From: Michal Hocko <mhocko@suse.cz>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: linux-mm@kvack.org, Hugh Dickins <hughd@google.com>,
Tejun Heo <tj@kernel.org>,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [patch 7/9] mm: memcontrol: do not acquire page_cgroup lock for kmem pages
Date: Wed, 28 May 2014 13:33:28 +0200 [thread overview]
Message-ID: <20140528113328.GG9895@dhcp22.suse.cz> (raw)
In-Reply-To: <20140527195342.GD2878@cmpxchg.org>
On Tue 27-05-14 15:53:42, Johannes Weiner wrote:
> On Fri, May 23, 2014 at 03:39:38PM +0200, Michal Hocko wrote:
[...]
> > > if (!PageCgroupUsed(pc))
> > > return;
> > >
> > > - lock_page_cgroup(pc);
> > > - if (PageCgroupUsed(pc)) {
> > > - memcg = pc->mem_cgroup;
> > > - ClearPageCgroupUsed(pc);
> > > - }
> > > - unlock_page_cgroup(pc);
> >
> > maybe add
> > WARN_ON_ONCE(pc->flags != PCG_USED);
> >
> > to check for an unexpected flags usage in the kmem path?
>
> There is no overlap between page types that use PCG_USED and those
> that don't. What would be the value of adding this?
I meant it as an early warning that something bad is going on.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2014-05-28 11:33 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-30 20:25 [patch 0/9] mm: memcontrol: naturalize charge lifetime Johannes Weiner
2014-04-30 20:25 ` [patch 1/9] mm: memcontrol: fold mem_cgroup_do_charge() Johannes Weiner
2014-04-30 20:25 ` [patch 2/9] mm: memcontrol: rearrange charging fast path Johannes Weiner
2014-05-07 14:33 ` Michal Hocko
2014-05-08 18:22 ` Johannes Weiner
2014-05-12 7:59 ` Michal Hocko
2014-04-30 20:25 ` [patch 3/9] mm: memcontrol: retry reclaim for oom-disabled and __GFP_NOFAIL charges Johannes Weiner
2014-05-07 14:43 ` Michal Hocko
2014-05-08 18:28 ` Johannes Weiner
2014-04-30 20:25 ` [patch 4/9] mm: memcontrol: catch root bypass in move precharge Johannes Weiner
2014-05-07 14:55 ` Michal Hocko
2014-05-08 18:30 ` Johannes Weiner
2014-04-30 20:25 ` [patch 5/9] mm: memcontrol: use root_mem_cgroup res_counter Johannes Weiner
2014-05-07 15:14 ` Michal Hocko
2014-04-30 20:25 ` [patch 6/9] mm: memcontrol: remove ordering between pc->mem_cgroup and PageCgroupUsed Johannes Weiner
2014-05-23 13:20 ` Michal Hocko
2014-05-27 19:45 ` Johannes Weiner
2014-05-28 11:31 ` Michal Hocko
2014-04-30 20:25 ` [patch 7/9] mm: memcontrol: do not acquire page_cgroup lock for kmem pages Johannes Weiner
2014-05-23 13:39 ` Michal Hocko
2014-05-23 13:40 ` Michal Hocko
2014-05-23 14:29 ` Vladimir Davydov
2014-05-27 19:53 ` Johannes Weiner
2014-05-28 11:33 ` Michal Hocko [this message]
2014-04-30 20:25 ` [patch 8/9] mm: memcontrol: rewrite charge API Johannes Weiner
2014-05-23 14:18 ` Michal Hocko
2014-05-23 14:54 ` Michal Hocko
2014-05-23 15:18 ` Michal Hocko
2014-05-27 20:05 ` Johannes Weiner
2014-05-28 11:37 ` Michal Hocko
2014-04-30 20:25 ` [patch 9/9] mm: memcontrol: rewrite uncharge API Johannes Weiner
2014-05-04 14:32 ` Johannes Weiner
2014-05-27 7:43 ` Kamezawa Hiroyuki
2014-05-27 18:59 ` Johannes Weiner
2014-05-02 11:26 ` [patch 0/9] mm: memcontrol: naturalize charge lifetime Michal Hocko
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=20140528113328.GG9895@dhcp22.suse.cz \
--to=mhocko@suse.cz \
--cc=cgroups@vger.kernel.org \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=tj@kernel.org \
/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
all inboxes | Powered by JetHome®