From: Greg Kroah-Hartman Date: Mon, 30 Mar 2020 13:21:02 +0000 (+0200) Subject: 5.4-stable patches X-Git-Tag: v5.6.1~47 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4b8b528aea385f6e0f0b4c6d503c1e008d3f0f1a;p=thirdparty%2Fkernel%2Fstable-queue.git 5.4-stable patches added patches: mm-fork-fix-kernel_stack-memcg-stats-for-various-stack-implementations.patch --- diff --git a/queue-5.4/mm-fork-fix-kernel_stack-memcg-stats-for-various-stack-implementations.patch b/queue-5.4/mm-fork-fix-kernel_stack-memcg-stats-for-various-stack-implementations.patch new file mode 100644 index 00000000000..72deee093a4 --- /dev/null +++ b/queue-5.4/mm-fork-fix-kernel_stack-memcg-stats-for-various-stack-implementations.patch @@ -0,0 +1,166 @@ +From 8380ce479010f2f779587b462a9b4681934297c3 Mon Sep 17 00:00:00 2001 +From: Roman Gushchin +Date: Sat, 28 Mar 2020 19:17:25 -0700 +Subject: mm: fork: fix kernel_stack memcg stats for various stack implementations + +From: Roman Gushchin + +commit 8380ce479010f2f779587b462a9b4681934297c3 upstream. + +Depending on CONFIG_VMAP_STACK and the THREAD_SIZE / PAGE_SIZE ratio the +space for task stacks can be allocated using __vmalloc_node_range(), +alloc_pages_node() and kmem_cache_alloc_node(). + +In the first and the second cases page->mem_cgroup pointer is set, but +in the third it's not: memcg membership of a slab page should be +determined using the memcg_from_slab_page() function, which looks at +page->slab_cache->memcg_params.memcg . In this case, using +mod_memcg_page_state() (as in account_kernel_stack()) is incorrect: +page->mem_cgroup pointer is NULL even for pages charged to a non-root +memory cgroup. + +It can lead to kernel_stack per-memcg counters permanently showing 0 on +some architectures (depending on the configuration). + +In order to fix it, let's introduce a mod_memcg_obj_state() helper, +which takes a pointer to a kernel object as a first argument, uses +mem_cgroup_from_obj() to get a RCU-protected memcg pointer and calls +mod_memcg_state(). It allows to handle all possible configurations +(CONFIG_VMAP_STACK and various THREAD_SIZE/PAGE_SIZE values) without +spilling any memcg/kmem specifics into fork.c . + +Note: This is a special version of the patch created for stable +backports. It contains code from the following two patches: + - mm: memcg/slab: introduce mem_cgroup_from_obj() + - mm: fork: fix kernel_stack memcg stats for various stack implementations + +[guro@fb.com: introduce mem_cgroup_from_obj()] + Link: http://lkml.kernel.org/r/20200324004221.GA36662@carbon.dhcp.thefacebook.com +Fixes: 4d96ba353075 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages") +Signed-off-by: Roman Gushchin +Signed-off-by: Andrew Morton +Reviewed-by: Shakeel Butt +Acked-by: Johannes Weiner +Cc: Michal Hocko +Cc: Bharata B Rao +Cc: Shakeel Butt +Cc: +Link: http://lkml.kernel.org/r/20200303233550.251375-1-guro@fb.com +Signed-off-by: Linus Torvalds +Signed-off-by: Greg Kroah-Hartman + +--- + include/linux/memcontrol.h | 12 ++++++++++++ + kernel/fork.c | 4 ++-- + mm/memcontrol.c | 38 ++++++++++++++++++++++++++++++++++++++ + 3 files changed, 52 insertions(+), 2 deletions(-) + +--- a/include/linux/memcontrol.h ++++ b/include/linux/memcontrol.h +@@ -705,6 +705,7 @@ static inline unsigned long lruvec_page_ + void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, + int val); + void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val); ++void mod_memcg_obj_state(void *p, int idx, int val); + + static inline void mod_lruvec_state(struct lruvec *lruvec, + enum node_stat_item idx, int val) +@@ -1128,6 +1129,10 @@ static inline void __mod_lruvec_slab_sta + __mod_node_page_state(page_pgdat(page), idx, val); + } + ++static inline void mod_memcg_obj_state(void *p, int idx, int val) ++{ ++} ++ + static inline + unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, + gfp_t gfp_mask, +@@ -1432,6 +1437,8 @@ static inline int memcg_cache_id(struct + return memcg ? memcg->kmemcg_id : -1; + } + ++struct mem_cgroup *mem_cgroup_from_obj(void *p); ++ + #else + + static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order) +@@ -1473,6 +1480,11 @@ static inline void memcg_put_cache_ids(v + { + } + ++static inline struct mem_cgroup *mem_cgroup_from_obj(void *p) ++{ ++ return NULL; ++} ++ + #endif /* CONFIG_MEMCG_KMEM */ + + #endif /* _LINUX_MEMCONTROL_H */ +--- a/kernel/fork.c ++++ b/kernel/fork.c +@@ -394,8 +394,8 @@ static void account_kernel_stack(struct + mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB, + THREAD_SIZE / 1024 * account); + +- mod_memcg_page_state(first_page, MEMCG_KERNEL_STACK_KB, +- account * (THREAD_SIZE / 1024)); ++ mod_memcg_obj_state(stack, MEMCG_KERNEL_STACK_KB, ++ account * (THREAD_SIZE / 1024)); + } + } + +--- a/mm/memcontrol.c ++++ b/mm/memcontrol.c +@@ -786,6 +786,17 @@ void __mod_lruvec_slab_state(void *p, en + rcu_read_unlock(); + } + ++void mod_memcg_obj_state(void *p, int idx, int val) ++{ ++ struct mem_cgroup *memcg; ++ ++ rcu_read_lock(); ++ memcg = mem_cgroup_from_obj(p); ++ if (memcg) ++ mod_memcg_state(memcg, idx, val); ++ rcu_read_unlock(); ++} ++ + /** + * __count_memcg_events - account VM events in a cgroup + * @memcg: the memory cgroup +@@ -2778,6 +2789,33 @@ static void commit_charge(struct page *p + } + + #ifdef CONFIG_MEMCG_KMEM ++/* ++ * Returns a pointer to the memory cgroup to which the kernel object is charged. ++ * ++ * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), ++ * cgroup_mutex, etc. ++ */ ++struct mem_cgroup *mem_cgroup_from_obj(void *p) ++{ ++ struct page *page; ++ ++ if (mem_cgroup_disabled()) ++ return NULL; ++ ++ page = virt_to_head_page(p); ++ ++ /* ++ * Slab pages don't have page->mem_cgroup set because corresponding ++ * kmem caches can be reparented during the lifetime. That's why ++ * memcg_from_slab_page() should be used instead. ++ */ ++ if (PageSlab(page)) ++ return memcg_from_slab_page(page); ++ ++ /* All other pages use page->mem_cgroup */ ++ return page->mem_cgroup; ++} ++ + static int memcg_alloc_cache_id(void) + { + int id, size; diff --git a/queue-5.4/series b/queue-5.4/series index 5e412fe402f..5eea21cf8de 100644 --- a/queue-5.4/series +++ b/queue-5.4/series @@ -100,3 +100,4 @@ mac80211-mark-station-unauthorized-before-key-removal.patch mm-swapfile.c-move-inode_lock-out-of-claim_swapfile.patch drivers-base-memory.c-indicate-all-memory-blocks-as-removable.patch mm-sparse-fix-kernel-crash-with-pfn_section_valid-check.patch +mm-fork-fix-kernel_stack-memcg-stats-for-various-stack-implementations.patch