From: Tejun Heo <tj@kernel.org>
To: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
vda.linux@googlemail.com, linux-kernel@vger.kernel.org,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
indan@nul.nu
Subject: Re: waitpid(WNOHANG) should report SIGCHLD-notified signals [Re: [PATCH 09/11] job control: reorganize wait_task_stopped()]
Date: Mon, 16 May 2011 14:46:25 +0200 [thread overview]
Message-ID: <20110516124625.GV23665@htj.dyndns.org> (raw)
In-Reply-To: <20110516123930.GA11933@host1.jankratochvil.net>
Hello,
On Mon, May 16, 2011 at 02:39:30PM +0200, Jan Kratochvil wrote:
> > The above wouldn't be linux kernel's top design concerns, right?
>
> They are - as without threads one needs reliable WNOHANG - while which you say
> it is not reliable.
As I wrote before, I think it's reliable for ptrace. The problematic
ones are transitions between continued and stopped and running and I
don't think it would affect ptrace.
> > It's not like new interface is gonna break that, but I think it's gonna be
> > more fragile. Well, it shouldn't be worse than now.
>
> BTW I really do not think this WNOHANG issue is anyhow related to this whole
> discussion.
Probably not but I've seen gdb going out of sync with the expected
state of the tracee. Dunno whether it was kernel bug or gdb bug but
it seemed pretty fragile and adding group stop notifications might
make it a bit more difficult. I don't know. It was just my five
cents. Feel free to ignore.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-05-16 12:46 UTC|newest]
Thread overview: 115+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-08 15:48 [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification Tejun Heo
2011-05-08 15:48 ` [PATCH 01/11] job control: rename signal->group_stop and flags to jobctl and rearrange flags Tejun Heo
2011-05-08 15:48 ` [PATCH 02/11] ptrace: implement PTRACE_SEIZE Tejun Heo
2011-05-09 16:18 ` Oleg Nesterov
2011-05-10 9:46 ` Tejun Heo
2011-05-10 13:20 ` Oleg Nesterov
2011-05-10 13:47 ` Tejun Heo
2011-05-10 18:19 ` Oleg Nesterov
2011-05-15 15:56 ` PTRACE_SEIZE should not stop [Re: [PATCH 02/11] ptrace: implement PTRACE_SEIZE] Jan Kratochvil
2011-05-15 16:26 ` Tejun Heo
2011-05-15 17:15 ` Jan Kratochvil
2011-05-15 17:25 ` Tejun Heo
2011-05-15 19:48 ` Jan Kratochvil
2011-05-16 8:31 ` Tejun Heo
2011-05-16 12:26 ` Jan Kratochvil
2011-05-16 12:42 ` Tejun Heo
2011-05-16 13:03 ` Jan Kratochvil
2011-05-16 13:51 ` Tejun Heo
2011-05-16 13:21 ` Jan Kratochvil
2011-05-16 13:45 ` Tejun Heo
2011-05-16 13:48 ` Jan Kratochvil
2011-05-16 13:54 ` Tejun Heo
2011-05-08 15:48 ` [PATCH 03/11] ptrace: ptrace_check_attach(): rename @kill to @ignore_state and add comments Tejun Heo
2011-05-08 15:48 ` [PATCH 04/11] ptrace: implement PTRACE_INTERRUPT Tejun Heo
2011-05-08 21:58 ` Denys Vlasenko
2011-05-09 10:09 ` Tejun Heo
2011-05-09 10:55 ` Denys Vlasenko
2011-05-09 16:58 ` Oleg Nesterov
2011-05-10 9:50 ` Tejun Heo
2011-05-10 14:06 ` Oleg Nesterov
2011-05-10 14:20 ` Tejun Heo
2011-05-10 18:08 ` Oleg Nesterov
2011-05-11 8:29 ` Tejun Heo
2011-05-12 17:06 ` Oleg Nesterov
2011-05-12 17:21 ` Tejun Heo
2011-05-10 21:59 ` Denys Vlasenko
2011-05-11 9:19 ` Tejun Heo
2011-05-11 12:23 ` Denys Vlasenko
2011-05-11 13:22 ` Tejun Heo
2011-05-11 16:20 ` Bryan Donlan
2011-05-11 19:24 ` Tejun Heo
2011-05-15 16:10 ` PTRACE_DETACH without stop [Re: [PATCH 04/11] ptrace: implement PTRACE_INTERRUPT] Jan Kratochvil
2011-05-15 16:35 ` Tejun Heo
2011-05-15 17:39 ` Jan Kratochvil
2011-05-16 9:01 ` Tejun Heo
2011-05-16 12:08 ` Jan Kratochvil
2011-05-16 12:24 ` Tejun Heo
2011-05-08 15:48 ` [PATCH 05/11] ptrace: restructure ptrace_getsiginfo() Tejun Heo
2011-05-08 15:49 ` [PATCH 06/11] ptrace: make group stop state visible via PTRACE_GETSIGINFO Tejun Heo
2011-05-10 16:55 ` Oleg Nesterov
2011-05-10 17:11 ` Oleg Nesterov
2011-05-11 8:08 ` Tejun Heo
2011-05-12 16:47 ` Oleg Nesterov
2011-05-12 17:15 ` Tejun Heo
2011-05-08 15:49 ` [PATCH 07/11] ptrace: add JOBCTL_TRAPPED Tejun Heo
2011-05-08 15:49 ` [PATCH 08/11] ptrace: move fallback JOBCTL_TRAPPING clearing to get_signal_to_deliver() Tejun Heo
2011-05-11 15:48 ` Oleg Nesterov
2011-05-11 19:17 ` Tejun Heo
2011-05-12 15:40 ` Oleg Nesterov
2011-05-08 15:49 ` [PATCH 09/11] job control: reorganize wait_task_stopped() Tejun Heo
2011-05-11 15:48 ` Oleg Nesterov
2011-05-11 19:29 ` Tejun Heo
2011-05-12 15:42 ` Oleg Nesterov
2011-05-12 16:02 ` Tejun Heo
2011-05-12 17:25 ` Oleg Nesterov
2011-05-12 17:32 ` Tejun Heo
2011-05-12 17:33 ` Tejun Heo
2011-05-12 18:33 ` Oleg Nesterov
2011-05-13 8:46 ` Tejun Heo
2011-05-13 17:21 ` Oleg Nesterov
2011-05-14 10:56 ` Tejun Heo
2011-05-15 14:40 ` waitpid(WNOHANG) should report SIGCHLD-notified signals [Re: [PATCH 09/11] job control: reorganize wait_task_stopped()] Jan Kratochvil
2011-05-15 16:47 ` Tejun Heo
2011-05-15 17:01 ` Tejun Heo
2011-05-15 17:47 ` Jan Kratochvil
2011-05-16 9:13 ` Tejun Heo
2011-05-16 12:11 ` Jan Kratochvil
2011-05-16 12:27 ` Tejun Heo
2011-05-16 12:39 ` Jan Kratochvil
2011-05-16 12:46 ` Tejun Heo [this message]
2011-05-08 15:49 ` [PATCH 10/11] ptrace: move JOBCTL_TRAPPING wait to wait(2) and ptrace_check_attach() Tejun Heo
2011-05-11 16:49 ` Oleg Nesterov
2011-05-11 17:00 ` Oleg Nesterov
2011-05-11 19:45 ` Tejun Heo
2011-05-11 19:53 ` Tejun Heo
2011-05-12 10:23 ` Tejun Heo
2011-05-12 16:06 ` Oleg Nesterov
2011-05-12 15:59 ` Oleg Nesterov
2011-05-12 16:07 ` Tejun Heo
2011-05-12 18:20 ` Oleg Nesterov
2011-05-13 9:13 ` Tejun Heo
2011-05-13 18:34 ` Oleg Nesterov
2011-05-08 15:49 ` [PATCH 11/11] ptrace: implement group stop notification for ptracer Tejun Heo
2011-05-08 22:42 ` Denys Vlasenko
2011-05-09 10:10 ` Tejun Heo
2011-05-10 22:37 ` Denys Vlasenko
2011-05-11 9:05 ` Tejun Heo
2011-05-11 12:01 ` Denys Vlasenko
2011-05-11 13:13 ` Tejun Heo
2011-05-11 19:58 ` Oleg Nesterov
2011-05-11 20:18 ` Tejun Heo
2011-05-11 20:21 ` Tejun Heo
2011-05-12 10:24 ` Tejun Heo
2011-05-15 14:02 ` getter PTRACE_GETSIGINFO should not modify anything [Re: [PATCH 11/11] ptrace: implement group stop notification for ptracer] Jan Kratochvil
2011-05-15 14:28 ` Tejun Heo
2011-05-15 17:17 ` Jan Kratochvil
2011-05-15 17:28 ` Tejun Heo
2011-05-15 20:06 ` Jan Kratochvil
2011-05-16 8:43 ` Tejun Heo
2011-05-16 12:17 ` Jan Kratochvil
2011-05-16 12:56 ` Tejun Heo
2011-05-16 13:00 ` Ingo Molnar
2011-05-08 22:27 ` [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification Denys Vlasenko
2011-05-09 9:48 ` Tejun Heo
2011-05-15 13:55 ` ptrace-testsuite status [Re: [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification] Jan Kratochvil
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=20110516124625.GV23665@htj.dyndns.org \
--to=tj@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=indan@nul.nu \
--cc=jan.kratochvil@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=torvalds@linux-foundation.org \
--cc=vda.linux@googlemail.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;
as well as URLs for NNTP newsgroup(s).