From 7047b5a40bce74883a10549bd609643b8bc4a3fb Mon Sep 17 00:00:00 2001 From: Baolin Wang <baolin.wang@linux.alibaba.com> Date: Wed, 17 Aug 2022 16:14:08 +0800 Subject: [PATCH] mm: migrate: do not retry 10 times for the subpages of fail-to-migrate THP 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@yhuang6-desk2.ccr.corp.intel.com/ Link: https://lkml.kernel.org/r/20220817081408.513338-9-ying.huang@intel.com Tested-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Zi Yan <ziy@nvidia.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/migrate.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 55fbf96694313..06a6539778351 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1522,7 +1522,7 @@ 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; @@ -1548,8 +1548,7 @@ 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; /* -- GitLab