The patch titled
Subject: mm/migrate: correct thp migration stats.
has been added to the -mm tree. Its filename is
mm-migrate-correct-thp-migration-stats.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-migrate-correct-thp-migration-stats.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-migrate-correct-thp-migration-stats.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Zi Yan <ziy@xxxxxxxxxx>
Subject: mm/migrate: correct thp migration stats.
PageTransHuge returns true for both thp and hugetlb, so thp stats was
counting both thp and hugetlb migrations. Exclude hugetlb migration by
setting is_thp variable right.
Clean up thp handling code too when we are there.
Link: https://lkml.kernel.org/r/20200917210413.1462975-1-zi.yan@xxxxxxxx
Fixes: 1a5bae25e3cf ("mm/vmstat: add events for THP migration without split")
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
--- a/mm/migrate.c~mm-migrate-correct-thp-migration-stats
+++ a/mm/migrate.c
@@ -1446,7 +1446,7 @@ retry:
* Capture required information that might get lost
* during migration.
*/
- is_thp = PageTransHuge(page);
+ is_thp = PageTransHuge(page) && !PageHuge(page);
nr_subpages = thp_nr_pages(page);
cond_resched();
@@ -1472,7 +1472,7 @@ retry:
* we encounter them after the rest of the list
* is processed.
*/
- if (PageTransHuge(page) && !PageHuge(page)) {
+ if (is_thp) {
lock_page(page);
rc = split_huge_page_to_list(page, from);
unlock_page(page);
@@ -1481,8 +1481,7 @@ retry:
nr_thp_split++;
goto retry;
}
- }
- if (is_thp) {
+
nr_thp_failed++;
nr_failed += nr_subpages;
goto out;
_
Patches currently in -mm which might be from ziy@xxxxxxxxxx are
mm-migrate-correct-thp-migration-stats.patch
