linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Pekka Enberg <penberg@cs.helsinki.fi>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>, Jens Axboe <axboe@kernel.dk>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch 3/6] fs: remove dependency on __GFP_NOFAIL
Date: Sat, 24 Jul 2010 00:12:32 +0300	[thread overview]
Message-ID: <AANLkTikESJCnC2yYJ8dLFEF+2P7azfiqv2-sSr0D51Y9@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1007231244440.5317@chino.kir.corp.google.com>

On Fri, Jul 23, 2010 at 10:51 PM, David Rientjes <rientjes@google.com> wrote:
> On Fri, 23 Jul 2010, Andrew Morton wrote:
>
>> > The kmalloc() in bio_integrity_prep() is failable, so remove __GFP_NOFAIL
>> > from its mask.
>> >
>> > Cc: Jens Axboe <jens.axboe@oracle.com>
>> > Signed-off-by: David Rientjes <rientjes@google.com>
>> > ---
>> >  fs/bio-integrity.c |    2 +-
>> >  1 files changed, 1 insertions(+), 1 deletions(-)
>> >
>> > diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
>> > --- a/fs/bio-integrity.c
>> > +++ b/fs/bio-integrity.c
>> > @@ -413,7 +413,7 @@ int bio_integrity_prep(struct bio *bio)
>> >
>> >     /* Allocate kernel buffer for protection data */
>> >     len = sectors * blk_integrity_tuple_size(bi);
>> > -   buf = kmalloc(len, GFP_NOIO | __GFP_NOFAIL | q->bounce_gfp);
>> > +   buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
>> >     if (unlikely(buf == NULL)) {
>> >             printk(KERN_ERR "could not allocate integrity buffer\n");
>> >             return -EIO;
>>
>>                         ^^^  what?
>
> Right, I'm not sure why that decision was made, but it looks like it can
> be changed over to -ENOMEM without harming anything.  I'm concerned that
> the printk will spam the kernel log endlessly, though, if we're really oom
> and GFP_NOIO has no hope of freeing memory.  This code has never been
> active, so I'd like to wait for some feedback from Al and Jens (now with a
> corrected email address, jens.axboe@oracle.com bounced) to see if we want
> to return -ENOMEM, if the printk is really necessary, and if it would be
> better to just convert this to a loop with a congestion_wait() instead of
> returning from bio_integrity_prep().

Btw, you probably want __GFP_NOWARN here if you expect the allocation
to fail under normal conditions.

--
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:[~2010-07-23 21:12 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-21  2:44 [patch 0/6] remove dependency on __GFP_NOFAIL for failable allocations David Rientjes
2010-07-21  2:44 ` [patch 1/6] sparc: remove dependency on __GFP_NOFAIL David Rientjes
2010-07-21  3:31   ` David Miller
2010-07-21  9:41     ` David Rientjes
2010-07-21  2:44 ` [patch 2/6] infiniband: " David Rientjes
2010-07-21  3:19   ` Steve Wise
2010-07-21 17:55     ` Roland Dreier
2010-07-21  2:45 ` [patch 3/6] fs: " David Rientjes
2010-07-23 19:36   ` Andrew Morton
2010-07-23 19:51     ` David Rientjes
2010-07-23 21:12       ` Pekka Enberg [this message]
2010-07-21  2:45 ` [patch 4/6] gfs2: " David Rientjes
2010-07-21  9:24   ` Steven Whitehouse
2010-07-21  9:31     ` David Rientjes
2010-07-21  2:45 ` [patch 6/6] jbd2: " David Rientjes
2010-07-22 14:14   ` Ted Ts'o
2010-07-22 18:09     ` David Rientjes
2010-07-22 23:09       ` Ted Ts'o
2010-07-22 23:24         ` David Rientjes
2010-07-23 14:10           ` Ted Ts'o
2010-07-23 14:57             ` Jan Kara
2010-07-23 15:05               ` Ted Ts'o
2010-07-23 15:32                 ` Jan Kara
2010-07-23 19:40                 ` David Rientjes
2010-07-23 19:52                   ` Ted Ts'o
2010-07-21 19:26 ` [patch 5/6] jbd: " David Rientjes

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=AANLkTikESJCnC2yYJ8dLFEF+2P7azfiqv2-sSr0D51Y9@mail.gmail.com \
    --to=penberg@cs.helsinki.fi \
    --cc=akpm@linux-foundation.org \
    --cc=axboe@kernel.dk \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=rientjes@google.com \
    --cc=viro@zeniv.linux.org.uk \
    /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