Messages in this thread | | | Date | Mon, 27 Jun 2022 11:59:50 +0800 | Subject | Re: [PATCH 4/7] migrate_pages(): fix failure counting for THP subpages retrying | From | Baolin Wang <> |
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On 6/27/2022 9:46 AM, Huang, Ying wrote: > Baolin Wang <baolin.wang@linux.alibaba.com> writes: > >> On 6/24/2022 10:53 AM, Huang Ying wrote: >>> If THP is failed to be migrated for -ENOSYS and -ENOMEM, the THP will >>> be split into thp_split_pages, and after other pages are migrated, >>> pages in thp_split_pages will be migrated with no_subpage_counting == >>> true, because its failure have been counted already. If some pages in >>> thp_split_pages are retried during migration, we should not count >>> their failure if no_subpage_counting == true too. This is done this >>> patch to fix the failure counting for THP subpages retrying. >> >> Good catch. Totally agree with you. It seems we can move the condition >> into -EAGAIN case like other cases did? >> >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 1ece23d80bc4..491c2d07402b 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -1463,7 +1463,7 @@ int migrate_pages(struct list_head *from, >> new_page_t get_new_page, >> case -EAGAIN: >> if (is_thp) >> thp_retry++; >> - else >> + else if (!no_subpage_counting) >> retry++; >> break; > > This has another effect except fixing the failure counting. That is, > the split subpages of THP will not be retried for 10 times for -EAGAIN.
Ah, yes.
> TBH, I think that we should do that. But because this has some behavior
OK. So you afraid that 10 times retry for each subpage of THP will waste lots of time?
> change, it's better to be done in a separate patch? Do you have > interest to do that on top of this patchset?
Sure. I can send a patch which can be folded into your series. Is this OK for you?
By the way, if I do like I said, the patch 4 can be avoided.
> >> Anyway this patch looks good to me. >> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> > > Thanks! > > Best Regards, > Huang, Ying > >>> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> >>> Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") >>> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> >>> Cc: Zi Yan <ziy@nvidia.com> >>> Cc: Yang Shi <shy828301@gmail.com> >>> --- > mm/migrate.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> diff --git a/mm/migrate.c b/mm/migrate.c >>> index 542533e4e3cf..61dab3025a1d 100644 >>> --- a/mm/migrate.c >>> +++ b/mm/migrate.c >>> @@ -1477,7 +1477,8 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, >>> } >>> } >>> } >>> - nr_failed += retry; >>> + if (!no_subpage_counting) >>> + nr_failed += retry; >>> nr_thp_failed += thp_retry; >>> /* >>> * Try to migrate subpages of fail-to-migrate THPs, no nr_failed
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