diff options
| author | Roman Gushchin <roman.gushchin@linux.dev> | 2023-02-13 11:29:22 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-16 20:43:56 -0800 |
| commit | f7a449f779608efe1941a0e0c4bd7b5f57000be7 (patch) | |
| tree | f8f97a44778de08a806b9e06a4c54e331273a043 /mm/memcontrol.c | |
| parent | b4fb12e6c74791ac4c5c98b845628c576366b889 (diff) | |
mm: memcontrol: rename memcg_kmem_enabled()
Currently there are two kmem-related helper functions with a confusing
semantics: memcg_kmem_enabled() and mem_cgroup_kmem_disabled().
The problem is that an obvious expectation
memcg_kmem_enabled() == !mem_cgroup_kmem_disabled(),
can be false.
mem_cgroup_kmem_disabled() is similar to mem_cgroup_disabled(): it returns
true only if CONFIG_MEMCG_KMEM is not set or the kmem accounting is
disabled using a boot time kernel option "cgroup.memory=nokmem". It never
changes the value dynamically.
memcg_kmem_enabled() is different: it always returns false until the first
non-root memory cgroup will get online (assuming the kernel memory
accounting is enabled). It's goal is to improve the performance on
systems without the cgroupfs mounted/memory controller enabled or on the
systems with only the root memory cgroup.
To make things more obvious and avoid potential bugs, let's rename
memcg_kmem_enabled() to memcg_kmem_online().
Link: https://lkml.kernel.org/r/20230213192922.1146370-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 17335459d8dc..3e3cdb9bed95 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -345,8 +345,8 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg, * conditional to this static branch, we'll have to allow modules that does * kmem_cache_alloc and the such to see this symbol as well */ -DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); -EXPORT_SYMBOL(memcg_kmem_enabled_key); +DEFINE_STATIC_KEY_FALSE(memcg_kmem_online_key); +EXPORT_SYMBOL(memcg_kmem_online_key); #endif /** @@ -3034,7 +3034,7 @@ struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) { struct obj_cgroup *objcg; - if (!memcg_kmem_enabled()) + if (!memcg_kmem_online()) return NULL; if (PageMemcgKmem(page)) { @@ -3746,7 +3746,7 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) objcg->memcg = memcg; rcu_assign_pointer(memcg->objcg, objcg); - static_branch_enable(&memcg_kmem_enabled_key); + static_branch_enable(&memcg_kmem_online_key); memcg->kmemcg_id = memcg->id.id; |