From 900a38f027b37b55ebe157a0cb31de351b91e4e2 Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Fri, 12 Dec 2014 16:55:10 -0800 Subject: [PATCH] memcg: zap kmem_account_flags The only such flag is KMEM_ACCOUNTED_ACTIVE, but it's set iff mem_cgroup->kmemcg_id is initialized, so we can check kmemcg_id instead of having a separate flags field. Signed-off-by: Vladimir Davydov Cc: Johannes Weiner Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 31 ++++++++++--------------------- 1 file changed, 10 insertions(+), 21 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5a27e224d561..bb8c237026cc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -296,7 +296,6 @@ struct mem_cgroup { * Should the accounting and control be hierarchical, per subtree? */ bool use_hierarchy; - unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */ bool oom_lock; atomic_t under_oom; @@ -366,22 +365,11 @@ struct mem_cgroup { /* WARNING: nodeinfo must be the last member here */ }; -/* internal only representation about the status of kmem accounting. */ -enum { - KMEM_ACCOUNTED_ACTIVE, /* accounted by this cgroup itself */ -}; - #ifdef CONFIG_MEMCG_KMEM -static inline void memcg_kmem_set_active(struct mem_cgroup *memcg) -{ - set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); -} - static bool memcg_kmem_is_active(struct mem_cgroup *memcg) { - return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags); + return memcg->kmemcg_id >= 0; } - #endif /* Stuffs for move charges at task migration. */ @@ -3564,23 +3552,21 @@ static int memcg_activate_kmem(struct mem_cgroup *memcg, goto out; } - memcg->kmemcg_id = memcg_id; - INIT_LIST_HEAD(&memcg->memcg_slab_caches); - /* - * We couldn't have accounted to this cgroup, because it hasn't got the - * active bit set yet, so this should succeed. + * We couldn't have accounted to this cgroup, because it hasn't got + * activated yet, so this should succeed. */ err = page_counter_limit(&memcg->kmem, nr_pages); VM_BUG_ON(err); static_key_slow_inc(&memcg_kmem_enabled_key); /* - * Setting the active bit after enabling static branching will + * A memory cgroup is considered kmem-active as soon as it gets + * kmemcg_id. Setting the id after enabling static branching will * guarantee no one starts accounting before all call sites are * patched. */ - memcg_kmem_set_active(memcg); + memcg->kmemcg_id = memcg_id; out: return err; } @@ -4252,7 +4238,6 @@ static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss) { int ret; - memcg->kmemcg_id = -1; ret = memcg_propagate_kmem(memcg); if (ret) return ret; @@ -4786,6 +4771,10 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) vmpressure_init(&memcg->vmpressure); INIT_LIST_HEAD(&memcg->event_list); spin_lock_init(&memcg->event_list_lock); +#ifdef CONFIG_MEMCG_KMEM + memcg->kmemcg_id = -1; + INIT_LIST_HEAD(&memcg->memcg_slab_caches); +#endif return &memcg->css; -- 2.20.1