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| author |   Baolin Wang <baolin.wang@linux.alibaba.com> | 2022-10-24 16:34:21 +0800 |
|---|---|---|
| committer |   Andrew Morton <akpm@linux-foundation.org> | 2022-10-28 13:37:22 -0700 |
| commit | 03e5f82ea632af329e32ec03d952b2d99497eeaa (patch) | |
| tree | 962e0a0e67331bb2109565ee8ed5b35a77234cf9 /mm/migrate.c | |
| parent | mm/uffd: fix vma check on userfault for wp (diff) | |
| download | linux-dev-03e5f82ea632af329e32ec03d952b2d99497eeaa.tar.xz linux-dev-03e5f82ea632af329e32ec03d952b2d99497eeaa.zip | |
mm: migrate: fix return value if all subpages of THPs are migrated successfully
During THP migration, if THPs are not migrated but they are split and all
subpages are migrated successfully, migrate_pages() will still return the
number of THP pages that were not migrated. This will confuse the callers
of migrate_pages(). For example, the longterm pinning will failed though
all pages are migrated successfully.
Thus we should return 0 to indicate that all pages are migrated in this
case
Link: https://lkml.kernel.org/r/de386aa864be9158d2f3b344091419ea7c38b2f7.1666599848.git.baolin.wang@linux.alibaba.com
Fixes: b5bade978e9b ("mm: migrate: fix the return value of migrate_pages()")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 1379e1912772..dff333593a8a 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1582,6 +1582,13 @@ out: */ list_splice(&ret_pages, from); + /* + * Return 0 in case all subpages of fail-to-migrate THPs are + * migrated successfully. + */ + if (list_empty(from)) + rc = 0; + count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); count_vm_events(PGMIGRATE_FAIL, nr_failed_pages); count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded); |