From: Christoph Lameter <cl@linux.com>
To: Tejun Heo <tj@kernel.org>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
linux-mm@kvack.org, linux-numa@vger.kernel.org,
Mel Gorman <mel@csn.ul.ie>,
andi@firstfloor.org, Nick Piggin <npiggin@suse.de>,
David Rientjes <rientjes@google.com>,
eric.whitney@hp.com, Andrew Morton <akpm@linux-foundation.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [PATCH 2/8] numa: x86_64: use generic percpu var numa_node_id() implementation
Date: Sat, 1 May 2010 20:49:41 -0500 (CDT) [thread overview]
Message-ID: <alpine.DEB.2.00.1005012048220.2663@router.home> (raw)
In-Reply-To: <4BDA6362.4030505@kernel.org>
On Fri, 30 Apr 2010, Tejun Heo wrote:
> Hello,
>
> On 04/29/2010 06:56 PM, Lee Schermerhorn wrote:
> > Tejun: do you mean:
> >
> > #ifdef CONFIG_NUMA
> > if (cpu != 0 && percpu_read(numa_node) == 0 &&
> > ........................^ here?
> > early_cpu_to_node(cpu) != NUMA_NO_NODE)
> > set_numa_node(early_cpu_to_node(cpu));
> > #endif
> >
> > Looks like 'numa_node_id()' would work there.
>
> Yeah, it just looked weird to use raw variable when an access wrapper
> is there.
>
> > But, I wonder what the "cpu != 0 && percpu_read(numa_node) == 0" is
> > trying to do?
>
> That I have don't have any clue about. :-)
I guess that cpu 0 is used for booting and its initialized early when
certain functionality is not available yet.
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next prev parent reply other threads:[~2010-05-02 1:53 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-15 17:29 [PATCH 0/8] Numa: Use Generic Per-cpu Variables for numa_*_id() Lee Schermerhorn
2010-04-15 17:29 ` [PATCH 1/8] numa: add generic percpu var numa_node_id() implementation Lee Schermerhorn
2010-04-16 16:43 ` Christoph Lameter
2010-04-16 20:33 ` Andrew Morton
2010-04-19 13:22 ` Lee Schermerhorn
2010-04-19 2:32 ` KAMEZAWA Hiroyuki
2010-04-15 17:30 ` [PATCH 2/8] numa: x86_64: use " Lee Schermerhorn
2010-04-16 16:46 ` Christoph Lameter
2010-04-18 2:56 ` Tejun Heo
2010-04-29 16:56 ` Lee Schermerhorn
2010-04-30 4:58 ` Tejun Heo
2010-05-02 1:49 ` Christoph Lameter [this message]
2010-04-15 17:30 ` [PATCH 3/8] numa: ia64: " Lee Schermerhorn
2010-04-19 2:51 ` KAMEZAWA Hiroyuki
2010-04-15 17:30 ` [PATCH 4/8] numa: Introduce numa_mem_id()- effective local memory node id Lee Schermerhorn
2010-04-18 3:13 ` Tejun Heo
2010-04-15 17:30 ` [PATCH 5/8] numa: ia64: support numa_mem_id() for memoryless nodes Lee Schermerhorn
2010-04-18 3:14 ` Tejun Heo
2010-04-15 17:30 ` [PATCH 6/8] numa: slab: use numa_mem_id() for slab local memory node Lee Schermerhorn
2010-05-12 18:49 ` Andrew Morton
2010-05-12 19:11 ` Lee Schermerhorn
2010-05-12 19:25 ` Valdis.Kletnieks
2010-05-12 20:03 ` Lee Schermerhorn
2010-04-15 17:30 ` [PATCH 7/8] numa: in-kernel profiling: use cpu_to_mem() for per cpu allocations Lee Schermerhorn
2010-04-15 17:30 ` [PATCH 8/8] numa: update Documentation/vm/numa, add memoryless node info Lee Schermerhorn
2010-04-15 18:00 ` Randy Dunlap
2010-04-16 0:50 ` KAMEZAWA Hiroyuki
2010-04-18 3:19 ` [PATCH 0/8] Numa: Use Generic Per-cpu Variables for numa_*_id() Tejun Heo
2010-04-19 13:29 ` Lee Schermerhorn
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