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From: "Duyck, Alexander H" <alexander.h.duyck@intel.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: RE: [PATCH] slub: move kmem_cache_node into it's own cacheline
Date: Fri, 21 May 2010 11:17:51 -0700	[thread overview]
Message-ID: <80769D7B14936844A23C0C43D9FBCF0F256284AECC@orsmsx501.amr.corp.intel.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1005211305340.14851@router.home>

Christoph Lameter wrote:
> On Thu, 20 May 2010, Alexander Duyck wrote:
> 
>> diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
>> index 0249d41..e6217bb 100644 --- a/include/linux/slub_def.h
>> +++ b/include/linux/slub_def.h
>> @@ -52,7 +52,7 @@ struct kmem_cache_node {
>>  	atomic_long_t total_objects;
>>  	struct list_head full;
>>  #endif
>> -};
>> +} ____cacheline_internodealigned_in_smp;
> 
> What does this do? Leftovers?

It aligns it to the correct size so that no two instances can occupy a shared cacheline.  I put that in place to avoid any false sharing of the objects should they fit into a shared cacheline on a NUMA system.

Thanks,

Alex
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  reply	other threads:[~2010-05-21 18:17 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-20 23:47 Alexander Duyck
2010-05-21  4:59 ` Pekka Enberg
2010-05-21 14:41   ` Shi, Alex
2010-05-21 18:03     ` Christoph Lameter
2010-05-24 18:14     ` Pekka Enberg
2010-05-26  0:52       ` Shi, Alex
2010-05-21 18:06 ` Christoph Lameter
2010-05-21 18:17   ` Duyck, Alexander H [this message]
2010-05-21 18:24     ` Christoph Lameter
2010-05-21 18:33       ` Christoph Lameter
2010-05-21 20:23         ` Duyck, Alexander H
2010-05-21 20:41           ` Christoph Lameter

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