Re: [PATCH v2 00/10] try to reduce fragmenting fallbacks

Mel Gorman
2017-02-13T11:07:06Z

On Fri, Feb 10, 2017 at 06:23:33PM +0100, Vlastimil Babka wrote:
> Hi,
>
> this is a v2 of [1] from last year, which was a response to Johanes' worries
> about mobility grouping regressions. There are some new patches and the order
> goes from cleanups to "obvious wins" towards "just RFC" (last two patches).
> But it's all theoretical for now, I'm trying to run some tests with the usual
> problem of not having good workloads and metrics :) But I'd like to hear some
> feedback anyway. For now this is based on v4.9.
>
> I think the only substantial new patch is 08/10, the rest is some cleanups,
> small tweaks and bugfixes.
>

By and large, I like the series, particularly patches 7 and 8. I cannot
make up my mind about the RFC patches 9 and 10 yet. Conceptually they
seem sound but they are much more far reaching than the rest of the
series.

It would be nice if patches 1-8 could be treated in isolation with data
on the number of extfrag events triggered, time spent in compaction and
the success rate. Patches 9 and 10 are tricy enough that they would need
data per patch where as patches 1-8 should be ok with data gathered for
the whole series.

--
Mel Gorman
SUSE Labs