Re: [patch] mm, slab: faster active and free stats

From: Andrew Morton
Date: Tue Nov 08 2016 - 18:17:32 EST


On Tue, 8 Nov 2016 15:06:45 -0800 (PST) David Rientjes <rientjes@xxxxxxxxxx> wrote:

> Reading /proc/slabinfo or monitoring slabtop(1) can become very expensive
> if there are many slab caches and if there are very lengthy per-node
> partial and/or free lists.
>
> Commit 07a63c41fa1f ("mm/slab: improve performance of gathering slabinfo
> stats") addressed the per-node full lists which showed a significant
> improvement when no objects were freed. This patch has the same
> motivation and optimizes the remainder of the usecases where there are
> very lengthy partial and free lists.
>
> This patch maintains per-node active_slabs (full and partial) and
> free_slabs rather than iterating the lists at runtime when reading
> /proc/slabinfo.

Are there any nice numbers you can share?