On 2022/7/12 15:27, Zhou Chuyi wrote:
> From: zhouchuyi <zhouchuyi@xxxxxxxxxxxxx>
>
> When we successfully find a pageblock in
> fast_find_migrateblock(), the block will be set
> skip-flag through set_pageblock_skip().
> However, when entering isolate_migratepages_block(),
> the whole pageblock will be skipped due to the branch
> 'if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages))'.
> Eventually we will goto isolate_abort and isolate nothing.
> That cause fast_find_migrateblock useless.
>
> In this Patch, when we find a suitable pageblock in
> fast_find_migrateblock, we do noting but let
> isolate_migratepages_block to set skip flag to
> the pageblock after scan it. Normally, we would
> isolate some pages from the fast-find block.
>
> I use mmtest/thpscale-madvhugepage test it. Here
> is the result:
> baseline patch
> Amean fault-both-1 1331.66 ( 0.00%) 1261.04 * 5.30%*
> Amean fault-both-3 1383.95 ( 0.00%) 1191.69 * 13.89%*
> Amean fault-both-5 1568.13 ( 0.00%) 1445.20 * 7.84%*
> Amean fault-both-7 1819.62 ( 0.00%) 1555.13 * 14.54%*
> Amean fault-both-12 1106.96 ( 0.00%) 1149.43 * -3.84%*
> Amean fault-both-18 2196.93 ( 0.00%) 1875.77 * 14.62%*
> Amean fault-both-24 2642.69 ( 0.00%) 2671.21 * -1.08%*
> Amean fault-both-30 2901.89 ( 0.00%) 2857.32 * 1.54%*
> Amean fault-both-32 3747.00 ( 0.00%) 3479.23 * 7.15%*
>
> Fixs: 'commit 70b44595eafe9 ("mm, compaction: use free lists
> to quickly locate a migration source")'
Thanks for your patch. Yet something to improve:
./scripts/checkpatch.pl v2-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch
ERROR: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 70b44595eafe ("mm, compaction: use free lists to quickly locate a migration source")'
#101:
Fixs: 'commit 70b44595eafe9 ("mm, compaction: use free lists
to quickly locate a migration source")'
total: 1 errors, 0 warnings, 7 lines checked
NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.
[PATCH v2] mm_compaction fix set skip in fast_find_migrateblock.eml has style problems, please review.
NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
And remember runing get_maintainer.pl to get the right people before sending the patch:
./scripts/get_maintainer.pl v2-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> (maintainer:MEMORY MANAGEMENT)
linux-mm@xxxxxxxxx (open list:MEMORY MANAGEMENT)
linux-kernel@xxxxxxxxxxxxxxx (open list)
BTW: It's not enforced but ~70 chars per line in commit log might be preferred.
>
> Signed-off-by: zhouchuyi <zhouchuyi@xxxxxxxxxxxxx>
Thanks.
> ---
> mm/compaction.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/mm/compaction.c b/mm/compaction.c
> index 1f89b969c..a1a2b50c8 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -1852,7 +1852,6 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc)
> pfn = cc->zone->zone_start_pfn;
> cc->fast_search_fail = 0;
> found_block = true;
> - set_pageblock_skip(freepage);
> break;
> }
> }
>
