lkml.org 
[lkml]   [2016]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 05/11] mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED
From
Date
On 04/05/2016 01:25 PM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> try_to_compact_pages can currently return COMPACT_SKIPPED even when the
> compaction is defered for some zone just because zone DMA is skipped
> in 99% of cases due to watermark checks. This makes COMPACT_DEFERRED
> basically unusable for the page allocator as a feedback mechanism.
>
> Make sure we distinguish those two states properly and switch their
> ordering in the enum. This would mean that the COMPACT_SKIPPED will be
> returned only when all eligible zones are skipped.
>
> This shouldn't introduce any functional change.

Hmm, really? __alloc_pages_direct_compact() does distinguish
COMPACT_DEFERRED, and sets *deferred compaction, so ultimately this is
some change for THP allocations?

Also there's no mention of COMPACT_INACTIVE in the changelog (which
indeed isn't functional change, but might surprise somebody).

> Signed-off-by: Michal Hocko <mhocko@suse.com>

Patch itself is OK.

Acked-by: Vlastimil Babka <vbabka@suse.cz>

\
 
 \ /
  Last update: 2016-04-11 13:21    [W:0.183 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site