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Merge branch 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into pm-freezer

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* 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits)
  freezer: fix wait_event_freezable/__thaw_task races
  freezer: kill unused set_freezable_with_signal()
  dmatest: don't use set_freezable_with_signal()
  usb_storage: don't use set_freezable_with_signal()
  freezer: remove unused @sig_only from freeze_task()
  freezer: use lock_task_sighand() in fake_signal_wake_up()
  freezer: restructure __refrigerator()
  freezer: fix set_freezable[_with_signal]() race
  freezer: remove should_send_signal() and update frozen()
  freezer: remove now unused TIF_FREEZE
  freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE
  cgroup_freezer: prepare for removal of TIF_FREEZE
  freezer: clean up freeze_processes() failure path
  freezer: kill PF_FREEZING
  freezer: test freezable conditions while holding freezer_lock
  freezer: make freezing indicate freeze condition in effect
  freezer: use dedicated lock instead of task_lock() + memory barrier
  freezer: don't distinguish nosig tasks on thaw
  freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks
  freezer: rename thaw_process() to __thaw_task() and simplify the implementation
  ...
This commit is contained in:
Rafael J. Wysocki 2011-11-23 21:09:02 +01:00
commit 986b11c3ee
57 changed files with 310 additions and 408 deletions
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14
Documentation/power/freezing-of-tasks.txt
View File

@ -21,7 +21,7 @@ freeze_processes() (defined in kernel/power/process.c) is called. It executes
try_to_freeze_tasks() that sets TIF_FREEZE for all of the freezable tasks and
either wakes them up, if they are kernel threads, or sends fake signals to them,
if they are user space processes. A task that has TIF_FREEZE set, should react
to it by calling the function called refrigerator() (defined in
to it by calling the function called __refrigerator() (defined in
kernel/freezer.c), which sets the task's PF_FROZEN flag, changes its state
to TASK_UNINTERRUPTIBLE and makes it loop until PF_FROZEN is cleared for it.
Then, we say that the task is 'frozen' and therefore the set of functions
@ -29,10 +29,10 @@ handling this mechanism is referred to as 'the freezer' (these functions are
defined in kernel/power/process.c, kernel/freezer.c & include/linux/freezer.h).
User space processes are generally frozen before kernel threads.
It is not recommended to call refrigerator() directly. Instead, it is
recommended to use the try_to_freeze() function (defined in
include/linux/freezer.h), that checks the task's TIF_FREEZE flag and makes the
task enter refrigerator() if the flag is set.
__refrigerator() must not be called directly. Instead, use the
try_to_freeze() function (defined in include/linux/freezer.h), that checks
the task's TIF_FREEZE flag and makes the task enter __refrigerator() if the
flag is set.
For user space processes try_to_freeze() is called automatically from the
signal-handling code, but the freezable kernel threads need to call it
@ -61,13 +61,13 @@ wait_event_freezable() and wait_event_freezable_timeout() macros.
After the system memory state has been restored from a hibernation image and
devices have been reinitialized, the function thaw_processes() is called in
order to clear the PF_FROZEN flag for each frozen task. Then, the tasks that
have been frozen leave refrigerator() and continue running.
have been frozen leave __refrigerator() and continue running.
III. Which kernel threads are freezable?
Kernel threads are not freezable by default. However, a kernel thread may clear
PF_NOFREEZE for itself by calling set_freezable() (the resetting of PF_NOFREEZE
directly is strongly discouraged). From this point it is regarded as freezable
directly is not allowed). From this point it is regarded as freezable
and must call try_to_freeze() in a suitable place.
IV. Why do we do that?

2
arch/alpha/include/asm/thread_info.h
View File

@ -79,7 +79,6 @@ register struct thread_info *__current_thread_info __asm__("$8");
#define TIF_UAC_SIGBUS 12 /* ! userspace part of 'osf_sysinfo' */
#define TIF_MEMDIE 13 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 14 /* restore signal mask in do_signal */
#define TIF_FREEZE 16 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
@ -87,7 +86,6 @@ register struct thread_info *__current_thread_info __asm__("$8");
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_FREEZE (1<<TIF_FREEZE)
/* Work to do on interrupt/exception return. */
#define _TIF_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \

2
arch/arm/include/asm/thread_info.h
View File

@ -142,7 +142,6 @@ extern void vfp_flush_hwstate(struct thread_info *);
#define TIF_POLLING_NRFLAG 16
#define TIF_USING_IWMMXT 17
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19
#define TIF_RESTORE_SIGMASK 20
#define TIF_SECCOMP 21
@ -152,7 +151,6 @@ extern void vfp_flush_hwstate(struct thread_info *);
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)

2
arch/avr32/include/asm/thread_info.h
View File

@ -85,7 +85,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_RESTORE_SIGMASK 7 /* restore signal mask in do_signal */
#define TIF_CPU_GOING_TO_SLEEP 8 /* CPU is entering sleep 0 mode */
#define TIF_NOTIFY_RESUME 9 /* callback before returning to user */
#define TIF_FREEZE 29
#define TIF_DEBUG 30 /* debugging enabled */
#define TIF_USERSPACE 31 /* true if FS sets userspace */
@ -98,7 +97,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_CPU_GOING_TO_SLEEP (1 << TIF_CPU_GOING_TO_SLEEP)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_FREEZE (1 << TIF_FREEZE)
/* Note: The masks below must never span more than 16 bits! */

2
arch/blackfin/include/asm/thread_info.h
View File

@ -100,7 +100,6 @@ static inline struct thread_info *current_thread_info(void)
TIF_NEED_RESCHED */
#define TIF_MEMDIE 4 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
#define TIF_FREEZE 6 /* is freezing for suspend */
#define TIF_IRQ_SYNC 7 /* sync pipeline stage */
#define TIF_NOTIFY_RESUME 8 /* callback before returning to user */
#define TIF_SINGLESTEP 9
@ -111,7 +110,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_IRQ_SYNC (1<<TIF_IRQ_SYNC)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)

2
arch/cris/include/asm/thread_info.h
View File

@ -86,7 +86,6 @@ struct thread_info {
#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
#define TIF_FREEZE 18 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
@ -94,7 +93,6 @@ struct thread_info {
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */

2
arch/frv/include/asm/thread_info.h
View File

@ -111,7 +111,6 @@ register struct thread_info *__current_thread_info asm("gr15");
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
#define TIF_FREEZE 18 /* freezing for suspend */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
@ -120,7 +119,6 @@ register struct thread_info *__current_thread_info asm("gr15");
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */

2
arch/h8300/include/asm/thread_info.h
View File

@ -90,7 +90,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_MEMDIE 4 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
#define TIF_NOTIFY_RESUME 6 /* callback before returning to user */
#define TIF_FREEZE 16 /* is freezing for suspend */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@ -99,7 +98,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */

2
arch/ia64/include/asm/thread_info.h
View File

@ -113,7 +113,6 @@ struct thread_info {
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
#define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */
#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */
#define TIF_FREEZE 20 /* is freezing for suspend */
#define TIF_RESTORE_RSE 21 /* user RBS is newer than kernel RBS */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
@ -126,7 +125,6 @@ struct thread_info {
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_MCA_INIT (1 << TIF_MCA_INIT)
#define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_RESTORE_RSE (1 << TIF_RESTORE_RSE)
/* "work to do on user-return" bits */

2
arch/m32r/include/asm/thread_info.h
View File

@ -138,7 +138,6 @@ static inline unsigned int get_thread_fault_code(void)
#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
@ -149,7 +148,6 @@ static inline unsigned int get_thread_fault_code(void)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */

1
arch/m68k/include/asm/thread_info.h
View File

@ -103,7 +103,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_DELAYED_TRACE 14 /* single step a syscall */
#define TIF_SYSCALL_TRACE 15 /* syscall trace active */
#define TIF_MEMDIE 16 /* is terminating due to OOM killer */
#define TIF_FREEZE 17 /* thread is freezing for suspend */
#define TIF_RESTORE_SIGMASK 18 /* restore signal mask in do_signal */
#endif /* _ASM_M68K_THREAD_INFO_H */

2
arch/microblaze/include/asm/thread_info.h
View File

@ -125,7 +125,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_MEMDIE 6 /* is terminating due to OOM killer */
#define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */
#define TIF_SECCOMP 10 /* secure computing */
#define TIF_FREEZE 14 /* Freezing for suspend */
/* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_POLLING_NRFLAG 16
@ -137,7 +136,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_IRET (1 << TIF_IRET)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)

2
arch/mips/include/asm/thread_info.h
View File

@ -117,7 +117,6 @@ register struct thread_info *__current_thread_info __asm__("$28");
#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19
#define TIF_FIXADE 20 /* Fix address errors in software */
#define TIF_LOGADE 21 /* Log address errors to syslog */
#define TIF_32BIT_REGS 22 /* also implies 16/32 fprs */
@ -141,7 +140,6 @@ register struct thread_info *__current_thread_info __asm__("$28");
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_FIXADE (1<<TIF_FIXADE)
#define _TIF_LOGADE (1<<TIF_LOGADE)
#define _TIF_32BIT_REGS (1<<TIF_32BIT_REGS)

2
arch/mn10300/include/asm/thread_info.h
View File

@ -165,7 +165,6 @@ extern void free_thread_info(struct thread_info *);
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
#define TIF_FREEZE 18 /* freezing for suspend */
#define _TIF_SYSCALL_TRACE +(1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME +(1 << TIF_NOTIFY_RESUME)
@ -174,7 +173,6 @@ extern void free_thread_info(struct thread_info *);
#define _TIF_SINGLESTEP +(1 << TIF_SINGLESTEP)
#define _TIF_RESTORE_SIGMASK +(1 << TIF_RESTORE_SIGMASK)
#define _TIF_POLLING_NRFLAG +(1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE +(1 << TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */

2
arch/parisc/include/asm/thread_info.h
View File

@ -58,7 +58,6 @@ struct thread_info {
#define TIF_32BIT 4 /* 32 bit binary */
#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 6 /* restore saved signal mask */
#define TIF_FREEZE 7 /* is freezing for suspend */
#define TIF_NOTIFY_RESUME 8 /* callback before returning to user */
#define TIF_SINGLESTEP 9 /* single stepping? */
#define TIF_BLOCKSTEP 10 /* branch stepping? */
@ -69,7 +68,6 @@ struct thread_info {
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_32BIT (1 << TIF_32BIT)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)

2
arch/powerpc/include/asm/thread_info.h
View File

@ -109,7 +109,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_RESTOREALL 11 /* Restore all regs (implies NOERROR) */
#define TIF_NOERROR 12 /* Force successful syscall return */
#define TIF_NOTIFY_RESUME 13 /* callback before returning to user */
#define TIF_FREEZE 14 /* Freezing for suspend */
#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */
#define TIF_RUNLATCH 16 /* Is the runlatch enabled? */
@ -127,7 +126,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_RESTOREALL (1<<TIF_RESTOREALL)
#define _TIF_NOERROR (1<<TIF_NOERROR)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_RUNLATCH (1<<TIF_RUNLATCH)
#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \

2
arch/s390/include/asm/thread_info.h
View File

@ -102,7 +102,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 19 /* restore signal mask in do_signal() */
#define TIF_SINGLE_STEP 20 /* This task is single stepped */
#define TIF_FREEZE 21 /* thread is freezing for suspend */
#define _TIF_SYSCALL (1<<TIF_SYSCALL)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
@ -119,7 +118,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_31BIT (1<<TIF_31BIT)
#define _TIF_SINGLE_STEP (1<<TIF_SINGLE_STEP)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#ifdef CONFIG_64BIT
#define is_32bit_task() (test_thread_flag(TIF_31BIT))

2
arch/sh/include/asm/thread_info.h
View File

@ -122,7 +122,6 @@ extern void init_thread_xstate(void);
#define TIF_SYSCALL_TRACEPOINT 8 /* for ftrace syscall instrumentation */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_FREEZE 19 /* Freezing for suspend */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
@ -133,7 +132,6 @@ extern void init_thread_xstate(void);
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1 << TIF_FREEZE)
/*
* _TIF_ALLWORK_MASK and _TIF_WORK_MASK need to fit within 2 bytes, or we

2
arch/sparc/include/asm/thread_info_32.h
View File

@ -133,7 +133,6 @@ BTFIXUPDEF_CALL(void, free_thread_info, struct thread_info *)
#define TIF_POLLING_NRFLAG 9 /* true if poll_idle() is polling
* TIF_NEED_RESCHED */
#define TIF_MEMDIE 10 /* is terminating due to OOM killer */
#define TIF_FREEZE 11 /* is freezing for suspend */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@ -147,7 +146,6 @@ BTFIXUPDEF_CALL(void, free_thread_info, struct thread_info *)
#define _TIF_DO_NOTIFY_RESUME_MASK (_TIF_NOTIFY_RESUME | \
_TIF_SIGPENDING | \
_TIF_RESTORE_SIGMASK)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#endif /* __KERNEL__ */

2
arch/sparc/include/asm/thread_info_64.h
View File

@ -225,7 +225,6 @@ register struct thread_info *current_thread_info_reg asm("g6");
/* flag bit 12 is available */
#define TIF_MEMDIE 13 /* is terminating due to OOM killer */
#define TIF_POLLING_NRFLAG 14
#define TIF_FREEZE 15 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
@ -237,7 +236,6 @@ register struct thread_info *current_thread_info_reg asm("g6");
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_USER_WORK_MASK ((0xff << TI_FLAG_WSAVED_SHIFT) | \
_TIF_DO_NOTIFY_RESUME_MASK | \

2
arch/um/include/asm/thread_info.h
View File

@ -71,7 +71,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
#define TIF_SYSCALL_AUDIT 6
#define TIF_RESTORE_SIGMASK 7
#define TIF_FREEZE 16 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
@ -80,6 +79,5 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_MEMDIE (1 << TIF_MEMDIE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#endif

2
arch/unicore32/include/asm/thread_info.h
View File

@ -135,14 +135,12 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_SYSCALL_TRACE 8
#define TIF_MEMDIE 18
#define TIF_FREEZE 19
#define TIF_RESTORE_SIGMASK 20
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
/*

2
arch/x86/include/asm/thread_info.h
View File

@ -90,7 +90,6 @@ struct thread_info {
#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
#define TIF_DEBUG 21 /* uses debug registers */
#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
#define TIF_FREEZE 23 /* is freezing for suspend */
#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
#define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
@ -112,7 +111,6 @@ struct thread_info {
#define _TIF_FORK (1 << TIF_FORK)
#define _TIF_DEBUG (1 << TIF_DEBUG)
#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
#define _TIF_FREEZE (1 << TIF_FREEZE)
#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
#define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)

2
arch/xtensa/include/asm/thread_info.h
View File

@ -132,7 +132,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_FREEZE 17 /* is freezing for suspend */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
@ -141,7 +140,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_IRET (1<<TIF_IRET)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_FREEZE (1<<TIF_FREEZE)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */

2
drivers/bluetooth/btmrvl_main.c
View File

@ -475,8 +475,6 @@ static int btmrvl_service_main_thread(void *data)
init_waitqueue_entry(&wait, current);
current->flags |= PF_NOFREEZE;
for (;;) {
add_wait_queue(&thread->wait_q, &wait);

46
drivers/dma/dmatest.c
View File

@ -214,9 +214,18 @@ static unsigned int dmatest_verify(u8 **bufs, unsigned int start,
return error_count;
}
static void dmatest_callback(void *completion)
/* poor man's completion - we want to use wait_event_freezable() on it */
struct dmatest_done {
bool done;
wait_queue_head_t *wait;
};
static void dmatest_callback(void *arg)
{
complete(completion);
struct dmatest_done *done = arg;
done->done = true;
wake_up_all(done->wait);
}
/*
@ -235,7 +244,9 @@ static void dmatest_callback(void *completion)
*/
static int dmatest_func(void *data)
{
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(done_wait);
struct dmatest_thread *thread = data;
struct dmatest_done done = { .wait = &done_wait };
struct dma_chan *chan;
const char *thread_name;
unsigned int src_off, dst_off, len;
@ -252,7 +263,7 @@ static int dmatest_func(void *data)
int i;
thread_name = current->comm;
set_freezable_with_signal();
set_freezable();
ret = -ENOMEM;
@ -306,9 +317,6 @@ static int dmatest_func(void *data)
struct dma_async_tx_descriptor *tx = NULL;
dma_addr_t dma_srcs[src_cnt];
dma_addr_t dma_dsts[dst_cnt];
struct completion cmp;
unsigned long start, tmo, end = 0 /* compiler... */;
bool reload = true;
u8 align = 0;
total_tests++;
@ -391,9 +399,9 @@ static int dmatest_func(void *data)
continue;
}
init_completion(&cmp);
done.done = false;
tx->callback = dmatest_callback;
tx->callback_param = &cmp;
tx->callback_param = &done;
cookie = tx->tx_submit(tx);
if (dma_submit_error(cookie)) {
@ -407,20 +415,20 @@ static int dmatest_func(void *data)
}
dma_async_issue_pending(chan);
do {
start = jiffies;
if (reload)
end = start + msecs_to_jiffies(timeout);
else if (end <= start)
end = start + 1;
tmo = wait_for_completion_interruptible_timeout(&cmp,
end - start);
reload = try_to_freeze();
} while (tmo == -ERESTARTSYS);
wait_event_freezable_timeout(done_wait, done.done,
msecs_to_jiffies(timeout));
status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
if (tmo == 0) {
if (!done.done) {
/*
* We're leaving the timed out dma operation with
* dangling pointer to done_wait. To make this
* correct, we'll need to allocate wait_done for
* each test iteration and perform "who's gonna
* free it this time?" dancing. For now, just
* leave it dangling.
*/
pr_warning("%s: #%u: test timed out\n",
thread_name, total_tests - 1);
failed_tests++;

2
drivers/mfd/twl6030-irq.c
View File

@ -138,8 +138,6 @@ static int twl6030_irq_thread(void *data)
static const unsigned max_i2c_errors = 100;
int ret;
current->flags |= PF_NOFREEZE;
while (!kthread_should_stop()) {
int i;
union {

2
drivers/net/irda/stir4200.c
View File

@ -750,7 +750,7 @@ static int stir_transmit_thread(void *arg)
write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
refrigerator();
try_to_freeze();
if (change_speed(stir, stir->speed))
break;

15
drivers/platform/x86/thinkpad_acpi.c
View File

@ -2456,8 +2456,9 @@ static int hotkey_kthread(void *data)
u32 poll_mask, event_mask;
unsigned int si, so;
unsigned long t;
unsigned int change_detector, must_reset;
unsigned int change_detector;
unsigned int poll_freq;
bool was_frozen;
mutex_lock(&hotkey_thread_mutex);
@ -2488,14 +2489,14 @@ static int hotkey_kthread(void *data)
t = 100; /* should never happen... */
}
t = msleep_interruptible(t);
if (unlikely(kthread_should_stop()))
if (unlikely(kthread_freezable_should_stop(&was_frozen)))
break;
must_reset = try_to_freeze();
if (t > 0 && !must_reset)
if (t > 0 && !was_frozen)
continue;
mutex_lock(&hotkey_thread_data_mutex);
if (must_reset || hotkey_config_change != change_detector) {
if (was_frozen || hotkey_config_change != change_detector) {
/* forget old state on thaw or config change */
si = so;
t = 0;
@ -2528,10 +2529,6 @@ exit:
static void hotkey_poll_stop_sync(void)
{
if (tpacpi_hotkey_task) {
if (frozen(tpacpi_hotkey_task) ||
freezing(tpacpi_hotkey_task))
thaw_process(tpacpi_hotkey_task);
kthread_stop(tpacpi_hotkey_task);
tpacpi_hotkey_task = NULL;
mutex_lock(&hotkey_thread_mutex);

2
drivers/staging/rts_pstor/rtsx.c
View File

@ -466,8 +466,6 @@ static int rtsx_control_thread(void *__dev)
struct rtsx_chip *chip = dev->chip;
struct Scsi_Host *host = rtsx_to_host(dev);
current->flags |= PF_NOFREEZE;
for (;;) {
if (wait_for_completion_interruptible(&dev->cmnd_ready))
break;

13
drivers/usb/storage/usb.c
View File

@ -831,7 +831,8 @@ static int usb_stor_scan_thread(void * __us)
dev_dbg(dev, "device found\n");
set_freezable_with_signal();
set_freezable();
/*
* Wait for the timeout to expire or for a disconnect
*
@ -839,16 +840,16 @@ static int usb_stor_scan_thread(void * __us)
* fail to freeze, but we can't be non-freezable either. Nor can
* khubd freeze while waiting for scanning to complete as it may
* hold the device lock, causing a hang when suspending devices.
* So we request a fake signal when freezing and use
* interruptible sleep to kick us out of our wait early when
* freezing happens.
* So instead of using wait_event_freezable(), explicitly test
* for (DONT_SCAN || freezing) in interruptible wait and proceed
* if any of DONT_SCAN, freezing or timeout has happened.
*/
if (delay_use > 0) {
dev_dbg(dev, "waiting for device to settle "
"before scanning\n");
wait_event_interruptible_timeout(us->delay_wait,
test_bit(US_FLIDX_DONT_SCAN, &us->dflags),
delay_use * HZ);
test_bit(US_FLIDX_DONT_SCAN, &us->dflags) ||
freezing(current), delay_use * HZ);
}
/* If the device is still connected, perform the scanning */

2
fs/btrfs/async-thread.c
View File

@ -340,7 +340,7 @@ again:
if (freezing(current)) {
worker->working = 0;
spin_unlock_irq(&worker->lock);
refrigerator();
try_to_freeze();
} else {
spin_unlock_irq(&worker->lock);
if (!kthread_should_stop()) {

8
fs/btrfs/disk-io.c
View File

@ -1579,9 +1579,7 @@ static int cleaner_kthread(void *arg)
btrfs_run_defrag_inodes(root->fs_info);
}
if (freezing(current)) {
refrigerator();
} else {
if (!try_to_freeze()) {
set_current_state(TASK_INTERRUPTIBLE);
if (!kthread_should_stop())
schedule();
@ -1635,9 +1633,7 @@ sleep:
wake_up_process(root->fs_info->cleaner_kthread);
mutex_unlock(&root->fs_info->transaction_kthread_mutex);
if (freezing(current)) {
refrigerator();
} else {
if (!try_to_freeze()) {
set_current_state(TASK_INTERRUPTIBLE);
if (!kthread_should_stop() &&
!btrfs_transaction_blocked(root->fs_info))

3
fs/ext4/super.c
View File

@ -2884,8 +2884,7 @@ cont_thread:
}
mutex_unlock(&eli->li_list_mtx);
if (freezing(current))
refrigerator();
try_to_freeze();
cur = jiffies;
if ((time_after_eq(cur, next_wakeup)) ||

4
fs/fs-writeback.c
View File

@ -947,7 +947,7 @@ int bdi_writeback_thread(void *data)
trace_writeback_thread_start(bdi);
while (!kthread_should_stop()) {
while (!kthread_freezable_should_stop(NULL)) {
/*
* Remove own delayed wake-up timer, since we are already awake
* and we'll take care of the preriodic write-back.
@ -977,8 +977,6 @@ int bdi_writeback_thread(void *data)
*/
schedule();
}
try_to_freeze();
}
/* Flush any work that raced with us exiting */

4
fs/gfs2/log.c
View File

@ -951,8 +951,8 @@ int gfs2_logd(void *data)
wake_up(&sdp->sd_log_waitq);
t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
if (freezing(current))
refrigerator();
try_to_freeze();
do {
prepare_to_wait(&sdp->sd_logd_waitq, &wait,

4
fs/gfs2/quota.c
View File

@ -1427,8 +1427,8 @@ int gfs2_quotad(void *data)
/* Check for & recover partially truncated inodes */
quotad_check_trunc_list(sdp);
if (freezing(current))
refrigerator();
try_to_freeze();
t = min(quotad_timeo, statfs_timeo);
prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);

2
fs/jbd/journal.c
View File

@ -166,7 +166,7 @@ loop:
*/
jbd_debug(1, "Now suspending kjournald\n");
spin_unlock(&journal->j_state_lock);
refrigerator();
try_to_freeze();
spin_lock(&journal->j_state_lock);
} else {
/*

2
fs/jbd2/journal.c
View File

@ -173,7 +173,7 @@ loop:
*/
jbd_debug(1, "Now suspending kjournald2\n");
write_unlock(&journal->j_state_lock);
refrigerator();
try_to_freeze();
write_lock(&journal->j_state_lock);
} else {
/*

2
fs/jfs/jfs_logmgr.c
View File

@ -2349,7 +2349,7 @@ int jfsIOWait(void *arg)
if (freezing(current)) {
spin_unlock_irq(&log_redrive_lock);
refrigerator();
try_to_freeze();
} else {
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&log_redrive_lock);

4
fs/jfs/jfs_txnmgr.c
View File

@ -2800,7 +2800,7 @@ int jfs_lazycommit(void *arg)
if (freezing(current)) {
LAZY_UNLOCK(flags);
refrigerator();
try_to_freeze();
} else {
DECLARE_WAITQUEUE(wq, current);
@ -2994,7 +2994,7 @@ int jfs_sync(void *arg)
if (freezing(current)) {
TXN_UNLOCK();
refrigerator();
try_to_freeze();
} else {
set_current_state(TASK_INTERRUPTIBLE);
TXN_UNLOCK();

2
fs/nilfs2/segment.c
View File

@ -2470,7 +2470,7 @@ static int nilfs_segctor_thread(void *arg)
if (freezing(current)) {
spin_unlock(&sci->sc_state_lock);
refrigerator();
try_to_freeze();
spin_lock(&sci->sc_state_lock);
} else {
DEFINE_WAIT(wait);

2
fs/xfs/xfs_buf.c
View File

@ -1703,7 +1703,7 @@ xfsbufd(
if (unlikely(freezing(current))) {
set_bit(XBT_FORCE_SLEEP, &target->bt_flags);
refrigerator();
try_to_freeze();
} else {
clear_bit(XBT_FORCE_SLEEP, &target->bt_flags);
}

110
include/linux/freezer.h
View File

@ -5,71 +5,58 @@
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/atomic.h>
#ifdef CONFIG_FREEZER
extern atomic_t system_freezing_cnt; /* nr of freezing conds in effect */
extern bool pm_freezing; /* PM freezing in effect */
extern bool pm_nosig_freezing; /* PM nosig freezing in effect */
/*
* Check if a process has been frozen
*/
static inline int frozen(struct task_struct *p)
static inline bool frozen(struct task_struct *p)
{
return p->flags & PF_FROZEN;
}
extern bool freezing_slow_path(struct task_struct *p);
/*
* Check if there is a request to freeze a process
*/
static inline int freezing(struct task_struct *p)
static inline bool freezing(struct task_struct *p)
{
return test_tsk_thread_flag(p, TIF_FREEZE);
}
/*
* Request that a process be frozen
*/
static inline void set_freeze_flag(struct task_struct *p)
{
set_tsk_thread_flag(p, TIF_FREEZE);
}
/*
* Sometimes we may need to cancel the previous 'freeze' request
*/
static inline void clear_freeze_flag(struct task_struct *p)
{
clear_tsk_thread_flag(p, TIF_FREEZE);
}
static inline bool should_send_signal(struct task_struct *p)
{
return !(p->flags & PF_FREEZER_NOSIG);
if (likely(!atomic_read(&system_freezing_cnt)))
return false;
return freezing_slow_path(p);
}
/* Takes and releases task alloc lock using task_lock() */
extern int thaw_process(struct task_struct *p);
extern void __thaw_task(struct task_struct *t);
extern void refrigerator(void);
extern bool __refrigerator(bool check_kthr_stop);
extern int freeze_processes(void);
extern int freeze_kernel_threads(void);
extern void thaw_processes(void);
static inline int try_to_freeze(void)
static inline bool try_to_freeze(void)
{
if (freezing(current)) {
refrigerator();
return 1;
} else
return 0;
might_sleep();
if (likely(!freezing(current)))
return false;
return __refrigerator(false);
}
extern bool freeze_task(struct task_struct *p, bool sig_only);
extern void cancel_freezing(struct task_struct *p);
extern bool freeze_task(struct task_struct *p);
extern bool set_freezable(void);
#ifdef CONFIG_CGROUP_FREEZER
extern int cgroup_freezing_or_frozen(struct task_struct *task);
extern bool cgroup_freezing(struct task_struct *task);
#else /* !CONFIG_CGROUP_FREEZER */
static inline int cgroup_freezing_or_frozen(struct task_struct *task)
static inline bool cgroup_freezing(struct task_struct *task)
{
return 0;
return false;
}
#endif /* !CONFIG_CGROUP_FREEZER */
@ -117,23 +104,6 @@ static inline int freezer_should_skip(struct task_struct *p)
return !!(p->flags & PF_FREEZER_SKIP);
}
/*
* Tell the freezer that the current task should be frozen by it
*/
static inline void set_freezable(void)
{
current->flags &= ~PF_NOFREEZE;
}
/*
* Tell the freezer that the current task should be frozen by it and that it
* should send a fake signal to the task to freeze it.
*/
static inline void set_freezable_with_signal(void)
{
current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG);
}
/*
* Freezer-friendly wrappers around wait_event_interruptible(),
* wait_event_killable() and wait_event_interruptible_timeout(), originally
@ -152,47 +122,45 @@ static inline void set_freezable_with_signal(void)
#define wait_event_freezable(wq, condition) \
({ \
int __retval; \
do { \
for (;;) { \
__retval = wait_event_interruptible(wq, \
(condition) || freezing(current)); \
if (__retval && !freezing(current)) \
if (__retval || (condition)) \
break; \
else if (!(condition)) \
__retval = -ERESTARTSYS; \
} while (try_to_freeze()); \
try_to_freeze(); \
} \
__retval; \
})
#define wait_event_freezable_timeout(wq, condition, timeout) \
({ \
long __retval = timeout; \
do { \
for (;;) { \
__retval = wait_event_interruptible_timeout(wq, \
(condition) || freezing(current), \
__retval); \
} while (try_to_freeze()); \
if (__retval <= 0 || (condition)) \
break; \
try_to_freeze(); \
} \
__retval; \
})
#else /* !CONFIG_FREEZER */
static inline int frozen(struct task_struct *p) { return 0; }
static inline int freezing(struct task_struct *p) { return 0; }
static inline void set_freeze_flag(struct task_struct *p) {}
static inline void clear_freeze_flag(struct task_struct *p) {}
static inline int thaw_process(struct task_struct *p) { return 1; }
static inline void refrigerator(void) {}
#else /* !CONFIG_FREEZER */
static inline bool frozen(struct task_struct *p) { return false; }
static inline bool freezing(struct task_struct *p) { return false; }
static inline bool __refrigerator(bool check_kthr_stop) { return false; }
static inline int freeze_processes(void) { return -ENOSYS; }
static inline int freeze_kernel_threads(void) { return -ENOSYS; }
static inline void thaw_processes(void) {}
static inline int try_to_freeze(void) { return 0; }
static inline bool try_to_freeze(void) { return false; }
static inline void freezer_do_not_count(void) {}
static inline void freezer_count(void) {}
static inline int freezer_should_skip(struct task_struct *p) { return 0; }
static inline void set_freezable(void) {}
static inline void set_freezable_with_signal(void) {}
#define wait_event_freezable(wq, condition) \
wait_event_interruptible(wq, condition)

1
include/linux/kthread.h
View File

@ -35,6 +35,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
void kthread_bind(struct task_struct *k, unsigned int cpu);
int kthread_stop(struct task_struct *k);
int kthread_should_stop(void);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_data(struct task_struct *k);
int kthreadd(void *unused);

4
include/linux/sched.h
View File

@ -220,7 +220,7 @@ extern char ___assert_task_state[1 - 2*!!(
((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define task_contributes_to_load(task) \
((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
(task->flags & PF_FREEZING) == 0)
(task->flags & PF_FROZEN) == 0)
#define __set_task_state(tsk, state_value) \
do { (tsk)->state = (state_value); } while (0)
@ -1772,7 +1772,6 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
#define PF_MEMALLOC 0x00000800 /* Allocating memory */
#define PF_NPROC_EXCEEDED 0x00001000 /* set_user noticed that RLIMIT_NPROC was exceeded */
#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
#define PF_FREEZING 0x00004000 /* freeze in progress. do not account to load */
#define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
#define PF_FROZEN 0x00010000 /* frozen for system suspend */
#define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
@ -1788,7 +1787,6 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
#define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
#define PF_FREEZER_NOSIG 0x80000000 /* Freezer won't send signals to it */
/*
* Only the _current_ task can read/write to tsk->flags, but other

63
kernel/cgroup_freezer.c
View File

@ -48,19 +48,17 @@ static inline struct freezer *task_freezer(struct task_struct *task)
struct freezer, css);
}
static inline int __cgroup_freezing_or_frozen(struct task_struct *task)
bool cgroup_freezing(struct task_struct *task)
{
enum freezer_state state = task_freezer(task)->state;
return (state == CGROUP_FREEZING) || (state == CGROUP_FROZEN);
}
enum freezer_state state;
bool ret;
int cgroup_freezing_or_frozen(struct task_struct *task)
{
int result;
task_lock(task);
result = __cgroup_freezing_or_frozen(task);
task_unlock(task);
return result;
rcu_read_lock();
state = task_freezer(task)->state;
ret = state == CGROUP_FREEZING || state == CGROUP_FROZEN;
rcu_read_unlock();
return ret;
}
/*
@ -102,9 +100,6 @@ struct cgroup_subsys freezer_subsys;
* freezer_can_attach():
* cgroup_mutex (held by caller of can_attach)
*
* cgroup_freezing_or_frozen():
* task->alloc_lock (to get task's cgroup)
*
* freezer_fork() (preserving fork() performance means can't take cgroup_mutex):
* freezer->lock
* sighand->siglock (if the cgroup is freezing)
@ -130,7 +125,7 @@ struct cgroup_subsys freezer_subsys;
* write_lock css_set_lock (cgroup iterator start)
* task->alloc_lock
* read_lock css_set_lock (cgroup iterator start)
* task->alloc_lock (inside thaw_process(), prevents race with refrigerator())
* task->alloc_lock (inside __thaw_task(), prevents race with refrigerator())
* sighand->siglock
*/
static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
@ -150,7 +145,11 @@ static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
static void freezer_destroy(struct cgroup_subsys *ss,
struct cgroup *cgroup)
{
kfree(cgroup_freezer(cgroup));
struct freezer *freezer = cgroup_freezer(cgroup);
if (freezer->state != CGROUP_THAWED)
atomic_dec(&system_freezing_cnt);
kfree(freezer);
}
/*
@ -177,13 +176,7 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
static int freezer_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
rcu_read_lock();
if (__cgroup_freezing_or_frozen(tsk)) {
rcu_read_unlock();
return -EBUSY;
}
rcu_read_unlock();
return 0;
return cgroup_freezing(tsk) ? -EBUSY : 0;
}
static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
@ -213,7 +206,7 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
/* Locking avoids race with FREEZING -> THAWED transitions. */
if (freezer->state == CGROUP_FREEZING)
freeze_task(task, true);
freeze_task(task);
spin_unlock_irq(&freezer->lock);
}
@ -231,7 +224,7 @@ static void update_if_frozen(struct cgroup *cgroup,
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
ntotal++;
if (frozen(task))
if (freezing(task) && frozen(task))
nfrozen++;
}
@ -279,10 +272,9 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
struct task_struct *task;
unsigned int num_cant_freeze_now = 0;
freezer->state = CGROUP_FREEZING;
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
if (!freeze_task(task, true))
if (!freeze_task(task))
continue;
if (frozen(task))
continue;
@ -300,12 +292,9 @@ static void unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
struct task_struct *task;
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
thaw_process(task);
}
while ((task = cgroup_iter_next(cgroup, &it)))
__thaw_task(task);
cgroup_iter_end(cgroup, &it);
freezer->state = CGROUP_THAWED;
}
static int freezer_change_state(struct cgroup *cgroup,
@ -319,20 +308,24 @@ static int freezer_change_state(struct cgroup *cgroup,
spin_lock_irq(&freezer->lock);
update_if_frozen(cgroup, freezer);
if (goal_state == freezer->state)
goto out;
switch (goal_state) {
case CGROUP_THAWED:
if (freezer->state != CGROUP_THAWED)
atomic_dec(&system_freezing_cnt);
freezer->state = CGROUP_THAWED;
unfreeze_cgroup(cgroup, freezer);
break;
case CGROUP_FROZEN:
if (freezer->state == CGROUP_THAWED)
atomic_inc(&system_freezing_cnt);
freezer->state = CGROUP_FREEZING;
retval = try_to_freeze_cgroup(cgroup, freezer);
break;
default:
BUG();
}
out:
spin_unlock_irq(&freezer->lock);
return retval;

3
kernel/exit.c
View File

@ -679,8 +679,6 @@ static void exit_mm(struct task_struct * tsk)
tsk->mm = NULL;
up_read(&mm->mmap_sem);
enter_lazy_tlb(mm, current);
/* We don't want this task to be frozen prematurely */
clear_freeze_flag(tsk);
task_unlock(tsk);
mm_update_next_owner(mm);
mmput(mm);
@ -1040,6 +1038,7 @@ NORET_TYPE void do_exit(long code)
exit_rcu();
/* causes final put_task_struct in finish_task_switch(). */
tsk->state = TASK_DEAD;
tsk->flags |= PF_NOFREEZE; /* tell freezer to ignore us */
schedule();
BUG();
/* Avoid "noreturn function does return". */

1
kernel/fork.c
View File

@ -992,7 +992,6 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
new_flags |= PF_FORKNOEXEC;
new_flags |= PF_STARTING;
p->flags = new_flags;
clear_freeze_flag(p);
}
SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)

199
kernel/freezer.c
View File

@ -9,101 +9,114 @@
#include <linux/export.h>
#include <linux/syscalls.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
/*
* freezing is complete, mark current process as frozen
/* total number of freezing conditions in effect */
atomic_t system_freezing_cnt = ATOMIC_INIT(0);
EXPORT_SYMBOL(system_freezing_cnt);
/* indicate whether PM freezing is in effect, protected by pm_mutex */
bool pm_freezing;
bool pm_nosig_freezing;
/* protects freezing and frozen transitions */
static DEFINE_SPINLOCK(freezer_lock);
/**
* freezing_slow_path - slow path for testing whether a task needs to be frozen
* @p: task to be tested
*
* This function is called by freezing() if system_freezing_cnt isn't zero
* and tests whether @p needs to enter and stay in frozen state. Can be
* called under any context. The freezers are responsible for ensuring the
* target tasks see the updated state.
*/
static inline void frozen_process(void)
bool freezing_slow_path(struct task_struct *p)
{
if (!unlikely(current->flags & PF_NOFREEZE)) {
current->flags |= PF_FROZEN;
smp_wmb();
}
clear_freeze_flag(current);
if (p->flags & PF_NOFREEZE)
return false;
if (pm_nosig_freezing || cgroup_freezing(p))
return true;
if (pm_freezing && !(p->flags & PF_KTHREAD))
return true;
return false;
}
EXPORT_SYMBOL(freezing_slow_path);
/* Refrigerator is place where frozen processes are stored :-). */
void refrigerator(void)
bool __refrigerator(bool check_kthr_stop)
{
/* Hmm, should we be allowed to suspend when there are realtime
processes around? */
long save;
bool was_frozen = false;
long save = current->state;
task_lock(current);
if (freezing(current)) {
frozen_process();
task_unlock(current);
} else {
task_unlock(current);
return;
}
save = current->state;
pr_debug("%s entered refrigerator\n", current->comm);
spin_lock_irq(&current->sighand->siglock);
recalc_sigpending(); /* We sent fake signal, clean it up */
spin_unlock_irq(&current->sighand->siglock);
/* prevent accounting of that task to load */
current->flags |= PF_FREEZING;
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (!frozen(current))
spin_lock_irq(&freezer_lock);
current->flags |= PF_FROZEN;
if (!freezing(current) ||
(check_kthr_stop && kthread_should_stop()))
current->flags &= ~PF_FROZEN;
spin_unlock_irq(&freezer_lock);
if (!(current->flags & PF_FROZEN))
break;
was_frozen = true;
schedule();
}
/* Remove the accounting blocker */
current->flags &= ~PF_FREEZING;
pr_debug("%s left refrigerator\n", current->comm);
__set_current_state(save);
/*
* Restore saved task state before returning. The mb'd version
* needs to be used; otherwise, it might silently break
* synchronization which depends on ordered task state change.
*/
set_current_state(save);
return was_frozen;
}
EXPORT_SYMBOL(refrigerator);
EXPORT_SYMBOL(__refrigerator);
static void fake_signal_wake_up(struct task_struct *p)
{
unsigned long flags;
spin_lock_irqsave(&p->sighand->siglock, flags);
if (lock_task_sighand(p, &flags)) {
signal_wake_up(p, 0);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
unlock_task_sighand(p, &flags);
}
}
/**
* freeze_task - send a freeze request to given task
* @p: task to send the request to
* @sig_only: if set, the request will only be sent if the task has the
* PF_FREEZER_NOSIG flag unset
* Return value: 'false', if @sig_only is set and the task has
* PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise
*
* The freeze request is sent by setting the tasks's TIF_FREEZE flag and
* either sending a fake signal to it or waking it up, depending on whether
* or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task
* has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its
* TIF_FREEZE flag will not be set.
* If @p is freezing, the freeze request is sent by setting %TIF_FREEZE
* flag and either sending a fake signal to it or waking it up, depending
* on whether it has %PF_FREEZER_NOSIG set.
*
* RETURNS:
* %false, if @p is not freezing or already frozen; %true, otherwise
*/
bool freeze_task(struct task_struct *p, bool sig_only)
bool freeze_task(struct task_struct *p)
{
/*
* We first check if the task is freezing and next if it has already
* been frozen to avoid the race with frozen_process() which first marks
* the task as frozen and next clears its TIF_FREEZE.
*/
if (!freezing(p)) {
smp_rmb();
if (frozen(p))
return false;
unsigned long flags;
if (!sig_only || should_send_signal(p))
set_freeze_flag(p);
else
spin_lock_irqsave(&freezer_lock, flags);
if (!freezing(p) || frozen(p)) {
spin_unlock_irqrestore(&freezer_lock, flags);
return false;
}
if (should_send_signal(p)) {
if (!(p->flags & PF_KTHREAD)) {
fake_signal_wake_up(p);
/*
* fake_signal_wake_up() goes through p's scheduler
@ -111,56 +124,48 @@ bool freeze_task(struct task_struct *p, bool sig_only)
* TASK_RUNNING transition can't race with task state
* testing in try_to_freeze_tasks().
*/
} else if (sig_only) {
return false;
} else {
wake_up_state(p, TASK_INTERRUPTIBLE);
}
spin_unlock_irqrestore(&freezer_lock, flags);
return true;
}
void cancel_freezing(struct task_struct *p)
void __thaw_task(struct task_struct *p)
{
unsigned long flags;
if (freezing(p)) {
pr_debug(" clean up: %s\n", p->comm);
clear_freeze_flag(p);
spin_lock_irqsave(&p->sighand->siglock, flags);
recalc_sigpending_and_wake(p);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
}
static int __thaw_process(struct task_struct *p)
{
if (frozen(p)) {
p->flags &= ~PF_FROZEN;
return 1;
}
clear_freeze_flag(p);
return 0;
}
/*
* Wake up a frozen process
*
* task_lock() is needed to prevent the race with refrigerator() which may
* occur if the freezing of tasks fails. Namely, without the lock, if the
* freezing of tasks failed, thaw_tasks() might have run before a task in
* refrigerator() could call frozen_process(), in which case the task would be
* frozen and no one would thaw it.
/*
* Clear freezing and kick @p if FROZEN. Clearing is guaranteed to
* be visible to @p as waking up implies wmb. Waking up inside
* freezer_lock also prevents wakeups from leaking outside
* refrigerator.
*/
int thaw_process(struct task_struct *p)
{
task_lock(p);
if (__thaw_process(p) == 1) {
task_unlock(p);
spin_lock_irqsave(&freezer_lock, flags);
if (frozen(p))
wake_up_process(p);
return 1;
}
task_unlock(p);
return 0;
spin_unlock_irqrestore(&freezer_lock, flags);
}
EXPORT_SYMBOL(thaw_process);
/**
* set_freezable - make %current freezable
*
* Mark %current freezable and enter refrigerator if necessary.
*/
bool set_freezable(void)
{
might_sleep();
/*
* Modify flags while holding freezer_lock. This ensures the
* freezer notices that we aren't frozen yet or the freezing
* condition is visible to try_to_freeze() below.
*/
spin_lock_irq(&freezer_lock);
current->flags &= ~PF_NOFREEZE;
spin_unlock_irq(&freezer_lock);
return try_to_freeze();
}
EXPORT_SYMBOL(set_freezable);

27
kernel/kthread.c
View File

@ -58,6 +58,31 @@ int kthread_should_stop(void)
}
EXPORT_SYMBOL(kthread_should_stop);
/**
* kthread_freezable_should_stop - should this freezable kthread return now?
* @was_frozen: optional out parameter, indicates whether %current was frozen
*
* kthread_should_stop() for freezable kthreads, which will enter
* refrigerator if necessary. This function is safe from kthread_stop() /
* freezer deadlock and freezable kthreads should use this function instead
* of calling try_to_freeze() directly.
*/
bool kthread_freezable_should_stop(bool *was_frozen)
{
bool frozen = false;
might_sleep();
if (unlikely(freezing(current)))
frozen = __refrigerator(true);
if (was_frozen)
*was_frozen = frozen;
return kthread_should_stop();
}
EXPORT_SYMBOL_GPL(kthread_freezable_should_stop);
/**
* kthread_data - return data value specified on kthread creation
* @task: kthread task in question
@ -257,7 +282,7 @@ int kthreadd(void *unused)
set_cpus_allowed_ptr(tsk, cpu_all_mask);
set_mems_allowed(node_states[N_HIGH_MEMORY]);
current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG;
current->flags |= PF_NOFREEZE;
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);

15
kernel/power/hibernate.c
View File

@ -611,17 +611,6 @@ static void power_down(void)
while(1);
}
static int prepare_processes(void)
{
int error = 0;
if (freeze_processes()) {
error = -EBUSY;
thaw_processes();
}
return error;
}
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
@ -654,7 +643,7 @@ int hibernate(void)
sys_sync();
printk("done.\n");
error = prepare_processes();
error = freeze_processes();
if (error)
goto Finish;
@ -815,7 +804,7 @@ static int software_resume(void)
goto close_finish;
pr_debug("PM: Preparing processes for restore.\n");
error = prepare_processes();
error = freeze_processes();
if (error) {
swsusp_close(FMODE_READ);
goto Done;

83
kernel/power/process.c
View File

@ -22,16 +22,7 @@
*/
#define TIMEOUT (20 * HZ)
static inline int freezable(struct task_struct * p)
{
if ((p == current) ||
(p->flags & PF_NOFREEZE) ||
(p->exit_state != 0))
return 0;
return 1;
}
static int try_to_freeze_tasks(bool sig_only)
static int try_to_freeze_tasks(bool user_only)
{
struct task_struct *g, *p;
unsigned long end_time;
@ -46,17 +37,14 @@ static int try_to_freeze_tasks(bool sig_only)
end_time = jiffies + TIMEOUT;
if (!sig_only)
if (!user_only)
freeze_workqueues_begin();
while (true) {
todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
if (frozen(p) || !freezable(p))
continue;
if (!freeze_task(p, sig_only))
if (p == current || !freeze_task(p))
continue;
/*
@ -77,7 +65,7 @@ static int try_to_freeze_tasks(bool sig_only)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
if (!sig_only) {
if (!user_only) {
wq_busy = freeze_workqueues_busy();
todo += wq_busy;
}
@ -103,11 +91,6 @@ static int try_to_freeze_tasks(bool sig_only)
elapsed_csecs = elapsed_csecs64;
if (todo) {
/* This does not unfreeze processes that are already frozen
* (we have slightly ugly calling convention in that respect,
* and caller must call thaw_processes() if something fails),
* but it cleans up leftover PF_FREEZE requests.
*/
printk("\n");
printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds "
"(%d tasks refusing to freeze, wq_busy=%d):\n",
@ -115,15 +98,11 @@ static int try_to_freeze_tasks(bool sig_only)
elapsed_csecs / 100, elapsed_csecs % 100,
todo - wq_busy, wq_busy);
thaw_workqueues();
read_lock(&tasklist_lock);
do_each_thread(g, p) {
task_lock(p);
if (!wakeup && freezing(p) && !freezer_should_skip(p))
if (!wakeup && !freezer_should_skip(p) &&
p != current && freezing(p) && !frozen(p))
sched_show_task(p);
cancel_freezing(p);
task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
} else {
@ -136,12 +115,18 @@ static int try_to_freeze_tasks(bool sig_only)
/**
* freeze_processes - Signal user space processes to enter the refrigerator.
*
* On success, returns 0. On failure, -errno and system is fully thawed.
*/
int freeze_processes(void)
{
int error;
if (!pm_freezing)
atomic_inc(&system_freezing_cnt);
printk("Freezing user space processes ... ");
pm_freezing = true;
error = try_to_freeze_tasks(true);
if (!error) {
printk("done.");
@ -150,17 +135,22 @@ int freeze_processes(void)
printk("\n");
BUG_ON(in_atomic());
if (error)
thaw_processes();
return error;
}
/**
* freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
*
* On success, returns 0. On failure, -errno and system is fully thawed.
*/
int freeze_kernel_threads(void)
{
int error;
printk("Freezing remaining freezable tasks ... ");
pm_nosig_freezing = true;
error = try_to_freeze_tasks(false);
if (!error)
printk("done.");
@ -168,37 +158,32 @@ int freeze_kernel_threads(void)
printk("\n");
BUG_ON(in_atomic());
if (error)
thaw_processes();
return error;
}
static void thaw_tasks(bool nosig_only)
{
struct task_struct *g, *p;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
if (!freezable(p))
continue;
if (nosig_only && should_send_signal(p))
continue;
if (cgroup_freezing_or_frozen(p))
continue;
thaw_process(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
}
void thaw_processes(void)
{
struct task_struct *g, *p;
if (pm_freezing)
atomic_dec(&system_freezing_cnt);
pm_freezing = false;
pm_nosig_freezing = false;
oom_killer_enable();
printk("Restarting tasks ... ");
thaw_workqueues();
thaw_tasks(true);
thaw_tasks(false);
read_lock(&tasklist_lock);
do_each_thread(g, p) {
__thaw_task(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
schedule();
printk("done.\n");
}

8
kernel/power/suspend.c
View File

@ -106,13 +106,11 @@ static int suspend_prepare(void)
goto Finish;
error = suspend_freeze_processes();
if (error) {
suspend_stats.failed_freeze++;
dpm_save_failed_step(SUSPEND_FREEZE);
} else
if (!error)
return 0;
suspend_thaw_processes();
suspend_stats.failed_freeze++;
dpm_save_failed_step(SUSPEND_FREEZE);
usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);

4
kernel/power/user.c
View File

@ -257,10 +257,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;
error = freeze_processes();
if (error) {
thaw_processes();
if (error)
usermodehelper_enable();
}
if (!error)
data->frozen = 1;
break;

8
mm/backing-dev.c
View File

@ -600,14 +600,10 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi)
/*
* Finally, kill the kernel thread. We don't need to be RCU
* safe anymore, since the bdi is gone from visibility. Force
* unfreeze of the thread before calling kthread_stop(), otherwise
* it would never exet if it is currently stuck in the refrigerator.
* safe anymore, since the bdi is gone from visibility.
*/
if (bdi->wb.task) {
thaw_process(bdi->wb.task);
if (bdi->wb.task)
kthread_stop(bdi->wb.task);
}
}
/*

2
mm/oom_kill.c
View File

@ -328,7 +328,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
*/
if (test_tsk_thread_flag(p, TIF_MEMDIE)) {
if (unlikely(frozen(p)))
thaw_process(p);
__thaw_task(p);
return ERR_PTR(-1UL);
}
if (!p->mm)