Re: [PATCH 0/4] Follow-up "Fix excessive CPU usage during compaction"

Mel Gorman
2023-05-21T19:21:03Z

On Fri, May 19, 2023 at 12:13:11PM +0530, Raghavendra K T wrote:
> On 5/15/2023 5:03 PM, Mel Gorman wrote:
> > The series "Fix excessive CPU usage during compaction" [1] attempted to
> > fix a bug [2] but Vlastimil noted that the fix was incomplete [3]. While
> > the series was merged, fast_find_migrateblock was still disabled. This
> > series should fix the corner cases and allow 95e7a450b819 ("Revert
> > "mm/compaction: fix set skip in fast_find_migrateblock"") to be safely
> > reverted. Details on how many pageblocks are rescanned are in the
> > changelog of the last patch.
> >
> > [1] https://lore.kernel.org/r/20230125134434.18017-1-mgorman@techsingularity.net
> > [2] https://bugzilla.suse.com/show_bug.cgi?id=1206848
> > [3] https://lore.kernel.org/r/a55cf026-a2f9-ef01-9a4c-398693e048ea@suse.cz
> >
> > mm/compaction.c | 24 ++++++++++--------------
> > 1 file changed, 10 insertions(+), 14 deletions(-)
> >
>
> Hello Mel,
>
> Not sure how much this info would help, (also I saw it is in Andrew's
> tree already) But was curious to evaluate the patchset from perf
> perspective, and I have run mmtest usemem so here is the result (Only
> for compact cases).
>
> <SNIP>
>

Thanks Raghavendra!

--
Mel Gorman
SUSE Labs