Re: [PATCH 4/4] alloc_contig_pages() use better allocation functionfor migration

[Minchan Kim]

On Fri, Nov 19, 2010 at 5:16 PM, KAMEZAWA Hiroyuki
<kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
>
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>
> Old story.
> Because we cannot assume which memory section will be offlined next,
> hotremove_migrate_alloc() just uses alloc_page(). i.e. make no decision
> where the page should be migrate into. Considering memory hotplug's
> nature, the next memory section near to a section which is being removed
> will be removed in the next. So, migrate pages to the same node of original
> page doesn't make sense in many case, it just increases load.
> Migration destination page is allocated from the node where offlining script
> runs.
>
> Now, contiguous-alloc uses do_migrate_range(). In this case, migration
> destination node should be the same node of migration source page.
>
> This patch modifies hotremove_migrate_alloc() and pass "nid" to it.
> Memory hotremove will pass -1. So, if the page will be moved to
> the node where offlining script runs....no behavior changes.
>
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>


-- 
Kind regards,
Minchan Kim
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