Re: mmotm woes, mainly compaction

[Vlastimil Babka <vbabka@suse.cz>]

On 04/12/2016 09:18 AM, Hugh Dickins wrote:
> 3. /proc/sys/vm/stat_refresh warns nr_isolated_anon and nr_isolated_file
>     go increasingly negative under compaction: which would add delay when
>     should be none, or no delay when should delay.  putback_movable_pages()
>     decrements the NR_ISOLATED counts which acct_isolated() increments,
>     so isolate_migratepages_block() needs to acct before putback in that
>     special case, and isolate_migratepages_range() can always do the acct
>     itself, leaving migratepages putback to caller like most other places.

The isolate_migratepages_block() part is mmotm-specific, so I'll split
it out in this patch. Thanks for catching it and the lack of reset for
cc->nr_migratepages which wasn't mentioned in changelog so I added it.
 
> 5. It's easier to track the life of cc->migratepages if we don't assign
>     it to a migratelist variable.

This is also included here.

This is a -fix for:
mm-compaction-skip-blocks-where-isolation-fails-in-async-direct-compaction.patch

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