From: Darren Hart <dvhart@linux.intel.com>
To: George Spelvin <linux@horizon.com>
Cc: david@rgmadvisors.com, kyle@moffetthome.net, luto@mit.edu,
linux-kernel@vger.kernel.org
Subject: Re: Change in functionality of futex() system call.
Date: Wed, 08 Jun 2011 20:02:30 -0700 [thread overview]
Message-ID: <4DF037C6.4000507@linux.intel.com> (raw)
In-Reply-To: <20110609004435.14550.qmail@science.horizon.com>
On 06/08/2011 05:44 PM, George Spelvin wrote:
> I'm not sure if it's best, but the risk of RO waiters interfering could
> be solved by giving them a lower prioirty for wakeup and always waking
> RW-mapped waiters first.
This strikes me as bending over backwards and jumping through hoops
inside the kernel to avoid having to do proper permissions management in
userspace.
> In most cases, there would only be one type of waiter, so this would
> have no effect, but if there were, a RO-mapped reader couldn't "steal"
> wakeup from someone who had it RW-mapped.
>
> It might conflict with a fairness goal, but it does solve the problem
> without any extension to the API.
--
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel
next prev parent reply other threads:[~2011-06-09 3:02 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-09 0:44 Change in functionality of futex() system call George Spelvin
2011-06-09 3:02 ` Darren Hart [this message]
2011-06-09 3:38 ` Andrew Lutomirski
2011-06-09 3:54 ` Eric Dumazet
2011-06-09 4:10 ` Andrew Lutomirski
2011-06-09 5:11 ` Eric Dumazet
2011-06-09 12:12 ` Andrew Lutomirski
2011-06-09 4:43 ` George Spelvin
2011-06-09 5:25 ` Eric Dumazet
2011-06-09 4:44 ` Kyle Moffett
-- strict thread matches above, loose matches on Subject: below --
2011-06-06 14:28 David Oliver
2011-06-06 15:23 ` Eric Dumazet
2011-06-06 15:56 ` Shawn Bohrer
2011-06-06 16:11 ` Peter Zijlstra
2011-06-06 16:16 ` Peter Zijlstra
2011-06-06 16:22 ` Eric Dumazet
2011-06-06 16:29 ` Peter Zijlstra
2011-06-06 16:42 ` Eric Dumazet
2011-06-06 17:05 ` Peter Zijlstra
2011-06-06 17:11 ` Eric Dumazet
2011-06-06 17:27 ` Steven Rostedt
2011-06-06 17:56 ` Darren Hart
2011-06-06 18:23 ` Peter Zijlstra
2011-06-06 18:27 ` Eric Dumazet
2011-06-25 0:00 ` Darren Hart
2011-06-27 16:48 ` Shawn Bohrer
2011-06-06 17:53 ` Darren Hart
2011-06-06 18:11 ` Eric Dumazet
2011-06-07 3:13 ` Darren Hart
2011-06-07 3:49 ` Eric Dumazet
2011-06-07 14:44 ` Andy Lutomirski
2011-06-07 15:56 ` Darren Hart
2011-06-07 15:58 ` Eric Dumazet
2011-06-07 18:43 ` Andrew Lutomirski
2011-06-07 19:01 ` Darren Hart
2011-06-07 19:04 ` Andrew Lutomirski
2011-06-07 19:06 ` Eric Dumazet
2011-06-07 19:10 ` David Oliver
2011-06-07 19:19 ` Andrew Lutomirski
2011-06-07 19:33 ` David Oliver
2011-06-07 19:53 ` Andrew Lutomirski
2011-06-07 20:04 ` David Oliver
2011-06-07 20:12 ` Andrew Lutomirski
2011-06-07 22:26 ` Kyle Moffett
2011-06-08 15:20 ` David Oliver
2011-06-08 15:21 ` Andrew Lutomirski
2011-06-08 16:21 ` Darren Hart
2011-06-09 11:37 ` KOSAKI Motohiro
2011-06-09 12:05 ` Peter Zijlstra
2011-06-09 17:58 ` Peter Zijlstra
2011-06-10 3:30 ` KOSAKI Motohiro
2011-06-10 3:26 ` KOSAKI Motohiro
2011-06-07 18:30 ` Joel Becker
2011-06-09 12:05 ` Peter Zijlstra
2011-06-10 12:10 ` KOSAKI Motohiro
2011-06-10 17:29 ` Darren Hart
2011-06-13 2:11 ` KOSAKI Motohiro
2011-06-13 15:50 ` Darren Hart
2011-06-15 18:50 ` Shawn Bohrer
2011-06-15 18:54 ` Darren Hart
2011-06-17 13:40 ` Shawn Bohrer
2011-06-23 3:23 ` KOSAKI Motohiro
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