Re: [PATCH v3] memcg: remove unnecessary thp check at page stat accounting
From: Michal Hocko <hidden>
Date: 2012-01-20 08:43:13
Also in:
lkml
On Fri 20-01-12 12:25:12, KAMEZAWA Hiroyuki wrote:
Updated description. == From a6395205d9f517af7963ff61d66efbcf1c64b2a5 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki <redacted> Date: Thu, 12 Jan 2012 16:08:33 +0900 Subject: [PATCH v3] memcg: remove unnecessary check in mem_cgroup_update_page_stat() This patch is a fix for
I would rather call it a follow up for this patch. It doesn't fixes it.
memcg: make mem_cgroup_split_huge_fixup() more efficient Above patch removes move_lock_page_cgroup(). So, we do not have to check PageTransHuge in mem_cgroup_update_page_stat and fallback into the locked accounting because both move_account and thp split are done with compound_lock so they cannot race. The race between update vs. move is protected by mem_cgroup_stealed, PageTransHuge pages shouldn't appear in this code path currently because we are tracking only file pages at the moment but later we are planning to track also other pages (e.g. mlocked ones). Changelog: - updated description. Signed-off-by: KAMEZAWA Hiroyuki <redacted>
Anyway Acked-by: Michal Hocko <redacted> Thanks
quoted hunk ↗ jump to hunk
--- mm/memcontrol.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3dbff4d..ff24520 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c@@ -1867,7 +1867,7 @@ void mem_cgroup_update_page_stat(struct page *page, if (unlikely(!memcg || !PageCgroupUsed(pc))) goto out; /* pc->mem_cgroup is unstable ? */ - if (unlikely(mem_cgroup_stealed(memcg)) || PageTransHuge(page)) { + if (unlikely(mem_cgroup_stealed(memcg))) { /* take a lock against to access pc->mem_cgroup */ move_lock_page_cgroup(pc, &flags); need_unlock = true;-- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>