Messages in this thread | | | Subject | Re: [PATCH v2 5/9] mm/compaction: allow to scan nonmovable pageblock when depleted state | From | Vlastimil Babka <> | Date | Fri, 25 Sep 2015 12:32:02 +0200 |
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On 08/24/2015 04:19 AM, Joonsoo Kim wrote:
[...]
> > Because we just allow freepage scanner to scan non-movable pageblock > in very limited situation, more scanning events happen. But, allowing > in very limited situation results in a very important benefit that > memory isn't fragmented more than before. Fragmentation effect is > measured on following patch so please refer it.
AFAICS it's measured only for the whole series in the cover letter, no? Just to be sure I didn't overlook something.
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> > --- > include/linux/mmzone.h | 1 + > mm/compaction.c | 27 +++++++++++++++++++++++++-- > 2 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index e13b732..5cae0ad 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -545,6 +545,7 @@ enum zone_flags { > */ > ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */ > ZONE_COMPACTION_DEPLETED, /* compaction possiblity depleted */ > + ZONE_COMPACTION_SCANALLFREE, /* scan all kinds of pageblocks */
"SCANALLFREE" is hard to read. Otherwise yeah, I agree scanning unmovable pageblocks is necessary sometimes, and this seems to make a reasonable tradeoff.
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