From: Oleg Nesterov <oleg@redhat.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
tromey@redhat.com, Stephen Rothwell <sfr@canb.auug.org.au>,
Kyle Moffett <kyle@moffetthome.net>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Peter Zijlstra <peterz@infradead.org>,
Fr??d??ric Weisbecker <fweisbec@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
LKML <linux-kernel@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
"Frank Ch. Eigler" <fche@redhat.com>,
linux-next@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
utrace-devel@redhat.com, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: linux-next: add utrace tree
Date: Tue, 26 Jan 2010 22:53:49 +0100 [thread overview]
Message-ID: <20100126215349.GB19146@redhat.com> (raw)
In-Reply-To: <20100126210232.GF6567@basil.fritz.box>
On 01/26, Andi Kleen wrote:
>
> But when I did that i couldn't come up with a good scenario
> where multiple debuggers actually make sense. In a sense
> being a debugger is really a very "intimate" thing for process. Do you
> really want to have multiple of them messing with each other?
>
> If yes how would they know what to touch and what not?
Yes, multiple debuggers can confuse each other if they change
the state of debuggee simultaneously. The user should do this ;)
> Can you think of any scenario where multiple debuggers
> on a process make sense?
Simple example. Try to debug/strace strace ot gdb itself. Not trivial,
you can't attach to strace's tracees. Recently I spent 2 days trying to
understand why strace -f hangs. I was able to attach to strace, but
I wasn't able to see what its tracees do.
And, it was not possible to even trace strace until it hangs, with
ptrace the tracee (strace) must stop to report the event and this
shadowed the race.
Oleg.
next prev parent reply other threads:[~2010-01-26 21:54 UTC|newest]
Thread overview: 125+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100119211646.GF16096@redhat.com>
2010-01-20 0:12 ` linux-next: add utrace tree Stephen Rothwell
2010-01-20 5:49 ` Ingo Molnar
2010-01-20 6:15 ` Ananth N Mavinakayanahalli
2010-01-20 6:28 ` Ingo Molnar
2010-01-20 6:40 ` Ananth N Mavinakayanahalli
2010-01-20 10:43 ` Frederic Weisbecker
2010-01-20 6:59 ` Stephen Rothwell
2010-01-20 13:24 ` Frank Ch. Eigler
2010-01-20 7:29 ` Ingo Molnar
2010-01-20 14:38 ` Stephen Rothwell
2010-01-21 1:22 ` Roland McGrath
2010-01-22 0:17 ` Stephen Rothwell
2010-01-22 0:30 ` Andrew Morton
2010-01-22 0:31 ` Andrew Morton
2010-01-22 0:51 ` Frank Ch. Eigler
2010-01-22 1:05 ` Andrew Morton
2010-01-22 1:25 ` Frank Ch. Eigler
2010-01-22 1:32 ` Linus Torvalds
2010-01-22 2:22 ` Frank Ch. Eigler
2010-01-22 2:35 ` Linus Torvalds
2010-01-22 20:51 ` Oleg Nesterov
2010-01-23 6:04 ` Ingo Molnar
2010-01-23 12:03 ` Frank Ch. Eigler
2010-01-24 16:36 ` Thomas Gleixner
2010-01-22 1:28 ` Linus Torvalds
2010-01-22 5:21 ` Ananth N Mavinakayanahalli
2010-01-22 13:43 ` Valdis.Kletnieks
2010-01-22 19:39 ` Oleg Nesterov
2010-01-26 13:58 ` Pavel Machek
2010-01-22 18:28 ` Oleg Nesterov
2010-01-22 20:01 ` Frank Ch. Eigler
2010-01-22 20:16 ` Peter Zijlstra
2010-01-22 21:44 ` Frank Ch. Eigler
2010-01-22 21:59 ` Linus Torvalds
2010-01-22 22:13 ` Frank Ch. Eigler
2010-01-23 0:11 ` Linus Torvalds
2010-01-23 0:22 ` Linus Torvalds
2010-01-23 6:20 ` Kyle Moffett
2010-01-23 11:01 ` Alan Cox
2010-01-23 11:51 ` Frank Ch. Eigler
2010-01-23 15:57 ` Arnaldo Carvalho de Melo
2010-01-23 11:23 ` Ingo Molnar
2010-01-23 11:47 ` Frank Ch. Eigler
2010-01-23 19:48 ` tytso
2010-01-24 18:01 ` Frank Ch. Eigler
2010-01-25 1:42 ` Kyle Moffett
2010-01-25 4:55 ` tytso
2010-01-25 16:52 ` Linus Torvalds
2010-01-25 17:02 ` Frank Ch. Eigler
2010-01-25 17:36 ` Linus Torvalds
2010-01-25 17:45 ` Linus Torvalds
2010-01-25 17:54 ` Steven Rostedt
2010-01-25 18:03 ` Alan Cox
2010-01-25 18:12 ` Linus Torvalds
2010-01-25 18:30 ` Steven Rostedt
2010-01-25 18:45 ` Thomas Gleixner
2010-01-25 20:34 ` Ingo Molnar
2010-01-25 20:30 ` Mark Wielaard
2010-01-25 20:42 ` Linus Torvalds
2010-01-26 0:02 ` Renzo Davoli
2010-01-26 0:07 ` Linus Torvalds
2010-01-26 16:08 ` Johannes Stezenbach
2010-01-26 16:28 ` Linus Torvalds
2010-01-26 16:34 ` Christoph Hellwig
2010-01-28 23:53 ` Benjamin Herrenschmidt
2010-01-29 0:21 ` Linus Torvalds
2010-01-25 4:59 ` Ananth N Mavinakayanahalli
2010-01-25 10:13 ` Peter Zijlstra
2010-01-24 5:04 ` Linus Torvalds
2010-01-24 10:25 ` tytso
2010-01-24 13:20 ` Frank Ch. Eigler
2010-01-25 21:05 ` Tom Tromey
2010-01-25 21:41 ` Linus Torvalds
2010-01-26 14:21 ` Ananth N Mavinakayanahalli
2010-01-26 23:20 ` Tom Tromey
2010-01-26 23:37 ` Linus Torvalds
2010-01-27 6:52 ` Peter Zijlstra
2010-01-27 8:54 ` Ingo Molnar
2010-01-28 1:52 ` Jim Keniston
2010-01-28 8:55 ` Ingo Molnar
2010-01-29 0:59 ` Jim Keniston
2010-01-29 7:39 ` Ingo Molnar
2010-01-29 7:52 ` Ananth N Mavinakayanahalli
2010-01-29 7:55 ` Ananth N Mavinakayanahalli
2010-01-29 9:16 ` Ingo Molnar
2010-01-29 9:11 ` Ingo Molnar
2010-01-29 9:31 ` Ananth N Mavinakayanahalli
2010-01-29 9:51 ` Ingo Molnar
2010-01-29 18:13 ` Frank Ch. Eigler
2010-01-29 4:55 ` Ananth N Mavinakayanahalli
2010-01-29 7:42 ` Ingo Molnar
2010-01-30 17:49 ` Steven Rostedt
2010-01-30 17:59 ` Linus Torvalds
2010-02-02 6:47 ` Masami Hiramatsu
2010-01-27 10:43 ` Linus Torvalds
2010-01-27 10:55 ` Peter Zijlstra
2010-01-27 10:58 ` Peter Zijlstra
2010-01-27 11:04 ` Linus Torvalds
2010-01-27 16:01 ` Frederic Weisbecker
2010-01-27 11:05 ` Ananth N Mavinakayanahalli
2010-01-27 11:08 ` Peter Zijlstra
2010-01-27 11:20 ` Ananth N Mavinakayanahalli
2010-02-08 10:09 ` Avi Kivity
2010-01-27 11:07 ` Srikar Dronamraju
2010-01-27 13:59 ` Steven Rostedt
2010-01-27 17:42 ` H. Peter Anvin
2010-01-27 18:53 ` Steven Rostedt
2010-02-08 6:54 ` Pavel Machek
2010-02-08 9:30 ` H. Peter Anvin
2010-02-08 9:53 ` Arjan van de Ven
2010-01-27 19:18 ` H. Peter Anvin
2010-01-27 0:38 ` Frank Ch. Eigler
2010-01-26 15:00 ` Frank Ch. Eigler
2010-01-26 17:33 ` Andi Kleen
2010-01-26 18:46 ` Linus Torvalds
2010-01-26 21:02 ` Andi Kleen
2010-01-26 21:53 ` Oleg Nesterov [this message]
2010-01-26 22:03 ` Andi Kleen
2010-01-26 23:32 ` Oleg Nesterov
2010-01-26 21:30 ` Oleg Nesterov
2010-01-26 23:27 ` Tom Tromey
2010-01-23 8:05 ` Alexey Dobriyan
2010-01-22 17:45 ` Oleg Nesterov
2010-01-20 8:52 ` Peter Zijlstra
2010-01-20 13:01 ` Frank Ch. Eigler
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