The patch titled Subject: mm, slab: memcg_link the SLAB's kmem_cache has been added to the -mm tree. Its filename is mm-slab-memcg_link-the-slabs-kmem_cache.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-slab-memcg_link-the-slabs-kmem_cache.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-slab-memcg_link-the-slabs-kmem_cache.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: Shakeel Butt <shakeelb@xxxxxxxxxx> Subject: mm, slab: memcg_link the SLAB's kmem_cache All the root caches are linked into slab_root_caches which was introduced by the commit 510ded33e075 ("slab: implement slab_root_caches list") but it missed to add the SLAB's kmem_cache. While experimenting with opt-in/opt-out kmem accounting, I noticed system crashes due to NULL dereference inside cache_from_memcg_idx() while deferencing kmem_cache.memcg_params.memcg_caches. The upstream clean kernel will not see these crashes but SLAB should be consistent with SLUB which does linked its boot caches (kmem_cache_node and kmem_cache) into slab_root_caches. Link: http://lkml.kernel.org/r/20180319210020.60289-1-shakeelb@xxxxxxxxxx Fixes: 510ded33e075c ("slab: implement slab_root_caches list") Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Greg Thelen <gthelen@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab.c | 1 + 1 file changed, 1 insertion(+) diff -puN mm/slab.c~mm-slab-memcg_link-the-slabs-kmem_cache mm/slab.c --- a/mm/slab.c~mm-slab-memcg_link-the-slabs-kmem_cache +++ a/mm/slab.c @@ -1283,6 +1283,7 @@ void __init kmem_cache_init(void) nr_node_ids * sizeof(struct kmem_cache_node *), SLAB_HWCACHE_ALIGN, 0, 0); list_add(&kmem_cache->list, &slab_caches); + memcg_link_cache(kmem_cache); slab_state = PARTIAL; /* _ Patches currently in -mm which might be from shakeelb@xxxxxxxxxx are mm-slab-memcg_link-the-slabs-kmem_cache.patch slab-slub-remove-size-disparity-on-debug-kernel.patch mm-memcg-remote-memcg-charging-for-kmem-allocations.patch fs-fsnotify-account-fsnotify-metadata-to-kmemcg.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