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From: Colin Walters <walters@verbum.org>
To: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>,
	akpm@linux-foundation.org, viro@zeniv.linux.org.uk,
	torvalds@linux-foundation.org, drepper@gmail.com,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] nextfd(2)
Date: Tue, 03 Apr 2012 15:21:13 -0400	[thread overview]
Message-ID: <1333480873.10230.35.camel@lenny> (raw)
In-Reply-To: <CAHGf_=pgpRrQA3-YVtS=h-Bjq2LyTFmYtKGxxWgwP0XWexnh2g@mail.gmail.com>

On Mon, 2012-04-02 at 16:17 -0700, KOSAKI Motohiro wrote:

> we can only call async-signal-safe functions after fork() when multi threads and
> opendir() call malloc() internally.
> 
> As far as I know, OpenJDK has a such fork-readdir-exec code and it can
> make deadlock
> when spawnning a new process. Unfortunately Java language perfeter to
> make a lot of threads rather than other language.
> 
> This patch can solve such multi threaded case.
> 
> offtopic, glibc malloc is a slightly clever. It reinitialize its
> internal lock when fork by
> using thread_atfork() hook. It mean glibc malloc can be used after
> fork() and the
> technique can avoid this issue. 

Yeah, a *lot* of code out there depends on this glibc malloc
implementation detail.  We uncovered our dependency on this in
GNOME a while back while investigating getenv/setenv/fork and threads:
https://bugzilla.gnome.org/show_bug.cgi?id=659326



  parent reply	other threads:[~2012-04-03 19:21 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-01 12:57 [PATCH] nextfd(2) Alexey Dobriyan
2012-04-01 13:58 ` Konstantin Khlebnikov
2012-04-01 21:30   ` Alexey Dobriyan
2012-04-02  0:09   ` Alan Cox
2012-04-02  8:38     ` Konstantin Khlebnikov
2012-04-02  9:26       ` Cyrill Gorcunov
2012-04-01 15:43 ` Eric Dumazet
2012-04-01 21:31   ` Alexey Dobriyan
2012-04-01 21:36   ` Alan Cox
2012-04-01 17:20 ` Linus Torvalds
2012-04-01 18:28 ` Valentin Nechayev
2012-04-01 21:33   ` Alexey Dobriyan
2012-04-01 19:21 ` Arnd Bergmann
2012-04-01 21:35   ` Alexey Dobriyan
2012-04-01 22:05   ` H. Peter Anvin
2012-04-04 12:13     ` Arnd Bergmann
2012-04-01 22:03 ` H. Peter Anvin
2012-04-01 22:13   ` H. Peter Anvin
2012-04-02  0:08   ` Alan Cox
2012-04-30  9:58     ` Valentin Nechayev
2012-04-02  1:19   ` Kyle Moffett
2012-04-02  1:37     ` H. Peter Anvin
2012-04-02 11:37     ` Ulrich Drepper
2012-04-06  9:54   ` Alexey Dobriyan
2012-04-06 15:27     ` Colin Walters
2012-04-06 16:14     ` H. Peter Anvin
2012-04-06 20:16       ` Alexey Dobriyan
2012-04-06 20:33         ` H. Peter Anvin
2012-04-06 21:02         ` H. Peter Anvin
2012-04-12 10:54           ` Alexey Dobriyan
2012-04-12 11:11             ` Alan Cox
2012-04-12 13:35               ` Alexey Dobriyan
2012-04-12 13:51                 ` H. Peter Anvin
2012-04-12 19:21                   ` Alexey Dobriyan
2012-04-12 14:09               ` Eric Dumazet
2012-04-06 16:23     ` H. Peter Anvin
2012-04-07 21:21       ` Ben Pfaff
2012-04-11  0:12         ` KOSAKI Motohiro
2012-04-11  0:09       ` KOSAKI Motohiro
2012-04-11 17:58         ` H. Peter Anvin
2012-04-11 18:04           ` Linus Torvalds
2012-04-11 18:11             ` H. Peter Anvin
2012-04-11 19:46               ` KOSAKI Motohiro
2012-04-11 19:49                 ` H. Peter Anvin
2012-04-11 20:23                   ` KOSAKI Motohiro
2012-04-11 20:32                     ` H. Peter Anvin
2012-04-17 18:12                       ` KOSAKI Motohiro
2012-04-11 18:00         ` H. Peter Anvin
2012-04-11 19:20           ` KOSAKI Motohiro
2012-04-11 19:22             ` H. Peter Anvin
2012-04-11 19:26               ` KOSAKI Motohiro
2012-04-11 19:28                 ` H. Peter Anvin
2012-04-11 19:31                   ` KOSAKI Motohiro
2012-04-11 19:32                     ` H. Peter Anvin
2012-04-02 23:17 ` KOSAKI Motohiro
2012-04-02 23:56   ` H. Peter Anvin
2012-04-04 11:51     ` Ulrich Drepper
2012-04-04 16:38       ` KOSAKI Motohiro
2012-04-04 16:43         ` Ulrich Drepper
2012-04-04 17:07           ` KOSAKI Motohiro
2012-04-04 17:49             ` Ulrich Drepper
2012-04-04 18:08               ` KOSAKI Motohiro
2012-04-04 16:31     ` KOSAKI Motohiro
2012-04-04 17:10       ` Colin Walters
2012-04-04 17:25         ` Colin Walters
2012-04-04 23:35         ` KOSAKI Motohiro
2012-04-04 18:44       ` H. Peter Anvin
2012-04-03 19:21   ` Colin Walters [this message]
2012-04-04  3:01 ` Al Viro
2012-04-04 17:10   ` KOSAKI Motohiro

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