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| author | Tejun Heo <tj@kernel.org> | 2011-11-21 12:32:24 -0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2011-11-21 12:32:24 -0800 |
| commit | 85f1d476653f52c97ca75466b2494e67c1cbd25d (patch) | |
| tree | a1839143272cc4e6593e5d4c97e8a3c39aed08ff /kernel/freezer.c | |
| parent | 6907483b4e803a20f0b48cc9afa3817420ce61c5 (diff) | |
| download | linux-stable-85f1d476653f52c97ca75466b2494e67c1cbd25d.tar.gz linux-stable-85f1d476653f52c97ca75466b2494e67c1cbd25d.tar.bz2 linux-stable-85f1d476653f52c97ca75466b2494e67c1cbd25d.zip | |
freezer: test freezable conditions while holding freezer_lock
try_to_freeze_tasks() and thaw_processes() use freezable() and
frozen() as preliminary tests before initiating operations on a task.
These are done without any synchronization and hinder with
synchronization cleanup without any real performance benefits.
In try_to_freeze_tasks(), open code self test and move PF_NOFREEZE and
frozen() tests inside freezer_lock in freeze_task().
thaw_processes() can simply drop freezable() test as frozen() test in
__thaw_task() is enough.
Note: This used to be a part of larger patch to fix set_freezable()
race. Separated out to satisfy ordering among dependent fixes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Diffstat (limited to 'kernel/freezer.c')
| -rw-r--r-- | kernel/freezer.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/freezer.c b/kernel/freezer.c index a8822be43da0..a257ecd37c48 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -109,7 +109,8 @@ bool freeze_task(struct task_struct *p, bool sig_only) spin_lock_irqsave(&freezer_lock, flags); - if (sig_only && !should_send_signal(p)) + if ((p->flags & PF_NOFREEZE) || + (sig_only && !should_send_signal(p))) goto out_unlock; if (frozen(p)) |