[Pmem] [PATCH 2/4] mm/migrate: correct thp migration stats

From: Zi Yan <ziy(a)nvidia.com> ANBZ: #80 commit 6c5c7b9f3352728af490183f71d350bb658ffb75 upstream 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: 1a5bae25e3cf ("mm/vmstat: add events for THP migration without split") Signed-off-by: Zi Yan <ziy(a)nvidia.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan(a)oracle.com> Cc: Anshuman Khandual <anshuman.khandual(a)arm.com> Link: https://lkml.kernel.org/r/20200917210413.1462975-1-zi.yan@sent.com Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Baolin Wang <baolin.wang(a)linux.alibaba.com> --- mm/migrate.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 9cbf2ec..1ce6cf4 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1489,7 +1489,7 @@ 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 = hpage_nr_pages(page); cond_resched(); @@ -1515,7 +1515,7 @@ 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); @@ -1524,8 +1524,7 @@ 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; -- 1.8.3.1