Re: [PATCH] online CPU before memory failed in pcpu_alloc_pages()

[KAMEZAWA Hiroyuki]

On Fri, 21 May 2010 10:55:12 +1000
Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:

> Hi Andrew,
> 
> On Thu, 20 May 2010 13:43:59 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > > --- a/mm/percpu.c
> > > +++ b/mm/percpu.c
> > > @@ -714,13 +714,29 @@ static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
> > 
> > In linux-next, Tejun has gone and moved pcpu_alloc_pages() into the new
> > mm/percpu-vm.c.  So either
> 
> This has gone into Linus' tree today ...
> 

Hmm, a comment here.

Recently, Lee Schermerhorn developed

 numa-introduce-numa_mem_id-effective-local-memory-node-id-fix2.patch

Then, you can use cpu_to_mem() instead of cpu_to_node() to find the
nearest available node.
I don't check cpu_to_mem() is synchronized with NUMA hotplug but
using cpu_to_mem() rather than adding 
=

+			if ((nid == -1) ||
+			    !(node_zonelist(nid, GFP_KERNEL)->_zonerefs->zone))
+				nid = numa_node_id();
+
==

is better. 

Thanks,
-Kame

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