Re: [GIT PULL] Lockless SLUB slowpaths for v3.1-rc1

From: David Rientjes
Date: Mon Aug 08 2011 - 16:04:53 EST


On Wed, 3 Aug 2011, Christoph Lameter wrote:

> > The netperf benchmark isn't representative of a heavy slab consuming
> > workload, I routinely run jobs on these machines that use 20 times the
> > amount of slab. From what I saw in the earlier posting of the per-cpu
> > partial list patch, the min_partial value is set to half of what it was
> > previously as a per-node partial list. Since these are 16-core, 4 node
> > systems, that would mean that after a kmem_cache_shrink() on a cache that
> > leaves empty slab on the partial lists that we've doubled the memory for
> > slub's partial lists systemwide.
>
> Cutting down the potential number of empty slabs that we might possible
> keep around because we have no partial slabs per node increases memory
> usage?
>

You halved the number of min_partial, but there are 16 partial lists on
these machines because they are per-cpu instead of 4 partial lists when
they were per-node.
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