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Freezer: Use SMP barriers

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The freezer processes are dealing with multiple threads running
simultaneously, and on a UP system, the memory reads/writes do
not need barriers to keep things in sync.  These are only needed
on SMP systems, so use SMP barriers instead.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Mike Frysinger 2011-04-25 12:33:15 +02:00 committed by Rafael J. Wysocki
parent 3c43193608
commit ee940d8dcc
1 changed files with 2 additions and 2 deletions
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4
kernel/freezer.c
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@ -17,7 +17,7 @@ static inline void frozen_process(void)
{
if (!unlikely(current->flags & PF_NOFREEZE)) {
current->flags |= PF_FROZEN;
wmb();
smp_wmb();
}
clear_freeze_flag(current);
}
@ -93,7 +93,7 @@ bool freeze_task(struct task_struct *p, bool sig_only)
* the task as frozen and next clears its TIF_FREEZE.
*/
if (!freezing(p)) {
rmb();
smp_rmb();
if (frozen(p))
return false;