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Subject: Re: hackbench regression due to commit 9dfc6e68bfe6e
From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>,
       Pekka Enberg <penberg@cs.helsinki.fi>, netdev <netdev@vger.kernel.org>,
       Tejun Heo <tj@kernel.org>, alex.shi@intel.com,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "Ma, Ling" <ling.ma@intel.com>, "Chen, Tim C" <tim.c.chen@intel.com>,
       Andrew Morton <akpm@linux-foundation.org>
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Date: Thu, 08 Apr 2010 09:05:47 +0800
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On Wed, 2010-04-07 at 20:38 +0200, Eric Dumazet wrote:
> Le mercredi 07 avril 2010 à 13:20 -0500, Christoph Lameter a écrit :
> > On Wed, 7 Apr 2010, Pekka Enberg wrote:
> > 
> > > Oh, sorry, I think it's actually '____cacheline_aligned_in_smp' (with four
> > > underscores) for per-cpu data. Confusing...
> > 
> > This does not particulary help to clarify the situation since we are
> > dealing with data that can either be allocated via the percpu allocator or
> > be statically present (kmalloc bootstrap situation).
> > 
> > --
> 
> Do we have a user program to check actual L1 cache size of a machine ?
If there is no, it's easy to write it as kernel exports the cache stat by
/sys/devices/system/cpu/cpuXXX/cache/indexXXX/

> 
> I remember my HP blades have many BIOS options, I would like to make
> sure they are properly set.
> 
> 
>