From: Roman Gushchin <guro@fb.com> mainline inclusion from mainline-5.3-rc1 commit 49a18eae2e98a794477b5af5d85938e430c0be72 category: bugfix bugzilla: 34611 CVE: NA ------------------------------------------------- Let's separate the page counter modification code out of __memcg_kmem_uncharge() in a way similar to what __memcg_kmem_charge() and __memcg_kmem_charge_memcg() work. This will allow to reuse this code later using a new memcg_kmem_uncharge_memcg() wrapper, which calls __memcg_kmem_uncharge_memcg() if memcg_kmem_enabled() check is passed. Link: http://lkml.kernel.org/r/20190611231813.3148843-5-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 49a18eae2e98a794477b5af5d85938e430c0be72) Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- include/linux/memcontrol.h | 10 ++++++++++ mm/memcontrol.c | 25 +++++++++++++++++-------- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 24068566ada2..eafc13eb9441 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1275,6 +1275,8 @@ int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order); void __memcg_kmem_uncharge(struct page *page, int order); int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, struct mem_cgroup *memcg); +void __memcg_kmem_uncharge_memcg(struct mem_cgroup *memcg, + unsigned int nr_pages); extern struct static_key_false memcg_kmem_enabled_key; extern struct workqueue_struct *memcg_kmem_cache_wq; @@ -1316,6 +1318,14 @@ static inline int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, return __memcg_kmem_charge_memcg(page, gfp, order, memcg); return 0; } + +static inline void memcg_kmem_uncharge_memcg(struct page *page, int order, + struct mem_cgroup *memcg) +{ + if (memcg_kmem_enabled()) + __memcg_kmem_uncharge_memcg(memcg, 1 << order); +} + /* * helper for accessing a memcg's index. It will be used as an index in the * child cache array in kmem_cache, and also to derive its name. This function diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 66f87c8cfd7f..4f07c6db5c68 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2716,6 +2716,22 @@ int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order) css_put(&memcg->css); return ret; } + +/** + * __memcg_kmem_uncharge_memcg: uncharge a kmem page + * @memcg: memcg to uncharge + * @nr_pages: number of pages to uncharge + */ +void __memcg_kmem_uncharge_memcg(struct mem_cgroup *memcg, + unsigned int nr_pages) +{ + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + page_counter_uncharge(&memcg->kmem, nr_pages); + + page_counter_uncharge(&memcg->memory, nr_pages); + if (do_memsw_account()) + page_counter_uncharge(&memcg->memsw, nr_pages); +} /** * __memcg_kmem_uncharge: uncharge a kmem page * @page: page to uncharge @@ -2730,14 +2746,7 @@ void __memcg_kmem_uncharge(struct page *page, int order) return; VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page); - - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) - page_counter_uncharge(&memcg->kmem, nr_pages); - - page_counter_uncharge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, nr_pages); - + __memcg_kmem_uncharge_memcg(memcg, nr_pages); page->mem_cgroup = NULL; /* slab pages do not have PageKmemcg flag set */ -- 2.25.1