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| author | Tejun Heo <tj@kernel.org> | 2011-11-21 20:32:23 (GMT) |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2011-11-21 20:32:23 (GMT) |
| commit | a585042f7b933539a0b6bc63650c2d49ffb2e55d (patch) | |
| tree | bb93d05050e04c4bcd53fdf535239e6312fb62e2 /kernel | |
| parent | a5be2d0d1a8746e7be5210e3d6b904455000443c (diff) | |
| download | linux-a585042f7b933539a0b6bc63650c2d49ffb2e55d.tar.xz | |
freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks
clear_freeze_flag() in exit_mm() is racy. Freezing can start
afterwards. Remove it. Skipping freezer for exiting task will be
properly implemented later.
Also, freezable() was testing exit_state directly to make system
freezer ignore dead tasks. Let the exiting task set PF_NOFREEZE after
entering TASK_DEAD instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 3 | ||||
| -rw-r--r-- | kernel/power/process.c | 3 |
2 files changed, 2 insertions, 4 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index d0b7d98..95a4141 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -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". */ diff --git a/kernel/power/process.c b/kernel/power/process.c index fe27872..23822dc 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -25,8 +25,7 @@ static inline int freezable(struct task_struct * p) { if ((p == current) || - (p->flags & PF_NOFREEZE) || - (p->exit_state != 0)) + (p->flags & PF_NOFREEZE)) return 0; return 1; } |