From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: Linus Torvalds <torvalds@osdl.org>,
<lse-tech@lists.sourceforge.net>, <linux-kernel@vger.kernel.org>
Subject: Re: [RFC,PATCH] use rcu for fasync_lock
Date: Fri, 26 Dec 2003 00:11:51 +0900 [thread overview]
Message-ID: <873cb9c4p4.fsf@devron.myhome.or.jp> (raw)
In-Reply-To: <Pine.LNX.4.44.0312250213120.13730-100000@dbl.q-ag.de>
Manfred Spraul <manfred@colorfullife.com> writes:
> --- 2.6/fs/fcntl.c 2003-12-04 19:44:38.000000000 +0100
> +++ build-2.6/fs/fcntl.c 2003-12-24 00:15:16.000000000 +0100
> @@ -609,9 +609,15 @@
>
> void kill_fasync(struct fasync_struct **fp, int sig, int band)
> {
> - read_lock(&fasync_lock);
> - __kill_fasync(*fp, sig, band);
> - read_unlock(&fasync_lock);
> + /* First a quick test without locking: usually
> + * the list is empty.
> + */
> + if (*fp) {
> + read_lock(&fasync_lock);
> + /* reread *fp after obtaining the lock */
> + __kill_fasync(*fp, sig, band);
> + read_unlock(&fasync_lock);
> + }
> }
Looks good to me. This should be the enough effect for usual path.
Thanks.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
prev parent reply other threads:[~2003-12-25 15:12 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-20 18:20 [RFC,PATCH] use rcu for fasync_lock Manfred Spraul
2003-12-20 21:10 ` [Lse-tech] " Stephen Hemminger
2003-12-20 21:35 ` Manfred Spraul
2003-12-21 11:36 ` Jamie Lokier
2003-12-21 12:40 ` Manfred Spraul
2003-12-21 14:14 ` Jamie Lokier
2003-12-21 14:59 ` Manfred Spraul
2003-12-21 15:08 ` Jamie Lokier
2004-01-02 21:15 ` Bill Davidsen
2004-01-02 22:41 ` Jamie Lokier
2004-01-03 1:09 ` Mike Fedyk
2004-01-03 21:28 ` Jamie Lokier
2004-01-04 19:01 ` Ingo Oeser
2004-01-04 19:20 ` Davide Libenzi
2004-01-05 21:17 ` Ingo Oeser
2004-01-05 22:24 ` Davide Libenzi
2003-12-21 15:14 ` Davide Libenzi
2003-12-21 15:17 ` Davide Libenzi
2003-12-21 15:28 ` Jamie Lokier
2003-12-21 18:38 ` OGAWA Hirofumi
2003-12-21 19:14 ` Manfred Spraul
2003-12-21 20:51 ` Linus Torvalds
2003-12-21 21:08 ` Manfred Spraul
2003-12-21 21:19 ` Linus Torvalds
2003-12-21 21:54 ` Manfred Spraul
2003-12-21 22:05 ` Linus Torvalds
2003-12-25 1:21 ` Manfred Spraul
2003-12-25 15:11 ` OGAWA Hirofumi [this message]
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