Date: Thu, 12 Sep 2013 14:16:58 +0000
From: Christoph Lameter <cl@linux.com>
To: Dave Hansen <dave@sr71.net>
cc: Cody P Schafer <cody@linux.vnet.ibm.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] mm: percpu pages: up batch size to fix arithmetic??
 errror
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On Wed, 11 Sep 2013, Dave Hansen wrote:

> 3. We want ->high to approximate the size of the cache which is
>    private to a given cpu.  But, that's complicated by the L3 caches
>    and hyperthreading today.

well lets keep it well below that. There are other caches (slab related
f.e.) that are also in constant use.

> I'll take one of my big systems and run it with some various ->high
> settings and see if it makes any difference.

Do you actually see contention issues on the locks? I think we have a
tendency to batch too much in too many caches.


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