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> --- 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/ --- 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; /* -- 1.8.3.1
