/core.c
View File

@ -513,12 +513,11 @@ static inline void init_hrtick(void)
* might also involve a cross-CPU call to trigger the scheduler on
* the target CPU.
*/
#ifdef CONFIG_SMP
void resched_task(struct task_struct *p)
{
int cpu;
assert_raw_spin_locked(&task_rq(p)->lock);
lockdep_assert_held(&task_rq(p)->lock);
if (test_tsk_need_resched(p))
return;
@ -526,8 +525,10 @@ void resched_task(struct task_struct *p)
set_tsk_need_resched(p);
cpu = task_cpu(p);
if (cpu == smp_processor_id())
if (cpu == smp_processor_id()) {
set_preempt_need_resched();
return;
}
/* NEED_RESCHED must be visible before we test polling */
smp_mb();
@ -546,6 +547,7 @@ void resched_cpu(int cpu)
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
#ifdef CONFIG_SMP
#ifdef CONFIG_NO_HZ_COMMON
/*
* In the semi idle case, use the nearest busy cpu for migrating timers
@ -693,12 +695,6 @@ void sched_avg_update(struct rq *rq)
}
}
#else /* !CONFIG_SMP */
void resched_task(struct task_struct *p)
{
assert_raw_spin_locked(&task_rq(p)->lock);
set_tsk_need_resched(p);
}
#endif /* CONFIG_SMP */
#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
@ -767,14 +763,14 @@ static void set_load_weight(struct task_struct *p)
static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
update_rq_clock(rq);
sched_info_queued(p);
sched_info_queued(rq, p);
p->sched_class->enqueue_task(rq, p, flags);
}
static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
update_rq_clock(rq);
sched_info_dequeued(p);
sched_info_dequeued(rq, p);
p->sched_class->dequeue_task(rq, p, flags);
}
@ -987,7 +983,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
* ttwu() will sort out the placement.
*/
WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
!(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
!(task_preempt_count(p) & PREEMPT_ACTIVE));
#ifdef CONFIG_LOCKDEP
/*
@ -1017,6 +1013,107 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
__set_task_cpu(p, new_cpu);
}
static void __migrate_swap_task(struct task_struct *p, int cpu)
{
if (p->on_rq) {
struct rq *src_rq, *dst_rq;
src_rq = task_rq(p);
dst_rq = cpu_rq(cpu);
deactivate_task(src_rq, p, 0);
set_task_cpu(p, cpu);
activate_task(dst_rq, p, 0);
check_preempt_curr(dst_rq, p, 0);
} else {
/*
* Task isn't running anymore; make it appear like we migrated
* it before it went to sleep. This means on wakeup we make the
* previous cpu our targer instead of where it really is.
*/
p->wake_cpu = cpu;
}
}
struct migration_swap_arg {
struct task_struct *src_task, *dst_task;
int src_cpu, dst_cpu;
};
static int migrate_swap_stop(void *data)
{
struct migration_swap_arg *arg = data;
struct rq *src_rq, *dst_rq;
int ret = -EAGAIN;
src_rq = cpu_rq(arg->src_cpu);
dst_rq = cpu_rq(arg->dst_cpu);
double_raw_lock(&arg->src_task->pi_lock,
&arg->dst_task->pi_lock);
double_rq_lock(src_rq, dst_rq);
if (task_cpu(arg->dst_task) != arg->dst_cpu)
goto unlock;
if (task_cpu(arg->src_task) != arg->src_cpu)
goto unlock;
if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task)))
goto unlock;
if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task)))
goto unlock;
__migrate_swap_task(arg->src_task, arg->dst_cpu);
__migrate_swap_task(arg->dst_task, arg->src_cpu);
ret = 0;
unlock:
double_rq_unlock(src_rq, dst_rq);
raw_spin_unlock(&arg->dst_task->pi_lock);
raw_spin_unlock(&arg->src_task->pi_lock);
return ret;
}
/*
* Cross migrate two tasks
*/
int migrate_swap(struct task_struct *cur, struct task_struct *p)
{
struct migration_swap_arg arg;
int ret = -EINVAL;
arg = (struct migration_swap_arg){
.src_task = cur,
.src_cpu = task_cpu(cur),
.dst_task = p,
.dst_cpu = task_cpu(p),
};
if (arg.src_cpu == arg.dst_cpu)
goto out;
/*
* These three tests are all lockless; this is OK since all of them
* will be re-checked with proper locks held further down the line.
*/
if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu))
goto out;
if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task)))
goto out;
if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task)))
goto out;
ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg);
out:
return ret;
}
struct migration_arg {
struct task_struct *task;
int dest_cpu;
@ -1236,9 +1333,9 @@ out:
* The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
*/
static inline
int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
{
int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags);
/*
* In order not to call set_task_cpu() on a blocking task we need
@ -1330,12 +1427,13 @@ ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
if (rq->idle_stamp) {
u64 delta = rq_clock(rq) - rq->idle_stamp;
u64 max = 2*sysctl_sched_migration_cost;
u64 max = 2*rq->max_idle_balance_cost;
if (delta > max)
update_avg(&rq->avg_idle, delta);
if (rq->avg_idle > max)
rq->avg_idle = max;
else
update_avg(&rq->avg_idle, delta);
rq->idle_stamp = 0;
}
#endif
@ -1396,6 +1494,14 @@ static void sched_ttwu_pending(void)
void scheduler_ipi(void)
{
/*
* Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
* TIF_NEED_RESCHED remotely (for the first time) will also send
* this IPI.
*/
if (tif_need_resched())
set_preempt_need_resched();
if (llist_empty(&this_rq()->wake_list)
&& !tick_nohz_full_cpu(smp_processor_id())
&& !got_nohz_idle_kick())
@ -1513,7 +1619,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
if (p->sched_class->task_waking)
p->sched_class->task_waking(p);
cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
if (task_cpu(p) != cpu) {
wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu);
@ -1595,7 +1701,7 @@ int wake_up_state(struct task_struct *p, unsigned int state)
*
* __sched_fork() is basic setup used by init_idle() too:
*/
static void __sched_fork(struct task_struct *p)
static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
{
p->on_rq = 0;
@ -1619,16 +1725,24 @@ static void __sched_fork(struct task_struct *p)
#ifdef CONFIG_NUMA_BALANCING
if (p->mm && atomic_read(&p->mm->mm_users) == 1) {
p->mm->numa_next_scan = jiffies;
p->mm->numa_next_reset = jiffies;
p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
p->mm->numa_scan_seq = 0;
}
if (clone_flags & CLONE_VM)
p->numa_preferred_nid = current->numa_preferred_nid;
else
p->numa_preferred_nid = -1;
p->node_stamp = 0ULL;
p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
p->numa_migrate_seq = p->mm ? p->mm->numa_scan_seq - 1 : 0;
p->numa_scan_period = sysctl_numa_balancing_scan_delay;
p->numa_work.next = &p->numa_work;
p->numa_faults = NULL;
p->numa_faults_buffer = NULL;
INIT_LIST_HEAD(&p->numa_entry);
p->numa_group = NULL;
#endif /* CONFIG_NUMA_BALANCING */
}
@ -1654,12 +1768,12 @@ void set_numabalancing_state(bool enabled)
/*
* fork()/clone()-time setup:
*/
void sched_fork(struct task_struct *p)
void sched_fork(unsigned long clone_flags, struct task_struct *p)
{
unsigned long flags;
int cpu = get_cpu();
__sched_fork(p);
__sched_fork(clone_flags, p);
/*
* We mark the process as running here. This guarantees that
* nobody will actually run it, and a signal or other external
@ -1717,10 +1831,7 @@ void sched_fork(struct task_struct *p)
#if defined(CONFIG_SMP)
p->on_cpu = 0;
#endif
#ifdef CONFIG_PREEMPT_COUNT
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
init_task_preempt_count(p);
#ifdef CONFIG_SMP
plist_node_init(&p->pushable_tasks, MAX_PRIO);
#endif
@ -1747,7 +1858,7 @@ void wake_up_new_task(struct task_struct *p)
* - cpus_allowed can change in the fork path
* - any previously selected cpu might disappear through hotplug
*/
set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0));
set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0));
#endif
/* Initialize new task's runnable average */
@ -1838,7 +1949,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
trace_sched_switch(prev, next);
sched_info_switch(prev, next);
sched_info_switch(rq, prev, next);
perf_event_task_sched_out(prev, next);
fire_sched_out_preempt_notifiers(prev, next);
prepare_lock_switch(rq, next);
@ -1890,6 +2001,8 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
if (mm)
mmdrop(mm);
if (unlikely(prev_state == TASK_DEAD)) {
task_numa_free(prev);
/*
* Remove function-return probe instances associated with this
* task and put them back on the free list.
@ -2073,7 +2186,7 @@ void sched_exec(void)
int dest_cpu;
raw_spin_lock_irqsave(&p->pi_lock, flags);
dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0);
dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0);
if (dest_cpu == smp_processor_id())
goto unlock;
@ -2215,7 +2328,7 @@ notrace unsigned long get_parent_ip(unsigned long addr)
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_PREEMPT_TRACER))
void __kprobes add_preempt_count(int val)
void __kprobes preempt_count_add(int val)
{
#ifdef CONFIG_DEBUG_PREEMPT
/*
@ -2224,7 +2337,7 @@ void __kprobes add_preempt_count(int val)
if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
return;
#endif
preempt_count() += val;
__preempt_count_add(val);
#ifdef CONFIG_DEBUG_PREEMPT
/*
* Spinlock count overflowing soon?
@ -2235,9 +2348,9 @@ void __kprobes add_preempt_count(int val)
if (preempt_count() == val)
trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
}
EXPORT_SYMBOL(add_preempt_count);
EXPORT_SYMBOL(preempt_count_add);
void __kprobes sub_preempt_count(int val)
void __kprobes preempt_count_sub(int val)
{
#ifdef CONFIG_DEBUG_PREEMPT
/*
@ -2255,9 +2368,9 @@ void __kprobes sub_preempt_count(int val)
if (preempt_count() == val)
trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
preempt_count() -= val;
__preempt_count_sub(val);
}
EXPORT_SYMBOL(sub_preempt_count);
EXPORT_SYMBOL(preempt_count_sub);
#endif
@ -2430,6 +2543,7 @@ need_resched:
put_prev_task(rq, prev);
next = pick_next_task(rq);
clear_tsk_need_resched(prev);
clear_preempt_need_resched();
rq->skip_clock_update = 0;
if (likely(prev != next)) {
@ -2520,9 +2634,9 @@ asmlinkage void __sched notrace preempt_schedule(void)
return;
do {
add_preempt_count_notrace(PREEMPT_ACTIVE);
__preempt_count_add(PREEMPT_ACTIVE);
__schedule();
sub_preempt_count_notrace(PREEMPT_ACTIVE);
__preempt_count_sub(PREEMPT_ACTIVE);
/*
* Check again in case we missed a preemption opportunity
@ -2541,20 +2655,19 @@ EXPORT_SYMBOL(preempt_schedule);
*/
asmlinkage void __sched preempt_schedule_irq(void)
{
struct thread_info *ti = current_thread_info();
enum ctx_state prev_state;
/* Catch callers which need to be fixed */
BUG_ON(ti->preempt_count || !irqs_disabled());
BUG_ON(preempt_count() || !irqs_disabled());
prev_state = exception_enter();
do {
add_preempt_count(PREEMPT_ACTIVE);
__preempt_count_add(PREEMPT_ACTIVE);
local_irq_enable();
__schedule();
local_irq_disable();
sub_preempt_count(PREEMPT_ACTIVE);
__preempt_count_sub(PREEMPT_ACTIVE);
/*
* Check again in case we missed a preemption opportunity
@ -2575,393 +2688,6 @@ int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
}
EXPORT_SYMBOL(default_wake_function);
/*
* The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
* wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
* number) then we wake all the non-exclusive tasks and one exclusive task.
*
* There are circumstances in which we can try to wake a task which has already
* started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, int wake_flags, void *key)
{
wait_queue_t *curr, *next;
list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
unsigned flags = curr->flags;
if (curr->func(curr, mode, wake_flags, key) &&
(flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
break;
}
}
/**
* __wake_up - wake up threads blocked on a waitqueue.
* @q: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: is directly passed to the wakeup function
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void __wake_up(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
spin_lock_irqsave(&q->lock, flags);
__wake_up_common(q, mode, nr_exclusive, 0, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(__wake_up);
/*
* Same as __wake_up but called with the spinlock in wait_queue_head_t held.
*/
void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
{
__wake_up_common(q, mode, nr, 0, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_locked);
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
{
__wake_up_common(q, mode, 1, 0, key);
}
EXPORT_SYMBOL_GPL(__wake_up_locked_key);
/**
* __wake_up_sync_key - wake up threads blocked on a waitqueue.
* @q: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: opaque value to be passed to wakeup targets
*
* The sync wakeup differs that the waker knows that it will schedule
* away soon, so while the target thread will be woken up, it will not
* be migrated to another CPU - ie. the two threads are 'synchronized'
* with each other. This can prevent needless bouncing between CPUs.
*
* On UP it can prevent extra preemption.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
int wake_flags = WF_SYNC;
if (unlikely(!q))
return;
if (unlikely(nr_exclusive != 1))
wake_flags = 0;
spin_lock_irqsave(&q->lock, flags);
__wake_up_common(q, mode, nr_exclusive, wake_flags, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL_GPL(__wake_up_sync_key);
/*
* __wake_up_sync - see __wake_up_sync_key()
*/
void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
{
__wake_up_sync_key(q, mode, nr_exclusive, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
/**
* complete: - signals a single thread waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up a single thread waiting on this completion. Threads will be
* awakened in the same order in which they were queued.
*
* See also complete_all(), wait_for_completion() and related routines.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void complete(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
__wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
/**
* complete_all: - signals all threads waiting on this completion
* @x: holds the state of this particular completion
*
* This will wake up all threads waiting on this particular completion event.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void complete_all(struct completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
__wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
static inline long __sched
do_wait_for_common(struct completion *x,
long (*action)(long), long timeout, int state)
{
if (!x->done) {
DECLARE_WAITQUEUE(wait, current);
__add_wait_queue_tail_exclusive(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
break;
}
__set_current_state(state);
spin_unlock_irq(&x->wait.lock);
timeout = action(timeout);
spin_lock_irq(&x->wait.lock);
} while (!x->done && timeout);
__remove_wait_queue(&x->wait, &wait);
if (!x->done)
return timeout;
}
x->done--;
return timeout ?: 1;
}
static inline long __sched
__wait_for_common(struct completion *x,
long (*action)(long), long timeout, int state)
{
might_sleep();
spin_lock_irq(&x->wait.lock);
timeout = do_wait_for_common(x, action, timeout, state);
spin_unlock_irq(&x->wait.lock);
return timeout;
}
static long __sched
wait_for_common(struct completion *x, long timeout, int state)
{
return __wait_for_common(x, schedule_timeout, timeout, state);
}
static long __sched
wait_for_common_io(struct completion *x, long timeout, int state)
{
return __wait_for_common(x, io_schedule_timeout, timeout, state);
}
/**
* wait_for_completion: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout.
*
* See also similar routines (i.e. wait_for_completion_timeout()) with timeout
* and interrupt capability. Also see complete().
*/
void __sched wait_for_completion(struct completion *x)
{
wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion);
/**
* wait_for_completion_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible.
*
* Return: 0 if timed out, and positive (at least 1, or number of jiffies left
* till timeout) if completed.
*/
unsigned long __sched
wait_for_completion_timeout(struct completion *x, unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_timeout);
/**
* wait_for_completion_io: - waits for completion of a task
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout. The caller is accounted as waiting
* for IO.
*/
void __sched wait_for_completion_io(struct completion *x)
{
wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_io);
/**
* wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible. The caller is accounted as waiting for IO.
*
* Return: 0 if timed out, and positive (at least 1, or number of jiffies left
* till timeout) if completed.
*/
unsigned long __sched
wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
{
return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_io_timeout);
/**
* wait_for_completion_interruptible: - waits for completion of a task (w/intr)
* @x: holds the state of this particular completion
*
* This waits for completion of a specific task to be signaled. It is
* interruptible.
*
* Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
int __sched wait_for_completion_interruptible(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
if (t == -ERESTARTSYS)
return t;
return 0;
}
EXPORT_SYMBOL(wait_for_completion_interruptible);
/**
* wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. It is interruptible. The timeout is in jiffies.
*
* Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
* or number of jiffies left till timeout) if completed.
*/
long __sched
wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
/**
* wait_for_completion_killable: - waits for completion of a task (killable)
* @x: holds the state of this particular completion
*
* This waits to be signaled for completion of a specific task. It can be
* interrupted by a kill signal.
*
* Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
int __sched wait_for_completion_killable(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
if (t == -ERESTARTSYS)
return t;
return 0;
}
EXPORT_SYMBOL(wait_for_completion_killable);
/**
* wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
* @x: holds the state of this particular completion
* @timeout: timeout value in jiffies
*
* This waits for either a completion of a specific task to be
* signaled or for a specified timeout to expire. It can be
* interrupted by a kill signal. The timeout is in jiffies.
*
* Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
* or number of jiffies left till timeout) if completed.
*/
long __sched
wait_for_completion_killable_timeout(struct completion *x,
unsigned long timeout)
{
return wait_for_common(x, timeout, TASK_KILLABLE);
}
EXPORT_SYMBOL(wait_for_completion_killable_timeout);
/**
* try_wait_for_completion - try to decrement a completion without blocking
* @x: completion structure
*
* Return: 0 if a decrement cannot be done without blocking
* 1 if a decrement succeeded.
*
* If a completion is being used as a counting completion,
* attempt to decrement the counter without blocking. This
* enables us to avoid waiting if the resource the completion
* is protecting is not available.
*/
bool try_wait_for_completion(struct completion *x)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
else
x->done--;
spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
/**
* completion_done - Test to see if a completion has any waiters
* @x: completion structure
*
* Return: 0 if there are waiters (wait_for_completion() in progress)
* 1 if there are no waiters.
*
*/
bool completion_done(struct completion *x)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(completion_done);
static long __sched
sleep_on_common(wait_queue_head_t *q, int state, long timeout)
{
@ -3598,13 +3324,11 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
struct task_struct *p;
int retval;
get_online_cpus();
rcu_read_lock();
p = find_process_by_pid(pid);
if (!p) {
rcu_read_unlock();
put_online_cpus();
return -ESRCH;
}
@ -3661,7 +3385,6 @@ out_free_cpus_allowed:
free_cpumask_var(cpus_allowed);
out_put_task:
put_task_struct(p);
put_online_cpus();
return retval;
}
@ -3706,7 +3429,6 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
unsigned long flags;
int retval;
get_online_cpus();
rcu_read_lock();
retval = -ESRCH;
@ -3719,12 +3441,11 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
goto out_unlock;
raw_spin_lock_irqsave(&p->pi_lock, flags);
cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
cpumask_and(mask, &p->cpus_allowed, cpu_active_mask);
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
out_unlock:
rcu_read_unlock();
put_online_cpus();
return retval;
}
@ -3794,16 +3515,11 @@ SYSCALL_DEFINE0(sched_yield)
return 0;
}
static inline int should_resched(void)
{
return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
}
static void __cond_resched(void)
{
add_preempt_count(PREEMPT_ACTIVE);
__preempt_count_add(PREEMPT_ACTIVE);
__schedule();
sub_preempt_count(PREEMPT_ACTIVE);
__preempt_count_sub(PREEMPT_ACTIVE);
}
int __sched _cond_resched(void)
@ -4186,7 +3902,7 @@ void init_idle(struct task_struct *idle, int cpu)
raw_spin_lock_irqsave(&rq->lock, flags);
__sched_fork(idle);
__sched_fork(0, idle);
idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
@ -4212,7 +3928,7 @@ void init_idle(struct task_struct *idle, int cpu)
raw_spin_unlock_irqrestore(&rq->lock, flags);
/* Set the preempt count _outside_ the spinlocks! */
task_thread_info(idle)->preempt_count = 0;
init_idle_preempt_count(idle, cpu);
/*
* The idle tasks have their own, simple scheduling class:
@ -4346,6 +4062,53 @@ fail:
return ret;
}
#ifdef CONFIG_NUMA_BALANCING
/* Migrate current task p to target_cpu */
int migrate_task_to(struct task_struct *p, int target_cpu)
{
struct migration_arg arg = { p, target_cpu };
int curr_cpu = task_cpu(p);
if (curr_cpu == target_cpu)
return 0;
if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p)))
return -EINVAL;
/* TODO: This is not properly updating schedstats */
return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg);
}
/*
* Requeue a task on a given node and accurately track the number of NUMA
* tasks on the runqueues
*/
void sched_setnuma(struct task_struct *p, int nid)
{
struct rq *rq;
unsigned long flags;
bool on_rq, running;
rq = task_rq_lock(p, &flags);
on_rq = p->on_rq;
running = task_current(rq, p);
if (on_rq)
dequeue_task(rq, p, 0);
if (running)
p->sched_class->put_prev_task(rq, p);
p->numa_preferred_nid = nid;
if (running)
p->sched_class->set_curr_task(rq);
if (on_rq)
enqueue_task(rq, p, 0);
task_rq_unlock(rq, p, &flags);
}
#endif
/*
* migration_cpu_stop - this will be executed by a highprio stopper thread
* and performs thread migration by bumping thread off CPU then
@ -5119,6 +4882,7 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu)
DEFINE_PER_CPU(struct sched_domain *, sd_llc);
DEFINE_PER_CPU(int, sd_llc_size);
DEFINE_PER_CPU(int, sd_llc_id);
DEFINE_PER_CPU(struct sched_domain *, sd_numa);
static void update_top_cache_domain(int cpu)
{
@ -5135,6 +4899,9 @@ static void update_top_cache_domain(int cpu)
rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
per_cpu(sd_llc_size, cpu) = size;
per_cpu(sd_llc_id, cpu) = id;
sd = lowest_flag_domain(cpu, SD_NUMA);
rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
}
/*
@ -5654,6 +5421,7 @@ sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
| 0*SD_SHARE_PKG_RESOURCES
| 1*SD_SERIALIZE
| 0*SD_PREFER_SIBLING
| 1*SD_NUMA
| sd_local_flags(level)
,
.last_balance = jiffies,
@ -6335,14 +6103,17 @@ void __init sched_init_smp(void)
sched_init_numa();
get_online_cpus();
/*
* There's no userspace yet to cause hotplug operations; hence all the
* cpu masks are stable and all blatant races in the below code cannot
* happen.
*/
mutex_lock(&sched_domains_mutex);
init_sched_domains(cpu_active_mask);
cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
if (cpumask_empty(non_isolated_cpus))
cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
mutex_unlock(&sched_domains_mutex);
put_online_cpus();
hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE);
hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
@ -6505,6 +6276,7 @@ void __init sched_init(void)
rq->online = 0;
rq->idle_stamp = 0;
rq->avg_idle = 2*sysctl_sched_migration_cost;
rq->max_idle_balance_cost = sysctl_sched_migration_cost;
INIT_LIST_HEAD(&rq->cfs_tasks);
@ -7277,7 +7049,12 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
runtime_enabled = quota != RUNTIME_INF;
runtime_was_enabled = cfs_b->quota != RUNTIME_INF;
account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled);
/*
* If we need to toggle cfs_bandwidth_used, off->on must occur
* before making related changes, and on->off must occur afterwards
*/
if (runtime_enabled && !runtime_was_enabled)
cfs_bandwidth_usage_inc();
raw_spin_lock_irq(&cfs_b->lock);
cfs_b->period = ns_to_ktime(period);
cfs_b->quota = quota;
@ -7303,6 +7080,8 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
unthrottle_cfs_rq(cfs_rq);
raw_spin_unlock_irq(&rq->lock);
}
if (runtime_was_enabled && !runtime_enabled)
cfs_bandwidth_usage_dec();
out_unlock:
mutex_unlock(&cfs_constraints_mutex);

68
kernel/sched/debug.c
View File

@ -15,6 +15,7 @@
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/utsname.h>
#include <linux/mempolicy.h>
#include "sched.h"
@ -137,6 +138,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
#endif
#ifdef CONFIG_NUMA_BALANCING
SEQ_printf(m, " %d", cpu_to_node(task_cpu(p)));
#endif
#ifdef CONFIG_CGROUP_SCHED
SEQ_printf(m, " %s", task_group_path(task_group(p)));
#endif
@ -159,7 +163,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, p) {
if (!p->on_rq || task_cpu(p) != rq_cpu)
if (task_cpu(p) != rq_cpu)
continue;
print_task(m, rq, p);
@ -225,6 +229,14 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
atomic_read(&cfs_rq->tg->runnable_avg));
#endif
#endif
#ifdef CONFIG_CFS_BANDWIDTH
SEQ_printf(m, " .%-30s: %d\n", "tg->cfs_bandwidth.timer_active",
cfs_rq->tg->cfs_bandwidth.timer_active);
SEQ_printf(m, " .%-30s: %d\n", "throttled",
cfs_rq->throttled);
SEQ_printf(m, " .%-30s: %d\n", "throttle_count",
cfs_rq->throttle_count);
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
print_cfs_group_stats(m, cpu, cfs_rq->tg);
@ -345,7 +357,7 @@ static void sched_debug_header(struct seq_file *m)
cpu_clk = local_clock();
local_irq_restore(flags);
SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n",
SEQ_printf(m, "Sched Debug Version: v0.11, %s %.*s\n",
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
@ -488,6 +500,56 @@ static int __init init_sched_debug_procfs(void)
__initcall(init_sched_debug_procfs);
#define __P(F) \
SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)F)
#define P(F) \
SEQ_printf(m, "%-45s:%21Ld\n", #F, (long long)p->F)
#define __PN(F) \
SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) \
SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
static void sched_show_numa(struct task_struct *p, struct seq_file *m)
{
#ifdef CONFIG_NUMA_BALANCING
struct mempolicy *pol;
int node, i;
if (p->mm)
P(mm->numa_scan_seq);
task_lock(p);
pol = p->mempolicy;
if (pol && !(pol->flags & MPOL_F_MORON))
pol = NULL;
mpol_get(pol);
task_unlock(p);
SEQ_printf(m, "numa_migrations, %ld\n", xchg(&p->numa_pages_migrated, 0));
for_each_online_node(node) {
for (i = 0; i < 2; i++) {
unsigned long nr_faults = -1;
int cpu_current, home_node;
if (p->numa_faults)
nr_faults = p->numa_faults[2*node + i];
cpu_current = !i ? (task_node(p) == node) :
(pol && node_isset(node, pol->v.nodes));
home_node = (p->numa_preferred_nid == node);
SEQ_printf(m, "numa_faults, %d, %d, %d, %d, %ld\n",
i, node, cpu_current, home_node, nr_faults);
}
}
mpol_put(pol);
#endif
}
void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
{
unsigned long nr_switches;
@ -591,6 +653,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
SEQ_printf(m, "%-45s:%21Ld\n",
"clock-delta", (long long)(t1-t0));
}
sched_show_numa(p, m);
}
void proc_sched_set_task(struct task_struct *p)

1365
kernel/sched/fair.c
View File

File diff suppressed because it is too large Load Diff

19
kernel/sched/features.h
View File

@ -63,10 +63,23 @@ SCHED_FEAT(LB_MIN, false)
/*
* Apply the automatic NUMA scheduling policy. Enabled automatically
* at runtime if running on a NUMA machine. Can be controlled via
* numa_balancing=. Allow PTE scanning to be forced on UMA machines
* for debugging the core machinery.
* numa_balancing=
*/
#ifdef CONFIG_NUMA_BALANCING
SCHED_FEAT(NUMA, false)
SCHED_FEAT(NUMA_FORCE, false)
/*
* NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a
* higher number of hinting faults are recorded during active load
* balancing.
*/
SCHED_FEAT(NUMA_FAVOUR_HIGHER, true)
/*
* NUMA_RESIST_LOWER will resist moving tasks towards nodes where a
* lower number of hinting faults have been recorded. As this has
* the potential to prevent a task ever migrating to a new node
* due to CPU overload it is disabled by default.
*/
SCHED_FEAT(NUMA_RESIST_LOWER, false)
#endif

2
kernel/sched/idle_task.c
View File

@ -9,7 +9,7 @@
#ifdef CONFIG_SMP
static int
select_task_rq_idle(struct task_struct *p, int sd_flag, int flags)
select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}

22
kernel/sched/rt.c
View File

@ -246,8 +246,10 @@ static inline void rt_set_overload(struct rq *rq)
* if we should look at the mask. It would be a shame
* if we looked at the mask, but the mask was not
* updated yet.
*
* Matched by the barrier in pull_rt_task().
*/
wmb();
smp_wmb();
atomic_inc(&rq->rd->rto_count);
}
@ -1169,13 +1171,10 @@ static void yield_task_rt(struct rq *rq)
static int find_lowest_rq(struct task_struct *task);
static int
select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
{
struct task_struct *curr;
struct rq *rq;
int cpu;
cpu = task_cpu(p);
if (p->nr_cpus_allowed == 1)
goto out;
@ -1213,8 +1212,7 @@ select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
*/
if (curr && unlikely(rt_task(curr)) &&
(curr->nr_cpus_allowed < 2 ||
curr->prio <= p->prio) &&
(p->nr_cpus_allowed > 1)) {
curr->prio <= p->prio)) {
int target = find_lowest_rq(p);
if (target != -1)
@ -1630,6 +1628,12 @@ static int pull_rt_task(struct rq *this_rq)
if (likely(!rt_overloaded(this_rq)))
return 0;
/*
* Match the barrier from rt_set_overloaded; this guarantees that if we
* see overloaded we must also see the rto_mask bit.
*/
smp_rmb();
for_each_cpu(cpu, this_rq->rd->rto_mask) {
if (this_cpu == cpu)
continue;
@ -1931,8 +1935,8 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
p->rt.time_slice = sched_rr_timeslice;
/*
* Requeue to the end of queue if we (and all of our ancestors) are the
* only element on the queue
* Requeue to the end of queue if we (and all of our ancestors) are not
* the only element on the queue
*/
for_each_sched_rt_entity(rt_se) {
if (rt_se->run_list.prev != rt_se->run_list.next) {

52
kernel/sched/sched.h
View File

@ -6,6 +6,7 @@
#include <linux/spinlock.h>
#include <linux/stop_machine.h>
#include <linux/tick.h>
#include <linux/slab.h>
#include "cpupri.h"
#include "cpuacct.h"
@ -408,6 +409,10 @@ struct rq {
* remote CPUs use both these fields when doing load calculation.
*/
unsigned int nr_running;
#ifdef CONFIG_NUMA_BALANCING
unsigned int nr_numa_running;
unsigned int nr_preferred_running;
#endif
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
unsigned long last_load_update_tick;
@ -476,6 +481,9 @@ struct rq {
u64 age_stamp;
u64 idle_stamp;
u64 avg_idle;
/* This is used to determine avg_idle's max value */
u64 max_idle_balance_cost;
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
@ -552,6 +560,12 @@ static inline u64 rq_clock_task(struct rq *rq)
return rq->clock_task;
}
#ifdef CONFIG_NUMA_BALANCING
extern void sched_setnuma(struct task_struct *p, int node);
extern int migrate_task_to(struct task_struct *p, int cpu);
extern int migrate_swap(struct task_struct *, struct task_struct *);
#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_SMP
#define rcu_dereference_check_sched_domain(p) \
@ -593,9 +607,22 @@ static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
return hsd;
}
static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
{
struct sched_domain *sd;
for_each_domain(cpu, sd) {
if (sd->flags & flag)
break;
}
return sd;
}
DECLARE_PER_CPU(struct sched_domain *, sd_llc);
DECLARE_PER_CPU(int, sd_llc_size);
DECLARE_PER_CPU(int, sd_llc_id);
DECLARE_PER_CPU(struct sched_domain *, sd_numa);
struct sched_group_power {
atomic_t ref;
@ -605,6 +632,7 @@ struct sched_group_power {
*/
unsigned int power, power_orig;
unsigned long next_update;
int imbalance; /* XXX unrelated to power but shared group state */
/*
* Number of busy cpus in this group.
*/
@ -719,6 +747,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
*/
smp_wmb();
task_thread_info(p)->cpu = cpu;
p->wake_cpu = cpu;
#endif
}
@ -974,7 +1003,7 @@ struct sched_class {
void (*put_prev_task) (struct rq *rq, struct task_struct *p);
#ifdef CONFIG_SMP
int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
@ -1220,6 +1249,24 @@ static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
}
static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
{
if (l1 > l2)
swap(l1, l2);
spin_lock(l1);
spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
}
static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
{
if (l1 > l2)
swap(l1, l2);
raw_spin_lock(l1);
raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
}
/*
* double_rq_lock - safely lock two runqueues
*
@ -1305,7 +1352,8 @@ extern void print_rt_stats(struct seq_file *m, int cpu);
extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
extern void account_cfs_bandwidth_used(int enabled, int was_enabled);
extern void cfs_bandwidth_usage_inc(void);
extern void cfs_bandwidth_usage_dec(void);
#ifdef CONFIG_NO_HZ_COMMON
enum rq_nohz_flag_bits {

46
kernel/sched/stats.h
View File

@ -59,9 +59,9 @@ static inline void sched_info_reset_dequeued(struct task_struct *t)
* from dequeue_task() to account for possible rq->clock skew across cpus. The
* delta taken on each cpu would annul the skew.
*/
static inline void sched_info_dequeued(struct task_struct *t)
static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
{
unsigned long long now = rq_clock(task_rq(t)), delta = 0;
unsigned long long now = rq_clock(rq), delta = 0;
if (unlikely(sched_info_on()))
if (t->sched_info.last_queued)
@ -69,7 +69,7 @@ static inline void sched_info_dequeued(struct task_struct *t)
sched_info_reset_dequeued(t);
t->sched_info.run_delay += delta;
rq_sched_info_dequeued(task_rq(t), delta);
rq_sched_info_dequeued(rq, delta);
}
/*
@ -77,9 +77,9 @@ static inline void sched_info_dequeued(struct task_struct *t)
* long it was waiting to run. We also note when it began so that we
* can keep stats on how long its timeslice is.
*/
static void sched_info_arrive(struct task_struct *t)
static void sched_info_arrive(struct rq *rq, struct task_struct *t)
{
unsigned long long now = rq_clock(task_rq(t)), delta = 0;
unsigned long long now = rq_clock(rq), delta = 0;
if (t->sched_info.last_queued)
delta = now - t->sched_info.last_queued;
@ -88,7 +88,7 @@ static void sched_info_arrive(struct task_struct *t)
t->sched_info.last_arrival = now;
t->sched_info.pcount++;
rq_sched_info_arrive(task_rq(t), delta);
rq_sched_info_arrive(rq, delta);
}
/*
@ -96,11 +96,11 @@ static void sched_info_arrive(struct task_struct *t)
* the timestamp if it is already not set. It's assumed that
* sched_info_dequeued() will clear that stamp when appropriate.
*/
static inline void sched_info_queued(struct task_struct *t)
static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
{
if (unlikely(sched_info_on()))
if (!t->sched_info.last_queued)
t->sched_info.last_queued = rq_clock(task_rq(t));
t->sched_info.last_queued = rq_clock(rq);
}
/*
@ -111,15 +111,15 @@ static inline void sched_info_queued(struct task_struct *t)
* sched_info_queued() to mark that it has now again started waiting on
* the runqueue.
*/
static inline void sched_info_depart(struct task_struct *t)
static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
{
unsigned long long delta = rq_clock(task_rq(t)) -
unsigned long long delta = rq_clock(rq) -
t->sched_info.last_arrival;
rq_sched_info_depart(task_rq(t), delta);
rq_sched_info_depart(rq, delta);
if (t->state == TASK_RUNNING)
sched_info_queued(t);
sched_info_queued(rq, t);
}
/*
@ -128,32 +128,34 @@ static inline void sched_info_depart(struct task_struct *t)
* the idle task.) We are only called when prev != next.
*/
static inline void
__sched_info_switch(struct task_struct *prev, struct task_struct *next)
__sched_info_switch(struct rq *rq,
struct task_struct *prev, struct task_struct *next)
{
struct rq *rq = task_rq(prev);
/*
* prev now departs the cpu. It's not interesting to record
* stats about how efficient we were at scheduling the idle
* process, however.
*/
if (prev != rq->idle)
sched_info_depart(prev);
sched_info_depart(rq, prev);
if (next != rq->idle)
sched_info_arrive(next);
sched_info_arrive(rq, next);
}
static inline void
sched_info_switch(struct task_struct *prev, struct task_struct *next)
sched_info_switch(struct rq *rq,
struct task_struct *prev, struct task_struct *next)
{
if (unlikely(sched_info_on()))
__sched_info_switch(prev, next);
__sched_info_switch(rq, prev, next);
}
#else
#define sched_info_queued(t) do { } while (0)
#define sched_info_queued(rq, t) do { } while (0)
#define sched_info_reset_dequeued(t) do { } while (0)
#define sched_info_dequeued(t) do { } while (0)
#define sched_info_switch(t, next) do { } while (0)
#define sched_info_dequeued(rq, t) do { } while (0)
#define sched_info_depart(rq, t) do { } while (0)
#define sched_info_arrive(rq, next) do { } while (0)
#define sched_info_switch(rq, t, next) do { } while (0)
#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
/*

2
kernel/sched/stop_task.c
View File

@ -11,7 +11,7 @@
#ifdef CONFIG_SMP
static int
select_task_rq_stop(struct task_struct *p, int sd_flag, int flags)
select_task_rq_stop(struct task_struct *p, int cpu, int sd_flag, int flags)
{
return task_cpu(p); /* stop tasks as never migrate */
}

127
kernel/wait.c → kernel/sched/wait.c
View File

@ -52,6 +52,109 @@ void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
EXPORT_SYMBOL(remove_wait_queue);
/*
* The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
* wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
* number) then we wake all the non-exclusive tasks and one exclusive task.
*
* There are circumstances in which we can try to wake a task which has already
* started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, int wake_flags, void *key)
{
wait_queue_t *curr, *next;
list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
unsigned flags = curr->flags;
if (curr->func(curr, mode, wake_flags, key) &&
(flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
break;
}
}
/**
* __wake_up - wake up threads blocked on a waitqueue.
* @q: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: is directly passed to the wakeup function
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void __wake_up(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
spin_lock_irqsave(&q->lock, flags);
__wake_up_common(q, mode, nr_exclusive, 0, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(__wake_up);
/*
* Same as __wake_up but called with the spinlock in wait_queue_head_t held.
*/
void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
{
__wake_up_common(q, mode, nr, 0, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_locked);
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
{
__wake_up_common(q, mode, 1, 0, key);
}
EXPORT_SYMBOL_GPL(__wake_up_locked_key);
/**
* __wake_up_sync_key - wake up threads blocked on a waitqueue.
* @q: the waitqueue
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: opaque value to be passed to wakeup targets
*
* The sync wakeup differs that the waker knows that it will schedule
* away soon, so while the target thread will be woken up, it will not
* be migrated to another CPU - ie. the two threads are 'synchronized'
* with each other. This can prevent needless bouncing between CPUs.
*
* On UP it can prevent extra preemption.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
*/
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
{
unsigned long flags;
int wake_flags = 1; /* XXX WF_SYNC */
if (unlikely(!q))
return;
if (unlikely(nr_exclusive != 1))
wake_flags = 0;
spin_lock_irqsave(&q->lock, flags);
__wake_up_common(q, mode, nr_exclusive, wake_flags, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL_GPL(__wake_up_sync_key);
/*
* __wake_up_sync - see __wake_up_sync_key()
*/
void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
{
__wake_up_sync_key(q, mode, nr_exclusive, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
/*
* Note: we use "set_current_state()" _after_ the wait-queue add,
* because we need a memory barrier there on SMP, so that any
@ -92,6 +195,30 @@ prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
}
EXPORT_SYMBOL(prepare_to_wait_exclusive);
long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state)
{
unsigned long flags;
if (signal_pending_state(state, current))
return -ERESTARTSYS;
wait->private = current;
wait->func = autoremove_wake_function;
spin_lock_irqsave(&q->lock, flags);
if (list_empty(&wait->task_list)) {
if (wait->flags & WQ_FLAG_EXCLUSIVE)
__add_wait_queue_tail(q, wait);
else
__add_wait_queue(q, wait);
}
set_current_state(state);
spin_unlock_irqrestore(&q->lock, flags);
return 0;
}
EXPORT_SYMBOL(prepare_to_wait_event);
/**
* finish_wait - clean up after waiting in a queue
* @q: waitqueue waited on

16
kernel/softirq.c
View File

@ -100,13 +100,13 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt)
raw_local_irq_save(flags);
/*
* The preempt tracer hooks into add_preempt_count and will break
* The preempt tracer hooks into preempt_count_add and will break
* lockdep because it calls back into lockdep after SOFTIRQ_OFFSET
* is set and before current->softirq_enabled is cleared.
* We must manually increment preempt_count here and manually
* call the trace_preempt_off later.
*/
preempt_count() += cnt;
__preempt_count_add(cnt);
/*
* Were softirqs turned off above:
*/
@ -120,7 +120,7 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt)
#else /* !CONFIG_TRACE_IRQFLAGS */
static inline void __local_bh_disable(unsigned long ip, unsigned int cnt)
{
add_preempt_count(cnt);
preempt_count_add(cnt);
barrier();
}
#endif /* CONFIG_TRACE_IRQFLAGS */
@ -139,7 +139,7 @@ static void __local_bh_enable(unsigned int cnt)
if (softirq_count() == cnt)
trace_softirqs_on(_RET_IP_);
sub_preempt_count(cnt);
preempt_count_sub(cnt);
}
/*
@ -169,12 +169,12 @@ static inline void _local_bh_enable_ip(unsigned long ip)
* Keep preemption disabled until we are done with
* softirq processing:
*/
sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1);
preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1);
if (unlikely(!in_interrupt() && local_softirq_pending()))
do_softirq();
dec_preempt_count();
preempt_count_dec();
#ifdef CONFIG_TRACE_IRQFLAGS
local_irq_enable();
#endif
@ -256,7 +256,7 @@ restart:
" exited with %08x?\n", vec_nr,
softirq_to_name[vec_nr], h->action,
prev_count, preempt_count());
preempt_count() = prev_count;
preempt_count_set(prev_count);
}
rcu_bh_qs(cpu);
@ -369,7 +369,7 @@ void irq_exit(void)
account_irq_exit_time(current);
trace_hardirq_exit();
sub_preempt_count(HARDIRQ_OFFSET);
preempt_count_sub(HARDIRQ_OFFSET);
if (!in_interrupt() && local_softirq_pending())
invoke_softirq();

288
kernel/stop_machine.c
View File

@ -115,6 +115,182 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
return done.executed ? done.ret : -ENOENT;
}
/* This controls the threads on each CPU. */
enum multi_stop_state {
/* Dummy starting state for thread. */
MULTI_STOP_NONE,
/* Awaiting everyone to be scheduled. */
MULTI_STOP_PREPARE,
/* Disable interrupts. */
MULTI_STOP_DISABLE_IRQ,
/* Run the function */
MULTI_STOP_RUN,
/* Exit */
MULTI_STOP_EXIT,
};
struct multi_stop_data {
int (*fn)(void *);
void *data;
/* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
unsigned int num_threads;
const struct cpumask *active_cpus;
enum multi_stop_state state;
atomic_t thread_ack;
};
static void set_state(struct multi_stop_data *msdata,
enum multi_stop_state newstate)
{
/* Reset ack counter. */
atomic_set(&msdata->thread_ack, msdata->num_threads);
smp_wmb();
msdata->state = newstate;
}
/* Last one to ack a state moves to the next state. */
static void ack_state(struct multi_stop_data *msdata)
{
if (atomic_dec_and_test(&msdata->thread_ack))
set_state(msdata, msdata->state + 1);
}
/* This is the cpu_stop function which stops the CPU. */
static int multi_cpu_stop(void *data)
{
struct multi_stop_data *msdata = data;
enum multi_stop_state curstate = MULTI_STOP_NONE;
int cpu = smp_processor_id(), err = 0;
unsigned long flags;
bool is_active;
/*
* When called from stop_machine_from_inactive_cpu(), irq might
* already be disabled. Save the state and restore it on exit.
*/
local_save_flags(flags);
if (!msdata->active_cpus)
is_active = cpu == cpumask_first(cpu_online_mask);
else
is_active = cpumask_test_cpu(cpu, msdata->active_cpus);
/* Simple state machine */
do {
/* Chill out and ensure we re-read multi_stop_state. */
cpu_relax();
if (msdata->state != curstate) {
curstate = msdata->state;
switch (curstate) {
case MULTI_STOP_DISABLE_IRQ:
local_irq_disable();
hard_irq_disable();
break;
case MULTI_STOP_RUN:
if (is_active)
err = msdata->fn(msdata->data);
break;
default:
break;
}
ack_state(msdata);
}
} while (curstate != MULTI_STOP_EXIT);
local_irq_restore(flags);
return err;
}
struct irq_cpu_stop_queue_work_info {
int cpu1;
int cpu2;
struct cpu_stop_work *work1;
struct cpu_stop_work *work2;
};
/*
* This function is always run with irqs and preemption disabled.
* This guarantees that both work1 and work2 get queued, before
* our local migrate thread gets the chance to preempt us.
*/
static void irq_cpu_stop_queue_work(void *arg)
{
struct irq_cpu_stop_queue_work_info *info = arg;
cpu_stop_queue_work(info->cpu1, info->work1);
cpu_stop_queue_work(info->cpu2, info->work2);
}
/**
* stop_two_cpus - stops two cpus
* @cpu1: the cpu to stop
* @cpu2: the other cpu to stop
* @fn: function to execute
* @arg: argument to @fn
*
* Stops both the current and specified CPU and runs @fn on one of them.
*
* returns when both are completed.
*/
int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *arg)
{
struct cpu_stop_done done;
struct cpu_stop_work work1, work2;
struct irq_cpu_stop_queue_work_info call_args;
struct multi_stop_data msdata;
preempt_disable();
msdata = (struct multi_stop_data){
.fn = fn,
.data = arg,
.num_threads = 2,
.active_cpus = cpumask_of(cpu1),
};
work1 = work2 = (struct cpu_stop_work){
.fn = multi_cpu_stop,
.arg = &msdata,
.done = &done
};
call_args = (struct irq_cpu_stop_queue_work_info){
.cpu1 = cpu1,
.cpu2 = cpu2,
.work1 = &work1,
.work2 = &work2,
};
cpu_stop_init_done(&done, 2);
set_state(&msdata, MULTI_STOP_PREPARE);
/*
* If we observe both CPUs active we know _cpu_down() cannot yet have
* queued its stop_machine works and therefore ours will get executed
* first. Or its not either one of our CPUs that's getting unplugged,
* in which case we don't care.
*
* This relies on the stopper workqueues to be FIFO.
*/
if (!cpu_active(cpu1) || !cpu_active(cpu2)) {
preempt_enable();
return -ENOENT;
}
/*
* Queuing needs to be done by the lowest numbered CPU, to ensure
* that works are always queued in the same order on every CPU.
* This prevents deadlocks.
*/
smp_call_function_single(min(cpu1, cpu2),
&irq_cpu_stop_queue_work,
&call_args, 0);
preempt_enable();
wait_for_completion(&done.completion);
return done.executed ? done.ret : -ENOENT;
}
/**
* stop_one_cpu_nowait - stop a cpu but don't wait for completion
* @cpu: cpu to stop
@ -359,98 +535,14 @@ early_initcall(cpu_stop_init);
#ifdef CONFIG_STOP_MACHINE
/* This controls the threads on each CPU. */
enum stopmachine_state {
/* Dummy starting state for thread. */
STOPMACHINE_NONE,
/* Awaiting everyone to be scheduled. */
STOPMACHINE_PREPARE,
/* Disable interrupts. */
STOPMACHINE_DISABLE_IRQ,
/* Run the function */
STOPMACHINE_RUN,
/* Exit */
STOPMACHINE_EXIT,
};
struct stop_machine_data {
int (*fn)(void *);
void *data;
/* Like num_online_cpus(), but hotplug cpu uses us, so we need this. */
unsigned int num_threads;
const struct cpumask *active_cpus;
enum stopmachine_state state;
atomic_t thread_ack;
};
static void set_state(struct stop_machine_data *smdata,
enum stopmachine_state newstate)
{
/* Reset ack counter. */
atomic_set(&smdata->thread_ack, smdata->num_threads);
smp_wmb();
smdata->state = newstate;
}
/* Last one to ack a state moves to the next state. */
static void ack_state(struct stop_machine_data *smdata)
{
if (atomic_dec_and_test(&smdata->thread_ack))
set_state(smdata, smdata->state + 1);
}
/* This is the cpu_stop function which stops the CPU. */
static int stop_machine_cpu_stop(void *data)
{
struct stop_machine_data *smdata = data;
enum stopmachine_state curstate = STOPMACHINE_NONE;
int cpu = smp_processor_id(), err = 0;
unsigned long flags;
bool is_active;
/*
* When called from stop_machine_from_inactive_cpu(), irq might
* already be disabled. Save the state and restore it on exit.
*/
local_save_flags(flags);
if (!smdata->active_cpus)
is_active = cpu == cpumask_first(cpu_online_mask);
else
is_active = cpumask_test_cpu(cpu, smdata->active_cpus);
/* Simple state machine */
do {
/* Chill out and ensure we re-read stopmachine_state. */
cpu_relax();
if (smdata->state != curstate) {
curstate = smdata->state;
switch (curstate) {
case STOPMACHINE_DISABLE_IRQ:
local_irq_disable();
hard_irq_disable();
break;
case STOPMACHINE_RUN:
if (is_active)
err = smdata->fn(smdata->data);
break;
default:
break;
}
ack_state(smdata);
}
} while (curstate != STOPMACHINE_EXIT);
local_irq_restore(flags);
return err;
}
int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
struct stop_machine_data smdata = { .fn = fn, .data = data,
.num_threads = num_online_cpus(),
.active_cpus = cpus };
struct multi_stop_data msdata = {
.fn = fn,
.data = data,
.num_threads = num_online_cpus(),
.active_cpus = cpus,
};
if (!stop_machine_initialized) {
/*
@ -461,7 +553,7 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
unsigned long flags;
int ret;
WARN_ON_ONCE(smdata.num_threads != 1);
WARN_ON_ONCE(msdata.num_threads != 1);
local_irq_save(flags);
hard_irq_disable();
@ -472,8 +564,8 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
}
/* Set the initial state and stop all online cpus. */
set_state(&smdata, STOPMACHINE_PREPARE);
return stop_cpus(cpu_online_mask, stop_machine_cpu_stop, &smdata);
set_state(&msdata, MULTI_STOP_PREPARE);
return stop_cpus(cpu_online_mask, multi_cpu_stop, &msdata);
}
int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
@ -513,25 +605,25 @@ EXPORT_SYMBOL_GPL(stop_machine);
int stop_machine_from_inactive_cpu(int (*fn)(void *), void *data,
const struct cpumask *cpus)
{
struct stop_machine_data smdata = { .fn = fn, .data = data,
struct multi_stop_data msdata = { .fn = fn, .data = data,
.active_cpus = cpus };
struct cpu_stop_done done;
int ret;
/* Local CPU must be inactive and CPU hotplug in progress. */
BUG_ON(cpu_active(raw_smp_processor_id()));
smdata.num_threads = num_active_cpus() + 1; /* +1 for local */
msdata.num_threads = num_active_cpus() + 1; /* +1 for local */
/* No proper task established and can't sleep - busy wait for lock. */
while (!mutex_trylock(&stop_cpus_mutex))
cpu_relax();
/* Schedule work on other CPUs and execute directly for local CPU */
set_state(&smdata, STOPMACHINE_PREPARE);
set_state(&msdata, MULTI_STOP_PREPARE);
cpu_stop_init_done(&done, num_active_cpus());
queue_stop_cpus_work(cpu_active_mask, stop_machine_cpu_stop, &smdata,
queue_stop_cpus_work(cpu_active_mask, multi_cpu_stop, &msdata,
&done);
ret = stop_machine_cpu_stop(&smdata);
ret = multi_cpu_stop(&msdata);
/* Busy wait for completion. */
while (!completion_done(&done.completion))

21
kernel/sysctl.c
View File

@ -370,13 +370,6 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "numa_balancing_scan_period_reset",
.data = &sysctl_numa_balancing_scan_period_reset,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "numa_balancing_scan_period_max_ms",
.data = &sysctl_numa_balancing_scan_period_max,
@ -391,6 +384,20 @@ static struct ctl_table kern_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "numa_balancing_settle_count",
.data = &sysctl_numa_balancing_settle_count,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "numa_balancing_migrate_deferred",
.data = &sysctl_numa_balancing_migrate_deferred,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#endif /* CONFIG_NUMA_BALANCING */
#endif /* CONFIG_SCHED_DEBUG */
{

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