The patch titled Subject: memcg: fix destination cgroup leak on task charges migration has been removed from the -mm tree. Its filename was memcg-fix-destination-cgroup-leak-on-task-charges-migration.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Subject: memcg: fix destination cgroup leak on task charges migration We are supposed to take one css reference per each memory page and per each swap entry accounted to a memory cgroup. However, during task charges migration we take a reference to the destination cgroup twice per each swap entry: first in mem_cgroup_do_precharge()->try_charge() and then in mem_cgroup_move_swap_account(), permanently leaking the destination cgroup. The hunk taking the second reference seems to be a leftover from the pre-00501b531c472 ("mm: memcontrol: rewrite charge API") era. Remove it to fix the leak. Fixes: e8ea14cc6ead (mm: memcontrol: take a css reference for each charged page) Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 12 ------------ 1 file changed, 12 deletions(-) diff -puN mm/memcontrol.c~memcg-fix-destination-cgroup-leak-on-task-charges-migration mm/memcontrol.c --- a/mm/memcontrol.c~memcg-fix-destination-cgroup-leak-on-task-charges-migration +++ a/mm/memcontrol.c @@ -3043,18 +3043,6 @@ static int mem_cgroup_move_swap_account( if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { mem_cgroup_swap_statistics(from, false); mem_cgroup_swap_statistics(to, true); - /* - * This function is only called from task migration context now. - * It postpones page_counter and refcount handling till the end - * of task migration(mem_cgroup_clear_mc()) for performance - * improvement. But we cannot postpone css_get(to) because if - * the process that has been moved to @to does swap-in, the - * refcount of @to might be decreased to 0. - * - * We are in attach() phase, so the cgroup is guaranteed to be - * alive, so we can just call css_get(). - */ - css_get(&to->css); return 0; } return -EINVAL; _ Patches currently in -mm which might be from vdavydov@xxxxxxxxxxxxx are memcg-zap-__memcg_chargeuncharge_slab.patch memcg-zap-memcg_name-argument-of-memcg_create_kmem_cache.patch memcg-zap-memcg_slab_caches-and-memcg_slab_mutex.patch swap-remove-unused-mem_cgroup_uncharge_swapcache-declaration.patch mm-memcontrol-track-move_lock-state-internally.patch mm-vmscan-wake-up-all-pfmemalloc-throttled-processes-at-once.patch list_lru-introduce-list_lru_shrink_countwalk.patch fs-consolidate-nrfree_cached_objects-args-in-shrink_control.patch vmscan-per-memory-cgroup-slab-shrinkers.patch memcg-rename-some-cache-id-related-variables.patch memcg-add-rwsem-to-synchronize-against-memcg_caches-arrays-relocation.patch list_lru-get-rid-of-active_nodes.patch list_lru-organize-all-list_lrus-to-list.patch list_lru-introduce-per-memcg-lists.patch fs-make-shrinker-memcg-aware.patch vmscan-force-scan-offline-memory-cgroups.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html