| Message ID | 20220711084948.274787-4-ying.huang@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [-V2,1/7] migrate: fix syscall move_pages() return value for failure | expand |
On Mon, Jul 11, 2022 at 04:49:44PM +0800, Huang Ying wrote: > In unmap_and_move(), if the new THP cannot be allocated, -ENOMEM will > be returned, and migrate_pages() will try to split the THP unless > "reason" is MR_NUMA_MISPLACED (that is, nosplit == true). But when > nosplit == true, the THP migration failure will not be counted. This > is incorrect. So in this patch, the THP migration failure will be > counted for -ENOMEM regardless of nosplit is true or false. The > nr_failed counting isn't fixed because it's not used. Added some > comments for it per Baolin's suggestion. > > Signed-off-by: "Huang, Ying" <ying.huang@intel.com> > Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") > Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> > Cc: Zi Yan <ziy@nvidia.com> > Cc: Yang Shi <shy828301@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> > --- > mm/migrate.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 794312072eb3..38e2c789a9c3 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1426,11 +1426,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > /* > * When memory is low, don't bother to try to migrate > * other pages, just exit. > - * THP NUMA faulting doesn't split THP to retry. > */ > - if (is_thp && !nosplit) { > + if (is_thp) { > nr_thp_failed++; > - if (!try_split_thp(page, &thp_split_pages)) { > + /* THP NUMA faulting doesn't split THP to retry. */ > + if (!nosplit && !try_split_thp(page, &thp_split_pages)) { > nr_thp_split++; > goto retry; > } > @@ -1446,6 +1446,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > * the caller otherwise the page refcnt will be leaked. > */ > list_splice_init(&thp_split_pages, from); > + /* nr_failed isn't updated for not used */ > nr_thp_failed += thp_retry; > goto out; > case -EAGAIN: > -- > 2.30.2 > >
diff --git a/mm/migrate.c b/mm/migrate.c index 794312072eb3..38e2c789a9c3 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1426,11 +1426,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, /* * When memory is low, don't bother to try to migrate * other pages, just exit. - * THP NUMA faulting doesn't split THP to retry. */ - if (is_thp && !nosplit) { + if (is_thp) { nr_thp_failed++; - if (!try_split_thp(page, &thp_split_pages)) { + /* THP NUMA faulting doesn't split THP to retry. */ + if (!nosplit && !try_split_thp(page, &thp_split_pages)) { nr_thp_split++; goto retry; } @@ -1446,6 +1446,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, * the caller otherwise the page refcnt will be leaked. */ list_splice_init(&thp_split_pages, from); + /* nr_failed isn't updated for not used */ nr_thp_failed += thp_retry; goto out; case -EAGAIN: