Pull bitmap updates from Yury Norov:
- introduce for_each_set_bitrange()
- use find_first_*_bit() instead of find_next_*_bit() where possible
- unify for_each_bit() macros
* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
vsprintf: rework bitmap_list_string
lib: bitmap: add performance test for bitmap_print_to_pagebuf
bitmap: unify find_bit operations
mm/percpu: micro-optimize pcpu_is_populated()
Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
find: micro-optimize for_each_{set,clear}_bit()
include/linux: move for_each_bit() macros from bitops.h to find.h
cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
tools: sync tools/bitmap with mother linux
all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
cpumask: use find_first_and_bit()
lib: add find_first_and_bit()
arch: remove GENERIC_FIND_FIRST_BIT entirely
include: move find.h from asm_generic to linux
bitops: move find_bit_*_le functions from le.h to find.h
bitops: protect find_first_{,zero}_bit properly
find_bit API and bitmap API are closely related, but inclusion paths
are different - include/asm-generic and include/linux, correspondingly.
In the past it made a lot of troubles due to circular dependencies
and/or undefined symbols. Fix this by moving find.h under include/linux.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
The printk header file includes ratelimit_types.h for its __ratelimit()
based usage. It is required for the static initializer used in
printk_ratelimited(). It uses a raw_spinlock_t and includes the
spinlock_types.h.
PREEMPT_RT substitutes spinlock_t with a rtmutex based implementation and so
its spinlock_t implmentation (provided by spinlock_rt.h) includes rtmutex.h and
atomic.h which leads to recursive includes where defines are missing.
By including only the raw_spinlock_t defines it avoids the atomic.h
related includes at this stage.
An example on powerpc:
| CALL scripts/atomic/check-atomics.sh
|In file included from include/linux/bug.h:5,
| from include/linux/page-flags.h:10,
| from kernel/bounds.c:10:
|arch/powerpc/include/asm/page_32.h: In function âclear_pageâ:
|arch/powerpc/include/asm/bug.h:87:4: error: implicit declaration of function â=80=98__WARNâ=80=99 [-Werror=3Dimplicit-function-declaration]
| 87 | __WARN(); \
| | ^~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro âWARN_ONâ=99
| 48 | WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
| | ^~~~~~~
|arch/powerpc/include/asm/bug.h:58:17: error: invalid application of âsizeofâ=99 to incomplete type âstruct bug_entryâ=99
| 58 | "i" (sizeof(struct bug_entry)), \
| | ^~~~~~
|arch/powerpc/include/asm/bug.h:89:3: note: in expansion of macro âBUG_ENTRYâ=99
| 89 | BUG_ENTRY(PPC_TLNEI " %4, 0", \
| | ^~~~~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro âWARN_ONâ=99
| 48 | WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
| | ^~~~~~~
|In file included from arch/powerpc/include/asm/ptrace.h:298,
| from arch/powerpc/include/asm/hw_irq.h:12,
| from arch/powerpc/include/asm/irqflags.h:12,
| from include/linux/irqflags.h:16,
| from include/asm-generic/cmpxchg-local.h:6,
| from arch/powerpc/include/asm/cmpxchg.h:526,
| from arch/powerpc/include/asm/atomic.h:11,
| from include/linux/atomic.h:7,
| from include/linux/rwbase_rt.h:6,
| from include/linux/rwlock_types.h:55,
| from include/linux/spinlock_types.h:74,
| from include/linux/ratelimit_types.h:7,
| from include/linux/printk.h:10,
| from include/asm-generic/bug.h:22,
| from arch/powerpc/include/asm/bug.h:109,
| from include/linux/bug.h:5,
| from include/linux/page-flags.h:10,
| from kernel/bounds.c:10:
|include/linux/thread_info.h: In function â=80=98copy_overflowâ=80=99:
|include/linux/thread_info.h:210:2: error: implicit declaration of function â=80=98WARNâ=80=99 [-Werror=3Dimplicit-function-declaration]
| 210 | WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
| | ^~~~
The WARN / BUG include pulls in printk.h and then ptrace.h expects WARN
(from bug.h) which is not yet complete. Even hw_irq.h has WARN_ON()
statements.
On POWERPC64 there are missing atomic64 defines while building 32bit
VDSO:
| VDSO32C arch/powerpc/kernel/vdso32/vgettimeofday.o
|In file included from include/linux/atomic.h:80,
| from include/linux/rwbase_rt.h:6,
| from include/linux/rwlock_types.h:55,
| from include/linux/spinlock_types.h:74,
| from include/linux/ratelimit_types.h:7,
| from include/linux/printk.h:10,
| from include/linux/kernel.h:19,
| from arch/powerpc/include/asm/page.h:11,
| from arch/powerpc/include/asm/vdso/gettimeofday.h:5,
| from include/vdso/datapage.h:137,
| from lib/vdso/gettimeofday.c:5,
| from <command-line>:
|include/linux/atomic-arch-fallback.h: In function âarch_atomic64_incâ=99:
|include/linux/atomic-arch-fallback.h:1447:2: error: implicit declaration of function âarch_atomic64_addâ; did you mean âarch_atomic_addâ? [-Werror=3Dimpl
|icit-function-declaration]
| 1447 | arch_atomic64_add(1, v);
| | ^~~~~~~~~~~~~~~~~
| | arch_atomic_add
The generic fallback is not included, atomics itself are not used. If
kernel.h does not include printk.h then it comes later from the bug.h
include.
Allow asm/spinlock_types.h to be included from
linux/spinlock_types_raw.h.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211129174654.668506-12-bigeasy@linutronix.de
Pull asm-generic cleanup from Arnd Bergmann:
"This is a single cleanup from Peter Collingbourne, removing some dead
code"
* tag 'asm-generic-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
arch: remove unused function syscall_set_arguments()
Pull tracing updates from Steven Rostedt:
- kprobes: Restructured stack unwinder to show properly on x86 when a
stack dump happens from a kretprobe callback.
- Fix to bootconfig parsing
- Have tracefs allow owner and group permissions by default (only
denying others). There's been pressure to allow non root to tracefs
in a controlled fashion, and using groups is probably the safest.
- Bootconfig memory managament updates.
- Bootconfig clean up to have the tools directory be less dependent on
changes in the kernel tree.
- Allow perf to be traced by function tracer.
- Rewrite of function graph tracer to be a callback from the function
tracer instead of having its own trampoline (this change will happen
on an arch by arch basis, and currently only x86_64 implements it).
- Allow multiple direct trampolines (bpf hooks to functions) be batched
together in one synchronization.
- Allow histogram triggers to add variables that can perform
calculations against the event's fields.
- Use the linker to determine architecture callbacks from the ftrace
trampoline to allow for proper parameter prototypes and prevent
warnings from the compiler.
- Extend histogram triggers to key off of variables.
- Have trace recursion use bit magic to determine preempt context over
if branches.
- Have trace recursion disable preemption as all use cases do anyway.
- Added testing for verification of tracing utilities.
- Various small clean ups and fixes.
* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
tracing/histogram: Fix semicolon.cocci warnings
tracing/histogram: Fix documentation inline emphasis warning
tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
tracing: Show size of requested perf buffer
bootconfig: Initialize ret in xbc_parse_tree()
ftrace: do CPU checking after preemption disabled
ftrace: disable preemption when recursion locked
tracing/histogram: Document expression arithmetic and constants
tracing/histogram: Optimize division by a power of 2
tracing/histogram: Covert expr to const if both operands are constants
tracing/histogram: Simplify handling of .sym-offset in expressions
tracing: Fix operator precedence for hist triggers expression
tracing: Add division and multiplication support for hist triggers
tracing: Add support for creating hist trigger variables from literal
selftests/ftrace: Stop tracing while reading the trace file by default
MAINTAINERS: Update KPROBES and TRACING entries
test_kprobes: Move it from kernel/ to lib/
docs, kprobes: Remove invalid URL and add new reference
samples/kretprobes: Fix return value if register_kretprobe() failed
lib/bootconfig: Fix the xbc_get_info kerneldoc
...
Pull scheduler updates from Thomas Gleixner:
- Revert the printk format based wchan() symbol resolution as it can
leak the raw value in case that the symbol is not resolvable.
- Make wchan() more robust and work with all kind of unwinders by
enforcing that the task stays blocked while unwinding is in progress.
- Prevent sched_fork() from accessing an invalid sched_task_group
- Improve asymmetric packing logic
- Extend scheduler statistics to RT and DL scheduling classes and add
statistics for bandwith burst to the SCHED_FAIR class.
- Properly account SCHED_IDLE entities
- Prevent a potential deadlock when initial priority is assigned to a
newly created kthread. A recent change to plug a race between cpuset
and __sched_setscheduler() introduced a new lock dependency which is
now triggered. Break the lock dependency chain by moving the priority
assignment to the thread function.
- Fix the idle time reporting in /proc/uptime for NOHZ enabled systems.
- Improve idle balancing in general and especially for NOHZ enabled
systems.
- Provide proper interfaces for live patching so it does not have to
fiddle with scheduler internals.
- Add cluster aware scheduling support.
- A small set of tweaks for RT (irqwork, wait_task_inactive(), various
scheduler options and delaying mmdrop)
- The usual small tweaks and improvements all over the place
* tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
sched/fair: Cleanup newidle_balance
sched/fair: Remove sysctl_sched_migration_cost condition
sched/fair: Wait before decaying max_newidle_lb_cost
sched/fair: Skip update_blocked_averages if we are defering load balance
sched/fair: Account update_blocked_averages in newidle_balance cost
x86: Fix __get_wchan() for !STACKTRACE
sched,x86: Fix L2 cache mask
sched/core: Remove rq_relock()
sched: Improve wake_up_all_idle_cpus() take #2
irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT
irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT
irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.
sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ
sched: Add cluster scheduler level for x86
sched: Add cluster scheduler level in core and related Kconfig for ARM64
topology: Represent clusters of CPUs within a die
sched: Disable -Wunused-but-set-variable
sched: Add wrapper for get_wchan() to keep task blocked
x86: Fix get_wchan() to support the ORC unwinder
proc: Use task_is_running() for wchan in /proc/$pid/stat
...
Building csky:allmodconfig results in the following build error.
In file included from ./include/linux/bitops.h:33,
from ./include/linux/log2.h:12,
from kernel/bounds.c:13:
./arch/csky/include/asm/bitops.h:77: error: "__clear_bit" redefined
Since commit 9248e52fec ("locking/atomic: simplify non-atomic wrappers"),
__clear_bit is defined in include/asm-generic/bitops/non-atomic.h,
and the define in the csky include file is no longer necessary or useful.
Remove it.
Fixes: 9248e52fec ("locking/atomic: simplify non-atomic wrappers")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guo Ren <guoren@kernel.org>
Remove the csky implemenation of strncpy/strnlen and instead use the
generic versions. The csky version is fairly slow because it always does
byte accesses even for aligned data, and it lacks a checks for
user_addr_max().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This is a preparation for changing over architectures to the
generic implementation one at a time. As there are no callers
of either __strncpy_from_user() or __strnlen_user(), fold these
into the strncpy_from_user() and strnlen_user() functions to make
each implementation independent of the others.
Many of these implementations have known bugs, but the intention
here is to not change behavior at all and stay compatible with
those bugs for the moment.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
We'd like all architectures to convert to ARCH_ATOMIC, as once all
architectures are converted it will be possible to make significant
cleanups to the atomics headers, and this will make it much easier to
generically enable atomic functionality (e.g. debug logic in the
instrumented wrappers).
As a step towards that, this patch migrates csky to ARCH_ATOMIC. The
arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common
code wraps these with optional instrumentation to provide the regular
functions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Guo Ren <guoren@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-17-mark.rutland@arm.com
: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
It could help to reduce the latency of the time-related functions
in user space.
We have referenced arm's and riscv's implementation for the patch.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Vincent Chen <vincent.chen@sifive.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Current csky's swappon is broken by wrong swap PTE entry format.
Now redesign the new format for abiv1 & abiv2 and make swappon +
zram work properly on csky machines.
C-SKY PTE has VALID, DIRTY to emulate PRESENT, READ, WRITE, EXEC
attributes. GLOBAL bit is shared by two pages in the same tlb
entry. So we need to keep GLOBAL, VALID, PRESENT zero in swp_pte.
To distinguish PAGE_NONE and swp_pte, we need to use an additional
bit (abiv1 is _PAGE_READ, abiv2 is _PAGE_WRITE).
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
When the system memory is exhausted, linux will trigger kswapd to
shrink memory page cache. We found the csky's .text file mapping
pages would be reclaimed earlier than arm's elf. Because csky
doesn't give _PAGE_ACCESSED for default pgprot and in zap_pte_range
if (pte_young(ptent) &&
likely(!(vma->vm_flags & VM_SEQ_READ)))
mark_page_accessed(page);
mark_page_accessed will put the pages into active lru list.
[ 3.652722] delete busybox page from inactive file list
Call Trace:
[<9012a376>] dump_stack+0xe/0x24
[<9012a370>] dump_stack+0x8/0x24
[<9005b780>] activate_page+0x2b4/0x2d4
[<90132502>] vsnprintf+0x2c6/0x374
[<9005b880>] mark_page_accessed+0xe0/0x150
[<9006903e>] unmap_page_range+0x166/0x33c
[<90021844>] get_signal+0x98/0x3b4
[<90069232>] unmap_single_vma+0x1e/0x24
[<90069462>] unmap_vmas+0x26/0x40
[<9006d3d8>] exit_mmap+0x60/0xbc
[<9006a140>] handle_mm_fault+0x700/0xcec
[<900426b2>] ktime_get_with_offset+0x86/0x130
[<90017566>] mmput+0x2e/0x90
[<9001a30a>] do_exit+0x13e/0x6f0
[<90015448>] page_fault_end+0x14/0x74
[<9001b4bc>] SyS_exit_group+0x0/0xc
[<9001b47c>] do_group_exit+0x2c/0x6c
[<9001b4c8>] __wake_up_parent+0x0/0x20
[<9001399e>] csky_systemcall+0x6e/0x72
csky will throw the pages at first and keep them in active lru
list later after real accessed, but arm would keep them in active
lru list at the beginning.
The following are statistics of different architecture styles:
Default _PAGE_ACCESSED: alpha, arm, arm64, ia64, m68k, microblaze,
openrisc, powerpc, riscv, sh, um, x86,
xtensa
Not def _PAGE_ACCESSED: arc, c6x, h8300, hexgon, mips, s390, nds32,
nios2, parisc, sparc
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Xu Kai <xukai@nationalchip.com>
Signed-off-by: Xu Kai <xukai@nationalchip.com>
Reconstruct vdso framework to support future vsyscall,
vgettimeofday features. These are very important features to reduce
system calls into the kernel for performance improvement.
The patch is reference RISC-V's
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Sync arch/riscv/mm/fault.c into arch/csky for easy maintenance.
Here are the patches related to the modification:
cac4d1d "riscv/mm/fault: Move no context handling to no_context()"
ac416a7 "riscv/mm/fault: Move vmalloc fault handling to vmalloc_fault()"
6c11ffb "riscv/mm/fault: Move fault error handling to mm_fault_error()"
afb8c6f "riscv/mm/fault: Move access error check to function"
bda281d "riscv/mm/fault: Simplify fault error handling"
a51271d "riscv/mm/fault: Move bad area handling to bad_area()"
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
TLB invalidate didn't contain a barrier operation in csky cpu and
we need to prevent previous PTW response after TLB invalidation
instruction. Of cause, the ASID changing also needs to take care
of the issue.
CPU0 CPU1
=============== ===============
set_pte
sync_is() -> See the previous set_pte for all harts
tlbi.vas -> Invalidate all harts TLB entry & flush pipeline
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Fixup commit c2d1adfa9a24 "csky: Add memory layout 2.5G(user):1.5G
(kernel)". That patch broke the global bit in PTE.
C-SKY TLB's entry contain two pages:
vpn, vpn + 1 -> ppn0, ppn1
All PPN's attributes contain global bit and final global is PPN0.G
& PPN1.G. So we must keep PPN0.G and PPN1.G same in one TLB's
entry.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Arnd said:
I would guess that for csky, this is a mistake, as the architecture
is fairly new and should be able to implement it.
Guo reply:
The c610, c807, c810 don't support SMP, so futex_cmpxchg_enabled = 1
with asm-generic's implementation.
For c860, there is no HAVE_FUTEX_CMPXCHG and cmpxchg_inatomic/inuser
implementation, so futex_cmpxchg_enabled = 0.
Thx for point it out, we'll implement cmpxchg_inatomic/inuser for
C860 and still use asm-generic for non-smp CPUs.
LTP test:
futex_wait01 1 TPASS : futex_wait(): errno=ETIMEDOUT(110): Connection timed out
futex_wait01 2 TPASS : futex_wait(): errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable
futex_wait01 3 TPASS : futex_wait(): errno=ETIMEDOUT(110): Connection timed out
futex_wait01 4 TPASS : futex_wait(): errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable
futex_wait02 1 TPASS : futex_wait() woken up
futex_wait03 1 TPASS : futex_wait() woken up
futex_wait04 1 TPASS : futex_wait() returned -1: errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/lkml/CAK8P3a3+WaQNyJ6Za2qfu6=0mBgU1hApnRXrdp1b1=P7wwyRUg@mail.gmail.com/
Remove shareable bit for ordering barrier, just keep ordering
in current hart is enough for SMP. Using three continuous
sync.is as PTW barrier to prevent speculative PTW in 860
microarchitecture.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
There are two ways for translating va to pa for csky:
- Use TLB(Translate Lookup Buffer) and PTW (Page Table Walk)
- Use SSEG0/1 (Simple Segment Mapping)
We use tlb mapping 0-2G and 3G-4G virtual address area and SSEG0/1
are for 2G-2.5G and 2.5G-3G translation. We could disable SSEG0
to use 2G-2.5G as TLB user mapping.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe:
"This sits on top of of the core entry/exit and x86 entry branch from
the tip tree, which contains the generic and x86 parts of this work.
Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL.
With that done, we can get rid of JOBCTL_TASK_WORK from task_work and
signal.c, and also remove a deadlock work-around in io_uring around
knowing that signal based task_work waking is invoked with the sighand
wait queue head lock.
The motivation for this work is to decouple signal notify based
task_work, of which io_uring is a heavy user of, from sighand. The
sighand lock becomes a huge contention point, particularly for
threaded workloads where it's shared between threads. Even outside of
threaded applications it's slower than it needs to be.
Roman Gershman <romger@amazon.com> reported that his networked
workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU
after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all
spent hammering on the sighand lock, showing 57% of the CPU time there
[1].
There are further cleanups possible on top of this. One example is
TIF_PATCH_PENDING, where a patch already exists to use
TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more
consolidation, but the work stands on its own as well"
[1] https://github.com/axboe/liburing/issues/215
* tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits)
io_uring: remove 'twa_signal_ok' deadlock work-around
kernel: remove checking for TIF_NOTIFY_SIGNAL
signal: kill JOBCTL_TASK_WORK
io_uring: JOBCTL_TASK_WORK is no longer used by task_work
task_work: remove legacy TWA_SIGNAL path
sparc: add support for TIF_NOTIFY_SIGNAL
riscv: add support for TIF_NOTIFY_SIGNAL
nds32: add support for TIF_NOTIFY_SIGNAL
ia64: add support for TIF_NOTIFY_SIGNAL
h8300: add support for TIF_NOTIFY_SIGNAL
c6x: add support for TIF_NOTIFY_SIGNAL
alpha: add support for TIF_NOTIFY_SIGNAL
xtensa: add support for TIF_NOTIFY_SIGNAL
arm: add support for TIF_NOTIFY_SIGNAL
microblaze: add support for TIF_NOTIFY_SIGNAL
hexagon: add support for TIF_NOTIFY_SIGNAL
csky: add support for TIF_NOTIFY_SIGNAL
openrisc: add support for TIF_NOTIFY_SIGNAL
sh: add support for TIF_NOTIFY_SIGNAL
um: add support for TIF_NOTIFY_SIGNAL
...
Pull asm-generic mmu-context cleanup from Arnd Bergmann:
"This is a cleanup series from Nicholas Piggin, preparing for later
changes. The asm/mmu_context.h header are generalized and common code
moved to asm-gneneric/mmu_context.h.
This saves a bit of code and makes it easier to change in the future"
* tag 'asm-generic-mmu-context-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (25 commits)
h8300: Fix generic mmu_context build
m68k: mmu_context: Fix Sun-3 build
xtensa: use asm-generic/mmu_context.h for no-op implementations
x86: use asm-generic/mmu_context.h for no-op implementations
um: use asm-generic/mmu_context.h for no-op implementations
sparc: use asm-generic/mmu_context.h for no-op implementations
sh: use asm-generic/mmu_context.h for no-op implementations
s390: use asm-generic/mmu_context.h for no-op implementations
riscv: use asm-generic/mmu_context.h for no-op implementations
powerpc: use asm-generic/mmu_context.h for no-op implementations
parisc: use asm-generic/mmu_context.h for no-op implementations
openrisc: use asm-generic/mmu_context.h for no-op implementations
nios2: use asm-generic/mmu_context.h for no-op implementations
nds32: use asm-generic/mmu_context.h for no-op implementations
mips: use asm-generic/mmu_context.h for no-op implementations
microblaze: use asm-generic/mmu_context.h for no-op implementations
m68k: use asm-generic/mmu_context.h for no-op implementations
ia64: use asm-generic/mmu_context.h for no-op implementations
hexagon: use asm-generic/mmu_context.h for no-op implementations
csky: use asm-generic/mmu_context.h for no-op implementations
...
Pull regset updates from Al Viro:
"Dead code removal, mostly.
The only exception is a bit of cleanups on itanic (getting rid of
redundant stack unwinds - each access_uarea() call does it and we call
that 7 times in a row in ptrace_[sg]etregs(), *after* having done it
ourselves in the caller; location where the user registers have been
spilled won't change under us, and we can bloody well just call
access_elf_reg() directly, giving it the unw_frame_info we'd
calculated for our own purposes)"
* 'regset.followup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
c6x: kill ELF_CORE_COPY_FPREGS
whack-a-mole: USE_ELF_CORE_DUMP
[ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea()
[ia64] missed cleanups from switch to regset coredumps
arm: kill dump_task_regs()
