| Message ID | 20220919180634.45958-2-ryncsn@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: memcontrol: cleanup and optimize for two accounting params | expand |
On Tue, Sep 20, 2022 at 02:06:33AM +0800, Kairui Song wrote: > From: Kairui Song <kasong@tencent.com> > > There are currently two helpers for checking if cgroup kmem > accounting is enabled: > > - mem_cgroup_kmem_disabled > - memcg_kmem_enabled > > mem_cgroup_kmem_disabled is a simple helper that returns true > if cgroup.memory=nokmem is specified, otherwise returns false. > > memcg_kmem_enabled is a bit different, it returns true if > cgroup.memory=nokmem is not specified and there was at least one > non-root memory control enabled cgroup ever created. This help improve > performance when kmem accounting was not actually activated. And it's > optimized with static branch. > > The usage of mem_cgroup_kmem_disabled is for sub-systems that need to > preallocate data for kmem accounting since they could be initialized > before kmem accounting is activated. But count_objcg_event doesn't > need that, so using memcg_kmem_enabled is better here. > > Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Shakeel Butt <shakeelb@google.com>
On Tue, Sep 20, 2022 at 02:06:33AM +0800, Kairui Song wrote: > From: Kairui Song <kasong@tencent.com> > > There are currently two helpers for checking if cgroup kmem > accounting is enabled: > > - mem_cgroup_kmem_disabled > - memcg_kmem_enabled > > mem_cgroup_kmem_disabled is a simple helper that returns true > if cgroup.memory=nokmem is specified, otherwise returns false. > > memcg_kmem_enabled is a bit different, it returns true if > cgroup.memory=nokmem is not specified and there was at least one > non-root memory control enabled cgroup ever created. This help improve > performance when kmem accounting was not actually activated. And it's > optimized with static branch. > > The usage of mem_cgroup_kmem_disabled is for sub-systems that need to > preallocate data for kmem accounting since they could be initialized > before kmem accounting is activated. But count_objcg_event doesn't > need that, so using memcg_kmem_enabled is better here. > > Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Thanks, Kairui!
> On Sep 20, 2022, at 02:06, Kairui Song <ryncsn@gmail.com> wrote: > > From: Kairui Song <kasong@tencent.com> > > There are currently two helpers for checking if cgroup kmem > accounting is enabled: > > - mem_cgroup_kmem_disabled > - memcg_kmem_enabled > > mem_cgroup_kmem_disabled is a simple helper that returns true > if cgroup.memory=nokmem is specified, otherwise returns false. > > memcg_kmem_enabled is a bit different, it returns true if > cgroup.memory=nokmem is not specified and there was at least one > non-root memory control enabled cgroup ever created. This help improve > performance when kmem accounting was not actually activated. And it's > optimized with static branch. > > The usage of mem_cgroup_kmem_disabled is for sub-systems that need to > preallocate data for kmem accounting since they could be initialized > before kmem accounting is activated. But count_objcg_event doesn't > need that, so using memcg_kmem_enabled is better here. > > Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Thanks.
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6257867fbf95..e6d3d5870d6f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1779,7 +1779,7 @@ static inline void count_objcg_event(struct obj_cgroup *objcg, { struct mem_cgroup *memcg; - if (mem_cgroup_kmem_disabled()) + if (!memcg_kmem_enabled()) return; rcu_read_lock();