linux-ext4.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Nikolay Borisov <kernel@kyup.com>
To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	Theodore Ts'o <tytso@mit.edu>
Cc: Michal Hocko <mhocko@suse.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Dmitry Monakhov <dmonakhov@virtuozzo.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH RFC] ext4: use __GFP_NOFAIL in ext4_free_blocks()
Date: Thu, 25 Feb 2016 11:01:32 +0200	[thread overview]
Message-ID: <56CEC2EC.5000506@kyup.com> (raw)
In-Reply-To: <20160224170912.2195.8153.stgit@buzz>



On 02/24/2016 07:09 PM, Konstantin Khlebnikov wrote:
> This might be unexpected but pages allocated for sbi->s_buddy_cache are
> charged to current memory cgroup. So, GFP_NOFS allocation could fail if
> current task has been killed by OOM or if current memory cgroup has no
> free memory left. Block allocator cannot handle such failures here yet.
> 
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

Adding new users of GFP_NOFAIL is deprecated. Where exactly does the
block allocator fail, I skimmed the code and failing ext4_mb_load_buddy
seems to be handled at all call sites. There are some BUG_ONs but from
the comments there I guess they should occur when we try to find a page
and not allocate a new one?

--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2016-02-25  9:01 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-24 17:09 [PATCH RFC] ext4: use __GFP_NOFAIL in ext4_free_blocks() Konstantin Khlebnikov
2016-02-25  9:01 ` Nikolay Borisov [this message]
2016-02-25  9:08   ` Michal Hocko
2016-02-25  9:12     ` Nikolay Borisov
2016-02-25 10:27       ` Michal Hocko
2016-03-13 21:30 ` Theodore Ts'o

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=56CEC2EC.5000506@kyup.com \
    --to=kernel@kyup.com \
    --cc=dmonakhov@virtuozzo.com \
    --cc=hannes@cmpxchg.org \
    --cc=khlebnikov@yandex-team.ru \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=tytso@mit.edu \
    /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).