From: Tejun Heo <tj@kernel.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Fleming <matt@console-pimps.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
"H. Peter Anvin" <hpa@zytor.com>,
Matt Fleming <matt.fleming@linux.intel.com>
Subject: Re: [RFC][PATCH 1/5] signals: Always place SIGCONT and SIGSTOP on 'shared_pending'
Date: Wed, 6 Apr 2011 06:09:28 -0700 [thread overview]
Message-ID: <20110406130928.GF4142@mtj.dyndns.org> (raw)
In-Reply-To: <20110406125757.GA12099@redhat.com>
Hey, guys.
On Wed, Apr 06, 2011 at 02:57:57PM +0200, Oleg Nesterov wrote:
> But even SIGSTOP should be routed properly. If the process is ptraced,
> the tracee reports SIGSTOP to the debugger first. This means that
> tkill(SIGSTOP) should be delivered to the right target.
I think the more important part is that there really isn't much point
in optimizing SIGSTOP/CONT. They inherently involve heavy,
walk-every-thread operations of putting them to sleep and reversing it
and there isn't much point in optimizing sending SIGSTOP to stopped
processes or CONT to running ones. In addition, STOP/CONT interaction
is already scary enough so I'd like to avoid adding complexities there
if at all possible.
I think it would be better to concentrate on more usual signals.
Thank you.
--
tejun
next prev parent reply other threads:[~2011-04-06 13:09 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-05 19:21 [RFC][PATCH 0/5] Improve signal delivery scalability Matt Fleming
2011-04-05 19:21 ` [RFC][PATCH 1/5] signals: Always place SIGCONT and SIGSTOP on 'shared_pending' Matt Fleming
2011-04-05 20:19 ` Oleg Nesterov
2011-04-05 20:50 ` Matt Fleming
2011-04-06 12:57 ` Oleg Nesterov
2011-04-06 13:09 ` Tejun Heo [this message]
2011-04-06 13:30 ` Matt Fleming
2011-04-06 13:15 ` Matt Fleming
2011-04-11 18:50 ` Oleg Nesterov
2011-04-11 19:24 ` Matt Fleming
2011-04-05 19:21 ` [RFC][PATCH 2/5] signals: Introduce per-thread siglock and action rwlock Matt Fleming
2011-04-13 19:42 ` Oleg Nesterov
2011-04-14 10:34 ` Matt Fleming
2011-04-14 19:00 ` Oleg Nesterov
2011-04-16 13:08 ` Matt Fleming
2011-04-18 16:45 ` Oleg Nesterov
2011-04-21 19:03 ` arch/tile/kernel/hardwall.c:do_hardwall_trap unsafe/wrong usage of ->sighand Oleg Nesterov
2011-04-22 13:04 ` Chris Metcalf
2011-04-26 20:36 ` [PATCH 0/1] tile: do_hardwall_trap: do not play with task->sighand Oleg Nesterov
2011-04-26 20:37 ` [PATCH 1/1] " Oleg Nesterov
2011-05-02 22:42 ` Chris Metcalf
2011-04-26 9:46 ` [RFC][PATCH 2/5] signals: Introduce per-thread siglock and action rwlock Matt Fleming
2011-04-05 19:21 ` [RFC][PATCH 3/5] ia64: Catch up with new sighand action spinlock Matt Fleming
2011-04-05 19:21 ` [RFC][PATCH 4/5] signals: Introduce __dequeue_private_signal helper function Matt Fleming
2011-04-05 19:21 ` [RFC][PATCH 5/5] signals: Don't hold shared siglock across signal delivery Matt Fleming
2011-04-13 20:12 ` Oleg Nesterov
2011-04-14 10:57 ` Matt Fleming
2011-04-14 19:20 ` Oleg Nesterov
2011-04-16 13:27 ` Matt Fleming
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