Re: [PATCH] increase PREEMPT_BITS to 12 to avoid overflow whenstarting KVM

From: Peter Zijlstra
Date: Tue Mar 30 2010 - 14:34:58 EST


On Tue, 2010-03-30 at 14:05 -0400, Rik van Riel wrote:
> > Also, you'll need to convince mingo and tglx too.. taking that many
> > spinlocks is utter suckage..
>
> No argument there. I can't think of an alternative to mm_take_all_locks
> though. Andrea?

Well there's altneratives enough, back when this got introduces quite a
few got mentioned too, but they all make the !mm_take_all_locks() lock
side slower so Andrea didn't like them.

I think one of them got mentioned in yesterday's thread as well.

Another alternative is making all those spinlocks mutexes, that will get
rid of that massive !preempt section too.

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