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authorRafael J. Wysocki <rjw@sisk.pl>2011-12-07 01:12:50 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2011-12-07 01:12:50 +0400
commit2e8e89e392c62636ee33532358607baef2863173 (patch)
treed995a25c68eef57dea580b0f06ba8af76758775a /include/linux
parent0c6aebe31861c470c8cfbfdfdfd72d1369a6440b (diff)
parentd310310cbff18ec385c6ab4d58f33b100192a96a (diff)
downloadlinux-2e8e89e392c62636ee33532358607baef2863173.tar.xz
Merge branch 'pm-freezer' into pm-sleep
* pm-freezer: (26 commits) Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer Freezer: fix more fallout from the thaw_process rename 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 ...
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/freezer.h129
-rw-r--r--include/linux/kthread.h1
-rw-r--r--include/linux/sched.h4
3 files changed, 65 insertions, 69 deletions
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index a5386e3ee756..30f06c220467 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -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;
}
-/*
- * Check if there is a request to freeze a process
- */
-static inline int 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);
-}
+extern bool freezing_slow_path(struct task_struct *p);
/*
- * Sometimes we may need to cancel the previous 'freeze' request
+ * Check if there is a request to freeze a process
*/
-static inline void clear_freeze_flag(struct task_struct *p)
+static inline bool freezing(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 */
@@ -118,21 +105,27 @@ static inline int freezer_should_skip(struct task_struct *p)
}
/*
- * Tell the freezer that the current task should be frozen by it
+ * These macros are intended to be used whenever you want allow a task that's
+ * sleeping in TASK_UNINTERRUPTIBLE or TASK_KILLABLE state to be frozen. Note
+ * that neither return any clear indication of whether a freeze event happened
+ * while in this function.
*/
-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);
-}
+/* Like schedule(), but should not block the freezer. */
+#define freezable_schedule() \
+({ \
+ freezer_do_not_count(); \
+ schedule(); \
+ freezer_count(); \
+})
+
+/* Like schedule_timeout_killable(), but should not block the freezer. */
+#define freezable_schedule_timeout_killable(timeout) \
+({ \
+ freezer_do_not_count(); \
+ schedule_timeout_killable(timeout); \
+ freezer_count(); \
+})
/*
* Freezer-friendly wrappers around wait_event_interruptible(),
@@ -152,47 +145,51 @@ 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 bool frozen(struct task_struct *p) { return false; }
+static inline bool freezing(struct task_struct *p) { return false; }
+static inline void __thaw_task(struct task_struct *t) {}
-static inline void refrigerator(void) {}
+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 freezable_schedule() schedule()
+
+#define freezable_schedule_timeout_killable(timeout) \
+ schedule_timeout_killable(timeout)
#define wait_event_freezable(wq, condition) \
wait_event_interruptible(wq, condition)
diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 5cac19b3a266..0714b24c0e45 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -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);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1c4f3e9b9bc5..d81cce933869 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -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