Re: [GIT PULL] Re: REGRESSION: Performance regressions from switching anon_vma->lock to mutex

Paul E. McKenney
2011-06-15T21:15:35Z

On Wed, Jun 15, 2011 at 02:05:46PM -0700, Linus Torvalds wrote:
>
>
> Ingo Molnar <mingo@elte.hu> wrote:
> >
> >I have this fix queued up currently:
> >
> > 09223371deac: rcu: Use softirq to address performance regression
>
> I really don't think that is even close to enough.
>
> It still does all the callbacks in the threads, and according to Peter, about half the rcu time in the threads remained..

I am putting together a patch that gets rid of the kthreads in the
!RCU_BOOST case. The time will still be consumed, but in softirq
context, though of course with many fewer context switches.

Thanx, Paul