Re: SLUB performance regression vs SLAB

From: Christoph Lameter
Date: Thu Oct 04 2007 - 13:50:09 EST


On Thu, 4 Oct 2007, Matthew Wilcox wrote:

> > Yeah the fastpath vs. slow path is not the issue as Siddha and I concluded
> > earlier. Seems that we are mainly seeing cacheline bouncing due to two
> > cpus accessing meta data in the same page struct. The patches in
> > MM that are scheduled to be merged for .24 address that issue. I
> > have repeatedly asked that these patches be tested. The patches were
> > posted months ago.
>
> I just checked with the guys who did the test. When I said -rc3, I
> mis-spoke; this is 2.6.23-rc3 *plus* the patches which Suresh agreed to
> test for you.

I was not aware of that. Would it be possible for you to summarize all the
test data that you have right now about SLUB vs. SLAB with the patches
listed? Exactly what kernel version and what version of the per cpu
patches were tested? Was the page allocator pass through patchset
separately applied as I requested?

Finally: Is there some way that I can reproduce the tests on my machines?
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