Re: hackbench regression since 2.6.25-rc

From: Christoph Lameter
Date: Mon Mar 17 2008 - 13:28:22 EST


On Mon, 17 Mar 2008, Zhang, Yanmin wrote:

> There is no much help. In 2.6.25-rc5, REFILL means refill from c->page->freelist
> and another_slab. It's looks like its definition is confusing. In the case of
> hackbench, mostly, c->page->freelist is NULL.

REFILL means refilling the per cpu objects from the freelist of the
per cpu slab page. That could be bad because it requires taking the slab
lock on the slab page.

> Slab Perf Counter Alloc Free %Al %Fr
> --------------------------------------------------
> Fastpath 55883575 6130576 69 7
> Slowpath 24131134 73883818 30 92
> Page Alloc 84844 84788 0 0
> Add partial 270625 23860257 0 29
> Remove partial 24046290 84752 30 0

Hmmm... I was hoping that add/remove partial numbers would come down. Ok
lets forget about the patch. Increasing min_objects does the trick.
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