Re: [PATCH 2/3 v2] futex: avoid double wake up in futex_wake() on -RT

[Thomas Gleixner]

On Thu, 16 Apr 2015, Peter Zijlstra wrote:

> On Thu, Apr 16, 2015 at 11:19:41AM +0200, Thomas Gleixner wrote:
> > So any code which does not handle a spurious wakeup is broken
> > independent of the futex changes. So really nothing to worry about.
> 
> Back when we did this:
> 
>  http://lkml.iu.edu/hypermail/linux/kernel/1109.1/01941.html
>  http://lkml.iu.edu/hypermail/linux/kernel/1109.1/01943.html
> 
> Things came apart -- notably sysvsems.
> 
> And yes its true that anything not dealing with spuriuos wakups is
> borken, but there's still quite a lot of borken out there, although I
> think we fixed all the really common ones.
> 
> But if we decide we want to go do this, I'd propose we reintroduce this
> delayed wake list thing again.

Indeed. Forgot about that completely.

Thanks,

	tglx
 
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