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.

Fixes: 1a5bae25e3 ("mm/vmstat: add events for THP migration without split")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lkml.kernel.org/r/20200917210413.1462975-1-zi.yan@sent.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Zi Yan 2020-09-25 21:19:14 -07:00 committed by Linus Torvalds
parent d3f7b1bb20
commit 6c5c7b9f33

View file

@ -1446,7 +1446,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
* 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 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
* 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 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
nr_thp_split++;
goto retry;
}
}
if (is_thp) {
nr_thp_failed++;
nr_failed += nr_subpages;
goto out;