From: Oleg Nesterov <oleg@redhat.com>
To: Josh Triplett <josh@joshtriplett.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Kees Cook <keescook@chromium.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
"H. Peter Anvin" <hpa@zytor.com>, Rik van Riel <riel@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Thiago Macieira <thiago.macieira@intel.com>,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
linux-fsdevel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH v2 5/7] clone4: Add a CLONE_AUTOREAP flag to automatically reap the child process
Date: Sun, 15 Mar 2015 15:52:23 +0100 [thread overview]
Message-ID: <20150315145223.GA21887@redhat.com> (raw)
In-Reply-To: <6d002995485d446e659105f6931307f3e532ce89.1426376419.git.josh@joshtriplett.org>
On 03/15, Josh Triplett wrote:
>
> Add a CLONE_AUTOREAP flag to request this behavior unconditionally,
Yes, CLONE_AUTOREAP is much better. And I agree (mostly) with that
we should rely on do_notify_parent().
Howver the patch still doesn't look right. First of all, ->autoreap
should be per-process, not per-thread. And there are ptrace/mt issues,
it seems. Just for example, we should avoid EXIT_TRACE if autoreap in
wait_task_zombie() even if we are going to re-notify parent.
Yes... and other problems with ptrace. So let me nack this patch for
the moment ;) But let me repeat that personally I agree with this
change "in general".
EXCEPT: do we really want SIGCHLD from the exiting child? I think we
do not. I won't really argue though, but this should be discussed and
documented. IIUC, with your patch it is still sent.
Josh, please give me some time to think and re-check, I'll write another
email next week. I am not sure this is really needed, but it seems to
me that we need the preparation patch to make this change clear/simple.
Oleg.
next prev parent reply other threads:[~2015-03-15 14:54 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-15 7:59 [PATCH v2 0/7] CLONE_FD: Task exit notification via file descriptor Josh Triplett
2015-03-15 7:59 ` [PATCH v2 1/7] clone: Support passing tls argument via C rather than pt_regs magic Josh Triplett
2015-03-15 7:59 ` [PATCH v2 2/7] x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit Josh Triplett
2015-03-15 7:59 ` [PATCH v2 3/7] Introduce a new clone4 syscall with more flag bits and extensible arguments Josh Triplett
2015-03-23 14:11 ` David Drysdale
2015-03-23 15:05 ` josh
2015-03-31 14:41 ` David Drysdale
2015-03-15 7:59 ` [PATCH v2 4/7] kernel/fork.c: Pass arguments to _do_fork and copy_process using clone4_args Josh Triplett
2015-03-15 8:00 ` [PATCH v2 5/7] clone4: Add a CLONE_AUTOREAP flag to automatically reap the child process Josh Triplett
2015-03-15 14:52 ` Oleg Nesterov [this message]
2015-03-15 17:18 ` Josh Triplett
2015-03-15 19:55 ` Oleg Nesterov
2015-03-15 23:34 ` Josh Triplett
2015-03-20 18:14 ` Oleg Nesterov
2015-03-20 18:46 ` Thiago Macieira
2015-03-20 19:09 ` Oleg Nesterov
2015-03-20 21:10 ` josh
2015-03-15 8:00 ` [PATCH v2 6/7] signal: Factor out a helper function to process task_struct exit_code Josh Triplett
2015-03-15 8:00 ` [PATCH v2 7/7] clone4: Add a CLONE_FD flag to get task exit notification via fd Josh Triplett
2015-03-23 17:38 ` David Drysdale
2015-03-25 14:53 ` Josh Triplett
2015-04-06 8:30 ` Sergey Senozhatsky
2015-04-06 9:31 ` Josh Triplett
2015-03-15 8:00 ` [PATCH v2 man-pages] clone4.2: New manpage documenting clone4(2) Josh Triplett
2015-03-15 8:04 ` [PATCH v2 0/7] CLONE_FD: Task exit notification via file descriptor Josh Triplett
2015-03-16 21:44 ` Kees Cook
2015-03-16 22:14 ` Thiago Macieira
2015-03-16 22:36 ` Kees Cook
2015-03-16 22:50 ` Thiago Macieira
2015-03-16 23:26 ` Kees Cook
2015-03-16 23:35 ` josh
2015-03-16 23:29 ` josh
2015-03-17 0:49 ` Thiago Macieira
2015-03-23 14:12 ` David Drysdale
2015-03-23 15:03 ` josh
2015-03-16 23:25 ` josh
2015-03-31 20:08 ` Jonathan Corbet
2015-03-31 22:02 ` josh
2015-04-01 7:24 ` Jonathan Corbet
2015-04-09 2:19 ` Josh Triplett
2015-05-29 7:43 ` Florian Weimer
2015-05-29 20:27 ` Thiago Macieira
2015-06-15 10:06 ` Florian Weimer
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