Re: [patch] possible SMP races all over the place in wait_event

Linus Torvalds (torvalds@transmeta.com)
Mon, 16 Aug 1999 10:27:07 -0700 (PDT)

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On Mon, 16 Aug 1999, Andrea Arcangeli wrote:
>
> Maybe I am dreaming, but it seems to me that the wait_even interface has
> SMP races. To make it SMP safe we should enforce read and write ordering
> in the wait_event code.

The spinlocks and atomic operations implied by "wake_up()" and company
make this a non-issue: a spinlock has to guarantee write ordering anyway,
otherwise it wouldn't be an effective spinlock..

So about half of your patch is unnecessary, but the latter half looks
valid.

Linus

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