Re: REGRESSION: Performance regressions from switching anon_vma->lockto mutex

From: Linus Torvalds
Date: Fri Jun 17 2011 - 12:49:34 EST


On Fri, Jun 17, 2011 at 4:28 AM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>
> Something like so? Compiles and runs the benchmark in question.

Oh, and can you do this with a commit log and sign-off, and I'll put
it in my "anon_vma-locking" branch that I have. I'm not going to
actually merge that branch into mainline until I've seen a few more
acks or more testing by Tim.

But if Tim's numbers hold up (-32% to +15% performance by just the
first one, and +15% isn't actually an improvement since tmpfs
read-ahead should have gotten us to +66%), I think we have to do this
just to avoid the performance regression.

Linus
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