Re: Add memory barrier when waiting on futex

[Peter Zijlstra]

On Tue, Nov 26, 2013 at 01:07:25AM +0000, Ma, Xindong wrote:
> I've already aware that they've protected by spinlock, this is why I adding a memory barrier to fix it.

That doesn't make sense.. the spinlocks should provide the required
serialization, there's nothing to fix.

> I reproduced this issue several times on android which running on IA dual core.

I think you need to be more specific, in particular, if spinlocks do not
provide serialization on your IA32 device, I'd call that thing broken.
Adding random memory barriers is _WRONG_.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/