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| author | Thomas Gleixner <tglx@linutronix.de> | 2009-07-17 12:15:47 (GMT) |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2009-07-18 12:19:53 (GMT) |
| commit | 6301cb95c119ebf324bb96ee226fa9ddffad80a7 (patch) | |
| tree | 7201f406d135212bae3775dc7d71cbdd6990e5de | |
| parent | a468d389349a7560249b355cdb6d2097ea1616c9 (diff) | |
| download | linux-fsl-qoriq-6301cb95c119ebf324bb96ee226fa9ddffad80a7.tar.xz | |
sched: fix nr_uninterruptible accounting of frozen tasks really
commit e3c8ca8336 (sched: do not count frozen tasks toward load) broke
the nr_uninterruptible accounting on freeze/thaw. On freeze the task
is excluded from accounting with a check for (task->flags &
PF_FROZEN), but that flag is cleared before the task is thawed. So
while we prevent that the task with state TASK_UNINTERRUPTIBLE
is accounted to nr_uninterruptible on freeze we decrement
nr_uninterruptible on thaw.
Use a separate flag which is handled by the freezing task itself. Set
it before calling the scheduler with TASK_UNINTERRUPTIBLE state and
clear it after we return from frozen state.
Cc: <stable@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/freezer.c | 7 |
2 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 16a982e..3ab08e4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -209,7 +209,7 @@ extern unsigned long long time_sync_thresh; ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) #define task_contributes_to_load(task) \ ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \ - (task->flags & PF_FROZEN) == 0) + (task->flags & PF_FREEZING) == 0) #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) @@ -1680,6 +1680,7 @@ extern cputime_t task_gtime(struct task_struct *p); #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_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 */ diff --git a/kernel/freezer.c b/kernel/freezer.c index 2f4936c..bd1d42b 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -44,12 +44,19 @@ void refrigerator(void) recalc_sigpending(); /* We sent fake signal, clean it up */ spin_unlock_irq(¤t->sighand->siglock); + /* prevent accounting of that task to load */ + current->flags |= PF_FREEZING; + for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); if (!frozen(current)) break; schedule(); } + + /* Remove the accounting blocker */ + current->flags &= ~PF_FREEZING; + pr_debug("%s left refrigerator\n", current->comm); __set_current_state(save); } |