Hi, Baolin, Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> writes: > If THP is failed to migrate due to -ENOSYS or -ENOMEM case, the THP will > be split, and the subpages of fail-to-migrate THP will be tried to migrate > again, so we should not account the retry counter in the second loop, since > we already accounted 'nr_thp_failed' in the first loop. > > Moreover we also do not need retry 10 times for -EAGAIN case for the subpages > of fail-to-migrate THP in the second loop, since we already regarded the > THP as migration failure, and save some migration time (for the worst case, > will try 512 * 10 times) according to previous discussion [1]. > > [1] https://lore.kernel.org/linux-mm/87r13a7n04.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> I have tested this patch, and it works as expected. Tested-by: "Huang, Ying" <ying.huang@xxxxxxxxx> > --- > Note, this patch is based on the patch set [1] from Huang Ying. > [1] https://lore.kernel.org/linux-mm/20220711084948.274787-1-ying.huang@xxxxxxxxx/ Please this patch is based on my patchset that hasn't been merged. I can add it as the last patch of my migrate_pages failure path fixing patchset if you don't object. Best Regards, Huang, Ying > --- > mm/migrate.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 8429206..e36a084 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1507,7 +1507,7 @@ 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++; > nr_retry_pages += nr_subpages; > break; > @@ -1533,8 +1533,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > } > } > } > - if (!no_subpage_counting) > - nr_failed += retry; > + nr_failed += retry; > nr_thp_failed += thp_retry; > nr_failed_pages += nr_retry_pages; > /*
