The patch titled Subject: mm: memcg/slab: don't check the dying flag on kmem_cache creation has been added to the -mm tree. Its filename is mm-dont-check-the-dying-flag-on-kmem_cache-creation.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-dont-check-the-dying-flag-on-kmem_cache-creation.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-dont-check-the-dying-flag-on-kmem_cache-creation.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Roman Gushchin <guro@xxxxxx> Subject: mm: memcg/slab: don't check the dying flag on kmem_cache creation There is no point in checking the root_cache->memcg_params.dying flag on kmem_cache creation path. New allocations shouldn't be performed using a dead root kmem_cache, so no new memcg kmem_cache creation can be scheduled after the flag is set. And if it was scheduled before, flush_memcg_workqueue() will wait for it anyway. So let's drop this check to simplify the code. Link: http://lkml.kernel.org/r/20190611231813.3148843-7-guro@xxxxxx Signed-off-by: Roman Gushchin <guro@xxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Waiman Long <longman@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/slab_common.c~mm-dont-check-the-dying-flag-on-kmem_cache-creation +++ a/mm/slab_common.c @@ -640,7 +640,7 @@ void memcg_create_kmem_cache(struct mem_ * The memory cgroup could have been offlined while the cache * creation work was pending. */ - if (memcg->kmem_state != KMEM_ONLINE || root_cache->memcg_params.dying) + if (memcg->kmem_state != KMEM_ONLINE) goto out_unlock; idx = memcg_cache_id(memcg); _ Patches currently in -mm which might be from guro@xxxxxx are mm-postpone-kmem_cache-memcg-pointer-initialization-to-memcg_link_cache.patch mm-rename-slab-delayed-deactivation-functions-and-fields.patch mm-generalize-postponed-non-root-kmem_cache-deactivation.patch mm-introduce-__memcg_kmem_uncharge_memcg.patch mm-unify-slab-and-slub-page-accounting.patch mm-dont-check-the-dying-flag-on-kmem_cache-creation.patch mm-synchronize-access-to-kmem_cache-dying-flag-using-a-spinlock.patch mm-rework-non-root-kmem_cache-lifecycle-management.patch mm-stop-setting-page-mem_cgroup-pointer-for-slab-pages.patch mm-reparent-memcg-kmem_caches-on-cgroup-removal.patch