From efdc94907977d2db84b4b00cb9bd98ca011f6819 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 28 Jul 2016 15:48:17 -0700 Subject: [PATCH] mm: fix memcg stack accounting for sub-page stacks We should account for stacks regardless of stack size, and we need to account in sub-page units if THREAD_SIZE < PAGE_SIZE. Change the units to kilobytes and Move it into account_kernel_stack(). Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat") Link: http://lkml.kernel.org/r/9b5314e3ee5eda61b0317ec1563768602c1ef438.1468523549.git.luto@kernel.org Signed-off-by: Andy Lutomirski Cc: Vladimir Davydov Acked-by: Johannes Weiner Cc: Michal Hocko Reviewed-by: Josh Poimboeuf Reviewed-by: Vladimir Davydov Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 2 +- kernel/fork.c | 19 ++++++++----------- mm/memcontrol.c | 2 +- 3 files changed, 10 insertions(+), 13 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 5147e650287a..5d8ca6e02e39 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -52,7 +52,7 @@ enum mem_cgroup_stat_index { MEM_CGROUP_STAT_SWAP, /* # of pages, swapped out */ MEM_CGROUP_STAT_NSTATS, /* default hierarchy stats */ - MEMCG_KERNEL_STACK = MEM_CGROUP_STAT_NSTATS, + MEMCG_KERNEL_STACK_KB = MEM_CGROUP_STAT_NSTATS, MEMCG_SLAB_RECLAIMABLE, MEMCG_SLAB_UNRECLAIMABLE, MEMCG_SOCK, diff --git a/kernel/fork.c b/kernel/fork.c index af3637e0ee52..52e725d4a866 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -165,20 +165,12 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, struct page *page = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER); - if (page) - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, - 1 << THREAD_SIZE_ORDER); - return page ? page_address(page) : NULL; } static inline void free_thread_stack(unsigned long *stack) { - struct page *page = virt_to_page(stack); - - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, - -(1 << THREAD_SIZE_ORDER)); - __free_pages(page, THREAD_SIZE_ORDER); + __free_pages(virt_to_page(stack), THREAD_SIZE_ORDER); } # else static struct kmem_cache *thread_stack_cache; @@ -223,10 +215,15 @@ static struct kmem_cache *mm_cachep; static void account_kernel_stack(unsigned long *stack, int account) { - struct zone *zone = page_zone(virt_to_page(stack)); + /* All stack pages are in the same zone and belong to the same memcg. */ + struct page *first_page = virt_to_page(stack); - mod_zone_page_state(zone, NR_KERNEL_STACK_KB, + mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB, THREAD_SIZE / 1024 * account); + + memcg_kmem_update_page_stat( + first_page, MEMCG_KERNEL_STACK_KB, + account * (THREAD_SIZE / 1024)); } void free_task(struct task_struct *tsk) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 13be30c3ea78..c265212bec8c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5171,7 +5171,7 @@ static int memory_stat_show(struct seq_file *m, void *v) seq_printf(m, "file %llu\n", (u64)stat[MEM_CGROUP_STAT_CACHE] * PAGE_SIZE); seq_printf(m, "kernel_stack %llu\n", - (u64)stat[MEMCG_KERNEL_STACK] * PAGE_SIZE); + (u64)stat[MEMCG_KERNEL_STACK_KB] * 1024); seq_printf(m, "slab %llu\n", (u64)(stat[MEMCG_SLAB_RECLAIMABLE] + stat[MEMCG_SLAB_UNRECLAIMABLE]) * PAGE_SIZE); -- 2.20.1