Messages in this thread Patch in this message | | | Date | Mon, 27 Jun 2005 08:13:27 -0700 (PDT) | From | Christoph Lameter <> | Subject | Re: [RFC] Fix SMP brokenness for PF_FREEZE and make freezing usable for other purposes |
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On Mon, 27 Jun 2005, Pavel Machek wrote:
> Approach seems okay... Perhaps better place is something like > kernel/freezer.c so it stays separate file? It is not really scheduler > core, and it is only conditionally compiled...
There is already lots of other conditional code in kernel/sched.c and this is just one function. It is scheduler like and uses scheduler variables since it suspends a process. So lets move it there.
I think this is as far as I can take it. Could you test this and see if it works okay?
For suspension for migration do:
1. down(&freezer_sem)
2. Signal processes to sleep (see kernel/power/process.c). Basically set the TIF_FREEZE and may be do the fake signal thing.
3. If all processes have PF_FROZEN set then they are asleep.
4. Do migration things
5. complete_all(&thaw)
6. up(&freezer_sem)
---- Revise handling of freezing in the suspend code
The current suspend code modifies thread flags from outside the context of process. This creates a SMP race.
The patch fixes that by introducing a TIF_FREEZE flag (for all arches). Also
- Uses a completion handler instead of waiting in a schedule loop in the refrigerator.
- Introduces a semaphore freezer_sem to provide a way that multiple kernel subsystems can use the freezing ability without interfering with one another.
- Include necessary definitions for the migration code if CONFIG_MIGRATE is set.
- Removes PF_FREEZE
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Index: linux-2.6.12/include/linux/sched.h =================================================================== --- linux-2.6.12.orig/include/linux/sched.h 2005-06-27 05:20:15.000000000 +0000 +++ linux-2.6.12/include/linux/sched.h 2005-06-27 05:33:46.000000000 +0000 @@ -804,7 +804,6 @@ do { if (atomic_dec_and_test(&(tsk)->usa #define PF_MEMALLOC 0x00000800 /* Allocating memory */ #define PF_FLUSHER 0x00001000 /* responsible for disk writeback */ #define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */ -#define PF_FREEZE 0x00004000 /* this task is being frozen for suspend now */ #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 */ @@ -1265,78 +1264,37 @@ extern void normalize_rt_tasks(void); #endif -#ifdef CONFIG_PM -/* - * Check if a process has been frozen - */ -static inline int frozen(struct task_struct *p) -{ - return p->flags & PF_FROZEN; -} - -/* - * Check if there is a request to freeze a process - */ -static inline int freezing(struct task_struct *p) -{ - return p->flags & PF_FREEZE; -} +#if defined(CONFIG_PM) || defined(CONFIG_MIGRATE) +extern struct semaphore freezer_sem; +extern struct completion thaw; -/* - * Request that a process be frozen - * FIXME: SMP problem. We may not modify other process' flags! - */ -static inline void freeze(struct task_struct *p) -{ - p->flags |= PF_FREEZE; -} - -/* - * Wake up a frozen process - */ -static inline int thaw_process(struct task_struct *p) -{ - if (frozen(p)) { - p->flags &= ~PF_FROZEN; - wake_up_process(p); - return 1; - } - return 0; -} +extern void refrigerator(void); -/* - * freezing is complete, mark process as frozen - */ -static inline void frozen_process(struct task_struct *p) +static inline int freezing(struct task_struct *p) { - p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN; + return test_ti_thread_flag(p->thread_info, TIF_FREEZE); } -extern void refrigerator(void); -extern int freeze_processes(void); -extern void thaw_processes(void); - static inline int try_to_freeze(void) { - if (freezing(current)) { + if (test_thread_flag(TIF_FREEZE)) { refrigerator(); return 1; } else return 0; } #else -static inline int frozen(struct task_struct *p) { return 0; } +static inline void refrigerator(void) {} static inline int freezing(struct task_struct *p) { return 0; } -static inline void freeze(struct task_struct *p) { BUG(); } -static inline int thaw_process(struct task_struct *p) { return 1; } -static inline void frozen_process(struct task_struct *p) { BUG(); } +static inline int try_to_freeze(void) { return 0; } +#endif -static inline void refrigerator(void) {} +#ifdef CONFIG_PM +extern int freeze_processes(void); +extern void thaw_processes(void); +#else static inline int freeze_processes(void) { BUG(); return 0; } static inline void thaw_processes(void) {} - -static inline int try_to_freeze(void) { return 0; } - #endif /* CONFIG_PM */ #endif /* __KERNEL__ */ Index: linux-2.6.12/kernel/power/process.c =================================================================== --- linux-2.6.12.orig/kernel/power/process.c 2005-06-27 05:20:15.000000000 +0000 +++ linux-2.6.12/kernel/power/process.c 2005-06-27 15:07:46.000000000 +0000 @@ -18,7 +18,6 @@ */ #define TIMEOUT (6 * HZ) - static inline int freezeable(struct task_struct * p) { if ((p == current) || @@ -31,28 +30,6 @@ static inline int freezeable(struct task return 1; } -/* Refrigerator is place where frozen processes are stored :-). */ -void refrigerator(void) -{ - /* Hmm, should we be allowed to suspend when there are realtime - processes around? */ - long save; - save = current->state; - current->state = TASK_UNINTERRUPTIBLE; - pr_debug("%s entered refrigerator\n", current->comm); - printk("="); - - frozen_process(current); - spin_lock_irq(¤t->sighand->siglock); - recalc_sigpending(); /* We sent fake signal, clean it up */ - spin_unlock_irq(¤t->sighand->siglock); - - while (frozen(current)) - schedule(); - pr_debug("%s left refrigerator\n", current->comm); - current->state = save; -} - /* 0 = success, else # of processes that we failed to stop */ int freeze_processes(void) { @@ -60,6 +37,7 @@ int freeze_processes(void) unsigned long start_time; struct task_struct *g, *p; + down(&freezer_sem); printk( "Stopping tasks: " ); start_time = jiffies; do { @@ -69,12 +47,12 @@ int freeze_processes(void) unsigned long flags; if (!freezeable(p)) continue; - if ((frozen(p)) || + if ((p->flags & PF_FROZEN) || (p->state == TASK_TRACED) || (p->state == TASK_STOPPED)) continue; - freeze(p); + set_thread_flag(TIF_FREEZE); spin_lock_irqsave(&p->sighand->siglock, flags); signal_wake_up(p, 0); spin_unlock_irqrestore(&p->sighand->siglock, flags); @@ -96,20 +74,6 @@ int freeze_processes(void) void thaw_processes(void) { - struct task_struct *g, *p; - - printk( "Restarting tasks..." ); - read_lock(&tasklist_lock); - do_each_thread(g, p) { - if (!freezeable(p)) - continue; - if (!thaw_process(p)) - printk(KERN_INFO " Strange, %s not stopped\n", p->comm ); - } while_each_thread(g, p); - - read_unlock(&tasklist_lock); - schedule(); - printk( " done\n" ); + complete_all(&thaw); + up(&freezer_sem); } - -EXPORT_SYMBOL(refrigerator); Index: linux-2.6.12/include/asm-x86_64/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-x86_64/thread_info.h 2005-06-27 05:20:15.000000000 +0000 +++ linux-2.6.12/include/asm-x86_64/thread_info.h 2005-06-27 05:37:24.000000000 +0000 @@ -108,6 +108,7 @@ static inline struct thread_info *stack_ #define TIF_FORK 18 /* ret_from_fork */ #define TIF_ABI_PENDING 19 #define TIF_MEMDIE 20 +#define TIF_FREEZE 21 /* Freeze process */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-ia64/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-ia64/thread_info.h 2005-06-27 05:20:15.000000000 +0000 +++ linux-2.6.12/include/asm-ia64/thread_info.h 2005-06-27 05:26:12.000000000 +0000 @@ -76,6 +76,7 @@ struct thread_info { #define TIF_SIGDELAYED 5 /* signal delayed from MCA/INIT/NMI/PMI context */ #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 17 +#define TIF_FREEZE 18 /* Freeze process */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) Index: linux-2.6.12/include/asm-i386/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-i386/thread_info.h 2005-06-27 05:20:15.000000000 +0000 +++ linux-2.6.12/include/asm-i386/thread_info.h 2005-06-27 05:25:49.000000000 +0000 @@ -143,6 +143,7 @@ register unsigned long current_stack_poi #define TIF_SECCOMP 8 /* secure computing */ #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 17 +#define TIF_FREEZE 18 /* Freeze thread */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-xtensa/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-xtensa/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-xtensa/thread_info.h 2005-06-27 05:36:54.000000000 +0000 @@ -118,6 +118,7 @@ static inline struct thread_info *curren #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ #define TIF_IRET 5 /* return with iret */ #define TIF_MEMDIE 6 +#define TIF_FREEZE 7 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-h8300/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-h8300/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-h8300/thread_info.h 2005-06-27 05:25:25.000000000 +0000 @@ -94,6 +94,7 @@ static inline struct thread_info *curren #define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 5 +#define TIF_FREEZE 6 /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-ppc/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-ppc/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-ppc/thread_info.h 2005-06-27 05:28:53.000000000 +0000 @@ -80,6 +80,7 @@ static inline struct thread_info *curren #define TIF_MEMDIE 5 #define TIF_SYSCALL_AUDIT 6 /* syscall auditing active */ #define TIF_SECCOMP 7 /* secure computing */ +#define TIF_FREEZE 8 /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-sh64/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-sh64/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-sh64/thread_info.h 2005-06-27 05:35:02.000000000 +0000 @@ -80,6 +80,7 @@ static inline struct thread_info *curren #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_MEMDIE 4 +#define TIF_FREEZE 5 #endif /* __KERNEL__ */ Index: linux-2.6.12/include/asm-alpha/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-alpha/thread_info.h 2005-06-17 19:48:29.000000000 +0000 +++ linux-2.6.12/include/asm-alpha/thread_info.h 2005-06-27 05:23:06.000000000 +0000 @@ -78,6 +78,7 @@ register struct thread_info *__current_t #define TIF_UAC_NOFIX 7 #define TIF_UAC_SIGBUS 8 #define TIF_MEMDIE 9 +#define TIF_FREEZE 10 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-sparc/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-sparc/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-sparc/thread_info.h 2005-06-27 05:35:23.000000000 +0000 @@ -139,6 +139,7 @@ BTFIXUPDEF_CALL(void, free_thread_info, #define TIF_POLLING_NRFLAG 9 /* true if poll_idle() is polling * TIF_NEED_RESCHED */ #define TIF_MEMDIE 10 +#define TIF_FREEZE 11 /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-frv/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-frv/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-frv/thread_info.h 2005-06-27 05:25:02.000000000 +0000 @@ -133,6 +133,7 @@ register struct thread_info *__current_t #define TIF_IRET 5 /* return with iret */ #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 17 /* OOM killer killed process */ +#define TIF_FREEZE 18 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-parisc/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-parisc/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-parisc/thread_info.h 2005-06-27 05:28:34.000000000 +0000 @@ -64,6 +64,7 @@ struct thread_info { #define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_32BIT 5 /* 32 bit binary */ #define TIF_MEMDIE 6 +#define TIF_FREEZE 7 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-m68knommu/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-m68knommu/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-m68knommu/thread_info.h 2005-06-27 05:27:13.000000000 +0000 @@ -91,6 +91,7 @@ static inline struct thread_info *curren #define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 5 +#define TIF_FREEZE 6 /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-m68k/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-m68k/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-m68k/thread_info.h 2005-06-27 05:26:49.000000000 +0000 @@ -49,6 +49,7 @@ struct thread_info { #define TIF_SIGPENDING 3 /* signal pending */ #define TIF_NEED_RESCHED 4 /* rescheduling necessary */ #define TIF_MEMDIE 5 +#define TIF_FREEZE 6 extern int thread_flag_fixme(void); Index: linux-2.6.12/include/asm-sh/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-sh/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-sh/thread_info.h 2005-06-27 05:34:43.000000000 +0000 @@ -84,6 +84,7 @@ static inline struct thread_info *curren #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 +#define TIF_FREEZE 19 #define TIF_USERSPACE 31 /* true if FS sets userspace */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-s390/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-s390/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-s390/thread_info.h 2005-06-27 05:34:19.000000000 +0000 @@ -102,6 +102,7 @@ static inline struct thread_info *curren TIF_NEED_RESCHED */ #define TIF_31BIT 18 /* 32bit process */ #define TIF_MEMDIE 19 +#define TIF_FREEZE 20 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-arm/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-arm/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-arm/thread_info.h 2005-06-27 05:23:34.000000000 +0000 @@ -132,6 +132,7 @@ extern void iwmmxt_task_release(struct t #define TIF_POLLING_NRFLAG 16 #define TIF_USING_IWMMXT 17 #define TIF_MEMDIE 18 +#define TIF_FREEZE 19 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) Index: linux-2.6.12/include/asm-v850/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-v850/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-v850/thread_info.h 2005-06-27 05:36:25.000000000 +0000 @@ -85,6 +85,7 @@ struct thread_info { #define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 5 +#define TIF_FREEZE 6 /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-mips/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-mips/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-mips/thread_info.h 2005-06-27 05:27:41.000000000 +0000 @@ -117,6 +117,7 @@ register struct thread_info *__current_t #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 +#define TIF_FREEZE 19 #define TIF_SYSCALL_TRACE 31 /* syscall trace active */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-cris/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-cris/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-cris/thread_info.h 2005-06-27 05:24:28.000000000 +0000 @@ -86,6 +86,7 @@ struct thread_info { #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_MEMDIE 17 +#define TIF_FREEZE 18 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-arm26/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-arm26/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-arm26/thread_info.h 2005-06-27 05:24:02.000000000 +0000 @@ -127,6 +127,7 @@ extern void free_thread_info(struct thre #define TIF_USED_FPU 16 #define TIF_POLLING_NRFLAG 17 #define TIF_MEMDIE 18 +#define TIF_FREEZE 19 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) Index: linux-2.6.12/include/asm-sparc64/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-sparc64/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-sparc64/thread_info.h 2005-06-27 05:35:45.000000000 +0000 @@ -229,6 +229,7 @@ register struct thread_info *current_thr */ #define TIF_ABI_PENDING 12 #define TIF_MEMDIE 13 +#define TIF_FREEZE 14 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-m32r/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-m32r/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-m32r/thread_info.h 2005-06-27 05:26:33.000000000 +0000 @@ -156,6 +156,7 @@ static inline unsigned int get_thread_fa #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ /* 31..28 fault code */ #define TIF_MEMDIE 17 +#define TIF_FREEZE 18 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) Index: linux-2.6.12/include/asm-ppc64/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-ppc64/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-ppc64/thread_info.h 2005-06-27 05:29:13.000000000 +0000 @@ -102,6 +102,7 @@ static inline struct thread_info *curren #define TIF_SINGLESTEP 9 /* singlestepping active */ #define TIF_MEMDIE 10 #define TIF_SECCOMP 11 /* secure computing */ +#define TIF_FREEZE 12 /* as above, but as bit values */ #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) Index: linux-2.6.12/include/asm-um/thread_info.h =================================================================== --- linux-2.6.12.orig/include/asm-um/thread_info.h 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/include/asm-um/thread_info.h 2005-06-27 05:36:07.000000000 +0000 @@ -72,6 +72,7 @@ static inline struct thread_info *curren #define TIF_RESTART_BLOCK 4 #define TIF_MEMDIE 5 #define TIF_SYSCALL_AUDIT 6 +#define TIF_FREEZE 7 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) Index: linux-2.6.12/kernel/sched.c =================================================================== --- linux-2.6.12.orig/kernel/sched.c 2005-06-27 02:23:01.000000000 +0000 +++ linux-2.6.12/kernel/sched.c 2005-06-27 15:08:19.000000000 +0000 @@ -5203,6 +5203,25 @@ void __init sched_init(void) init_idle(current, smp_processor_id()); } +#if defined(CONFIG_PM) || defined(CONFIG_MIGRATE) +DECLARE_MUTEX(freezer_sem); +DECLARE_COMPLETION(thaw); + +void refrigerator(void) +{ + current->flags |= PF_FROZEN; + clear_thread_flag(TIF_FREEZE); + /* A fake signal 0 may have been sent. Recalculate sigpending */ + spin_lock_irq(¤t->sighand->siglock); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + wait_for_completion(&thaw); + current->flags &= ~PF_FROZEN; +} +EXPORT_SYMBOL(refrigerator); +#endif + + #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP void __might_sleep(char *file, int line) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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