Re: [PATCH 2/3] mm: Charge active memcg when no mm is set
From: Michal Koutný <mkoutny@suse.com>
Date: 2021-06-25 14:47:43
Also in:
linux-block, linux-mm, lkml
On Thu, Jun 10, 2021 at 10:39:43AM -0700, Dan Schatzberg [off-list ref] wrote:
quoted hunk ↗ jump to hunk
@@ -926,8 +937,17 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) * counting is disabled on the root level in the * cgroup core. See CSS_NO_REF. */ - if (unlikely(!mm)) - return root_mem_cgroup; + if (unlikely(!mm)) { + memcg = active_memcg(); + if (unlikely(memcg)) { + /* remote memcg must hold a ref */ + css_get(&memcg->css); + return memcg; + } + mm = current->mm; + if (unlikely(!mm)) + return root_mem_cgroup; + }
With the change in __add_to_page_cache_locked() all page cache charges will supply null mm, so the first !mm unlikely hint may not be warranted anymore. Just an interesting point, generally, I'm adding Reviewed-by: Michal Koutný <mkoutny@suse.com>
Attachments
- signature.asc [application/pgp-signature] 833 bytes