Re: [PATCH] Fix page_group_by_mobility_disabled breakage

From: Mel Gorman
Date: Wed Oct 30 2013 - 11:25:21 EST

On Fri, Oct 25, 2013 at 02:09:35PM -0400, kosaki.motohiro@xxxxxxxxx wrote:
> From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> Currently, set_pageblock_migratetype screw up MIGRATE_CMA and
> MIGRATE_ISOLATE if page_group_by_mobility_disabled is true. It
> rewrite the argument to MIGRATE_UNMOVABLE and we lost these attribute.
> The problem was introduced commit 49255c619f (page allocator: move
> check for disabled anti-fragmentation out of fastpath). So, 4 years
> lived issue may mean that nobody uses page_group_by_mobility_disabled.

Nobody uses page_group_by_mobility_disabled with CMA at least.
page_group_by_mobility_disabled only kicks in automatically for small
machines so it's possible the condition is very rarely encountered.


Acked-by: Mel Gorman <mgorman@xxxxxxx>

Mel Gorman
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