Re: [patch] shaper fix for timer SMP races

Ingo Molnar (mingo@chiara.csoma.elte.hu)
Wed, 17 Feb 1999 15:59:06 +0100 (CET)


On Wed, 17 Feb 1999, Andrea Arcangeli wrote:

> >> + start_bh_atomic();
> >> del_timer(&shaper->timer);
> >> + end_bh_atomic();

> shaper->timer running on the other CPU while you are deleting it. Yes, the
> timerlist is preserved from corruption, but you may remove the vmalloced
> module code while the shaper->timer is running.

then it's enough to do this:

+ del_timer(&shaper->timer);
+ synchronize_bh(); /* wait for module code to be unused */

your fix is confusing otherwise.

-- mingo

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