linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Muchun Song <songmuchun@bytedance.com>
To: guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org,
	akpm@linux-foundation.org, shakeelb@google.com,
	vdavydov.dev@gmail.com
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	duanxiongchun@bytedance.com,
	Muchun Song <songmuchun@bytedance.com>
Subject: [RFC PATCH 01/15] mm: memcontrol: fix page charging in page replacement
Date: Tue, 30 Mar 2021 18:15:17 +0800	[thread overview]
Message-ID: <20210330101531.82752-2-songmuchun@bytedance.com> (raw)
In-Reply-To: <20210330101531.82752-1-songmuchun@bytedance.com>

The pages aren't accounted at the root level, so do not charge the page
to the root memcg in page replacement. Although we do not display the
value (mem_cgroup_usage) so there shouldn't be any actual problem, but
there is a WARN_ON_ONCE in the page_counter_cancel(). Who knows if it
will trigger? So it is better to fix it.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/memcontrol.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 249bf6b4d94c..d0c4f6e91e17 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6936,9 +6936,11 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
 	/* Force-charge the new page. The old one will be freed soon */
 	nr_pages = thp_nr_pages(newpage);
 
-	page_counter_charge(&memcg->memory, nr_pages);
-	if (do_memsw_account())
-		page_counter_charge(&memcg->memsw, nr_pages);
+	if (!mem_cgroup_is_root(memcg)) {
+		page_counter_charge(&memcg->memory, nr_pages);
+		if (do_memsw_account())
+			page_counter_charge(&memcg->memsw, nr_pages);
+	}
 
 	css_get(&memcg->css);
 	commit_charge(newpage, memcg);
-- 
2.11.0


  reply	other threads:[~2021-03-30 10:21 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30 10:15 [RFC PATCH 00/15] Use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-03-30 10:15 ` Muchun Song [this message]
2021-04-02 15:07   ` [RFC PATCH 01/15] mm: memcontrol: fix page charging in page replacement Johannes Weiner
2021-03-30 10:15 ` [RFC PATCH 02/15] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm Muchun Song
2021-04-02 15:08   ` Johannes Weiner
2021-03-30 10:15 ` [RFC PATCH 03/15] mm: memcontrol: remove the pgdata parameter of mem_cgroup_page_lruvec Muchun Song
2021-04-02 15:22   ` Johannes Weiner
2021-03-30 10:15 ` [RFC PATCH 04/15] mm: memcontrol: use lruvec_memcg in lruvec_holds_page_lru_lock Muchun Song
2021-04-02 16:21   ` Johannes Weiner
2021-04-03 12:37     ` [External] " Muchun Song
2021-03-30 10:15 ` [RFC PATCH 05/15] mm: memcontrol: simplify the logic of objcg pinning memcg Muchun Song
2021-03-30 10:15 ` [RFC PATCH 06/15] mm: memcontrol: move the objcg infrastructure out of CONFIG_MEMCG_KMEM Muchun Song
2021-03-30 10:15 ` [RFC PATCH 07/15] mm: memcontrol: introduce compact_lock_page_lruvec_irqsave Muchun Song
2021-03-30 10:15 ` [RFC PATCH 08/15] mm: memcontrol: make lruvec lock safe when the LRU pages reparented Muchun Song
2021-03-30 10:15 ` [RFC PATCH 09/15] mm: thp: introduce lock/unlock_split_queue{_irqsave}() Muchun Song
2021-03-30 10:15 ` [RFC PATCH 10/15] mm: thp: make deferred split queue lock safe when the LRU pages reparented Muchun Song
2021-03-30 10:15 ` [RFC PATCH 11/15] mm: memcontrol: make all the callers of page_memcg() safe Muchun Song
2021-03-30 10:15 ` [RFC PATCH 12/15] mm: memcontrol: introduce memcg_reparent_ops Muchun Song
2021-03-30 10:15 ` [RFC PATCH 13/15] mm: memcontrol: use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-03-30 10:15 ` [RFC PATCH 14/15] mm: memcontrol: rename {un}lock_page_memcg() to {un}lock_page_objcg() Muchun Song
2021-03-30 10:15 ` [RFC PATCH 15/15] mm: lru: add VM_BUG_ON_PAGE to lru maintenance function Muchun Song
2021-03-30 18:34 ` [RFC PATCH 00/15] Use obj_cgroup APIs to charge the LRU pages Shakeel Butt
2021-03-30 18:58   ` Roman Gushchin
2021-03-30 21:30     ` Johannes Weiner
2021-03-30 22:05       ` Roman Gushchin
2021-03-31 15:17         ` Johannes Weiner
2021-04-01 16:07           ` [External] " Muchun Song
2021-04-01 17:15             ` Shakeel Butt
2021-04-02  3:14               ` Muchun Song
2021-04-02 17:30               ` Johannes Weiner
2021-04-01 21:34             ` Roman Gushchin
2021-04-01 22:55           ` Yang Shi
2021-04-02  4:03             ` [External] " Muchun Song
2021-03-30 21:10   ` Johannes Weiner
2021-03-31  0:28     ` Shakeel Butt
2021-03-31  3:28     ` Balbir Singh

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210330101531.82752-2-songmuchun@bytedance.com \
    --to=songmuchun@bytedance.com \
    --cc=akpm@linux-foundation.org \
    --cc=duanxiongchun@bytedance.com \
    --cc=guro@fb.com \
    --cc=hannes@cmpxchg.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=shakeelb@google.com \
    --cc=vdavydov.dev@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).