public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Benjamin LaHaise <bcrl@kvack.org>
To: Davide Libenzi <davidel@xmailserver.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Trond Myklebust <trond.myklebust@fys.uio.no>,
	Andrew Morton <akpm@linux-foundation.org>,
	Eric Dumazet <dada1@cosmosbay.com>,
	linux-aio <linux-aio@kvack.org>,
	zach.brown@oracle.com
Subject: Re: [patch] eventfd - remove fput() call from possible IRQ context
Date: Sun, 15 Mar 2009 13:44:45 -0400	[thread overview]
Message-ID: <20090315174445.GD18305@kvack.org> (raw)
In-Reply-To: <alpine.DEB.1.10.0903141826120.3888@makko.or.mcafeemobile.com>

On Sat, Mar 14, 2009 at 06:36:34PM -0700, Davide Libenzi wrote:
> The following patch remove a possible source of fput() call from inside 
> IRQ context. Myself, like Eric, wasn't able to reproduce an fput() call 
> from IRQ context, but conceptually the bug is there.
> This patch adds an optimization similar to the one we already do on 
> ->ki_filp, on ->ki_eventfd. Playing with ->f_count directly is not pretty 
> in general, but the alternative here would be to add a brand new delayed 
> fput() infrastructure, that I'm not sure is worth it.

This looks reasonably sane, the only concern I have with it is that I think 
it logically makes more sense to use the same convention for fi_filp and 
ki_eventfd, as the different in IS_ERR vs checking for NULL is a bit 
confusing.  Aside from that, it looks like it should fix the problem 
correctly.

		-ben

  reply	other threads:[~2009-03-15 17:44 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-09 15:49 [patch] aio: remove aio-max-nr and instead use the memlock rlimit to limit the number of pages pinned for the aio completion ring Jeff Moyer
2009-03-09 15:54 ` [patch] factor out checks against the memlock rlimit Jeff Moyer
2009-03-09 15:59 ` [patch] man-pages: add documentation about the memlock implications of io_setup Jeff Moyer
2009-03-09 16:45   ` Michael Kerrisk
2009-03-09 16:48   ` Michael Kerrisk
2009-03-09 20:44     ` Jeff Moyer
2009-03-09 16:18 ` [patch] aio: remove aio-max-nr and instead use the memlock rlimit to limit the number of pages pinned for the aio completion ring Avi Kivity
2009-03-09 17:57   ` Jeff Moyer
2009-03-09 19:45     ` Avi Kivity
2009-03-09 20:36       ` Jamie Lokier
2009-03-10  8:36         ` Avi Kivity
2009-03-09 20:31     ` Eric Dumazet
2009-03-12  2:39       ` Eric Dumazet
2009-03-12  2:44         ` Benjamin LaHaise
2009-03-12  3:24           ` Eric Dumazet
2009-03-12  3:29             ` Benjamin LaHaise
2009-03-12  3:33               ` Eric Dumazet
2009-03-12  3:36                 ` Benjamin LaHaise
2009-03-12  3:40                   ` Eric Dumazet
2009-03-12  3:09         ` Eric Dumazet
2009-03-12  5:18           ` [PATCH] fs: fput() can be called from interrupt context Eric Dumazet
2009-03-12  5:42             ` [PATCH] aio: " Eric Dumazet
2009-03-12  5:47             ` [PATCH] fs: " Andrew Morton
2009-03-12  6:10               ` Eric Dumazet
2009-03-12  6:39                 ` Andrew Morton
2009-03-12 13:39                   ` Davide Libenzi
2009-03-13 22:34                     ` Davide Libenzi
2009-03-13 22:43                       ` Eric Dumazet
2009-03-13 23:28                     ` Trond Myklebust
2009-03-14  1:40                       ` Davide Libenzi
2009-03-14  4:02                         ` Trond Myklebust
2009-03-14 14:32                           ` Davide Libenzi
2009-03-15  1:36                             ` [patch] eventfd - remove fput() call from possible IRQ context Davide Libenzi
2009-03-15 17:44                               ` Benjamin LaHaise [this message]
2009-03-15 20:08                                 ` [patch] eventfd - remove fput() call from possible IRQ context (2nd rev) Davide Libenzi
2009-03-16 17:25                                   ` Jamie Lokier
2009-03-16 18:36                                     ` Davide Libenzi
2009-03-18 14:22                                   ` Jeff Moyer
2009-03-18 14:46                                     ` Davide Libenzi
2009-03-18 14:55                                     ` Eric Dumazet
2009-03-18 15:25                                       ` Jeff Moyer
2009-03-18 15:43                                         ` Eric Dumazet
2009-03-18 16:13                                           ` Jeff Moyer
2009-03-18 17:25                                     ` [patch] eventfd - remove fput() call from possible IRQ context (3rd rev) Davide Libenzi
2009-03-18 17:34                                       ` Jeff Moyer
2009-03-12 19:22                   ` [PATCH] fs: fput() can be called from interrupt context Eric Dumazet
2009-03-12 20:21                     ` Andrew Morton
2009-03-09 22:36 ` [patch] aio: remove aio-max-nr and instead use the memlock rlimit to limit the number of pages pinned for the aio completion ring Andrew Morton
2009-03-10 13:43   ` Jeff Moyer

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=20090315174445.GD18305@kvack.org \
    --to=bcrl@kvack.org \
    --cc=akpm@linux-foundation.org \
    --cc=dada1@cosmosbay.com \
    --cc=davidel@xmailserver.org \
    --cc=linux-aio@kvack.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=trond.myklebust@fys.uio.no \
    --cc=zach.brown@oracle.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