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authorHuang Ying <ying.huang@intel.com>2022-08-17 10:14:03 +0200
committerAndrew Morton <akpm@linux-foundation.org>2022-09-27 04:46:06 +0200
commitfbed53b47770b978be290cec0f4f22577766c12d (patch)
tree8fc63101ae1ec85cc074b873d3f424148351d520 /mm/migrate.c
parentmigrate_pages(): remove unnecessary list_safe_reset_next() (diff)
downloadlinux-fbed53b47770b978be290cec0f4f22577766c12d.tar.xz
linux-fbed53b47770b978be290cec0f4f22577766c12d.zip
migrate_pages(): fix THP failure counting for -ENOMEM
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. Link: https://lkml.kernel.org/r/20220817081408.513338-4-ying.huang@intel.com Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: 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>
Diffstat (limited to 'mm/migrate.c')
-rw-r--r--mm/migrate.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 19a9b26af7e2..ae55f08e72ce 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1494,11 +1494,11 @@ retry:
/*
* 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;
}
@@ -1514,6 +1514,7 @@ retry:
* 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: