Re: mmotm woes, mainly compaction

[Vlastimil Babka]

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.

Sigh, looks like I notoriously suck at the nr_isolated_* accounting. The
isolate_migratepages_range() is also due to my 3.18 commit. Back then,
Joonsoo caught the problem for compaction side, but CMA issue remains.
Sorry and thanks.

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