The patch titled Subject: memcg: increment static branch right after limit set has been removed from the -mm tree. Its filename was memcg-increment-static-branch-right-after-limit-set.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Glauber Costa <glommer@xxxxxxxxxxxxx> Subject: memcg: increment static branch right after limit set We were deferring the kmemcg static branch increment to a later time, due to a nasty dependency between the cpu_hotplug lock, taken by the jump label update, and the cgroup_lock. Now we no longer take the cgroup lock, and we can save ourselves the trouble. Signed-off-by: Glauber Costa <glommer@xxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 31 +++++++------------------------ 1 file changed, 7 insertions(+), 24 deletions(-) diff -puN mm/memcontrol.c~memcg-increment-static-branch-right-after-limit-set mm/memcontrol.c --- a/mm/memcontrol.c~memcg-increment-static-branch-right-after-limit-set +++ a/mm/memcontrol.c @@ -4974,8 +4974,6 @@ static int memcg_update_kmem_limit(struc { int ret = -EINVAL; #ifdef CONFIG_MEMCG_KMEM - bool must_inc_static_branch = false; - struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); /* * For simplicity, we won't allow this to be disabled. It also can't @@ -5004,7 +5002,13 @@ static int memcg_update_kmem_limit(struc res_counter_set_limit(&memcg->kmem, RESOURCE_MAX); goto out; } - must_inc_static_branch = true; + static_key_slow_inc(&memcg_kmem_enabled_key); + /* + * setting the active bit after the inc will guarantee no one + * starts accounting before all call sites are patched + */ + memcg_kmem_set_active(memcg); + /* * kmem charges can outlive the cgroup. In the case of slab * pages, for instance, a page contain objects from various @@ -5017,27 +5021,6 @@ static int memcg_update_kmem_limit(struc out: mutex_unlock(&set_limit_mutex); mutex_unlock(&memcg_create_mutex); - - /* - * We are by now familiar with the fact that we can't inc the static - * branch inside cgroup_lock. See disarm functions for details. A - * worker here is overkill, but also wrong: After the limit is set, we - * must start accounting right away. Since this operation can't fail, - * we can safely defer it to here - no rollback will be needed. - * - * The boolean used to control this is also safe, because - * KMEM_ACCOUNTED_ACTIVATED guarantees that only one process will be - * able to set it to true; - */ - if (must_inc_static_branch) { - static_key_slow_inc(&memcg_kmem_enabled_key); - /* - * setting the active bit after the inc will guarantee no one - * starts accounting before all call sites are patched - */ - memcg_kmem_set_active(memcg); - } - #endif return ret; } _ Patches currently in -mm which might be from glommer@xxxxxxxxxxxxx are origin.patch linux-next.patch slub-correctly-bootstrap-boot-caches.patch memcg-debugging-facility-to-access-dangling-memcgs.patch memcg-debugging-facility-to-access-dangling-memcgs-fix.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