Date: Wed, 26 Nov 2008 19:37:17 -0600 (CST)
From: Christoph Lameter <cl@linux-foundation.org>
To: Eric Dumazet <dada1@cosmosbay.com>
cc: Ingo Molnar <mingo@elte.hu>, David Miller <davem@davemloft.net>,
       "Rafael J. Wysocki" <rjw@sisk.pl>, linux-kernel@vger.kernel.org,
       kernel-testers@vger.kernel.org, Mike Galbraith <efault@gmx.de>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Linux Netdev List <netdev@vger.kernel.org>,
       Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 0/6] fs: Scalability of sockets/pipes allocation/deallocation
 on SMP
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On Thu, 27 Nov 2008, Eric Dumazet wrote:

> The last point is about SLUB being hit hard, unless we
> use slub_min_order=3 at boot, or we use Christoph Lameter
> patch (struct file RCU optimizations)
> http://thread.gmane.org/gmane.linux.kernel/418615
>
> If we boot machine with slub_min_order=3, SLUB overhead disappears.


I'd rather not be that drastic. Did you try increasing slub_min_objects
instead? Try 40-100. If we find the right number then we should update
the tuning to make sure that it pickes the right slab page sizes.
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