[merged mm-stable] mm-migrate-do-not-retry-10-times-for-the-subpages-of-fail-to-migrate-thp.patch removed from -mm tree

[merged mm-stable] mm-migrate-do-not-retry-10-times-for-the-subpages-of-fail-to-migrate-thp.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: migrate: do not retry 10 times for the subpages of fail-to-migrate THP
has been removed from the -mm tree.  Its filename was
     mm-migrate-do-not-retry-10-times-for-the-subpages-of-fail-to-migrate-thp.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Subject: mm: migrate: do not retry 10 times for the subpages of fail-to-migrate THP
Date: Wed, 17 Aug 2022 16:14:08 +0800

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(-)

--- a/mm/migrate.c~mm-migrate-do-not-retry-10-times-for-the-subpages-of-fail-to-migrate-thp
+++ a/mm/migrate.c
@@ -1522,7 +1522,7 @@ thp_subpage_migration:
 			case -EAGAIN:
 				if (is_thp)
 					thp_retry++;
-				else
+				else if (!no_subpage_counting)
 					retry++;
 				nr_retry_pages += nr_subpages;
 				break;
@@ -1548,8 +1548,7 @@ thp_subpage_migration:
 			}
 		}
 	}
-	if (!no_subpage_counting)
-		nr_failed += retry;
+	nr_failed += retry;
 	nr_thp_failed += thp_retry;
 	nr_failed_pages += nr_retry_pages;
 	/*
_

Patches currently in -mm which might be from baolin.wang@linux.alibaba.com are

mm-hugetlb-fix-races-when-looking-up-a-cont-pte-pmd-size-hugetlb-page.patch