From: Andi Kleen <andi@firstfloor.org>
To: Waiman Long <Waiman.Long@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Darren Hart <dvhart@linux.intel.com>,
Davidlohr Bueso <davidlohr@hp.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
linux-doc@vger.kernel.org, Jason Low <jason.low2@hp.com>,
Scott J Norton <scott.norton@hp.com>
Subject: Re: [RFC PATCH 0/5] futex: introduce an optimistic spinning futex
Date: Mon, 21 Jul 2014 09:45:55 -0700 [thread overview]
Message-ID: <871tte3bjw.fsf@tassilo.jf.intel.com> (raw)
In-Reply-To: <8761iq3bp3.fsf@tassilo.jf.intel.com> (Andi Kleen's message of "Mon, 21 Jul 2014 09:42:48 -0700")
Andi Kleen <andi@firstfloor.org> writes:
> Waiman Long <Waiman.Long@hp.com> writes:
>
>> This patch series introduces two new futex command codes to support
>> a new optimistic spinning futex for implementing an exclusive lock
>> primitive that should perform better than the same primitive using
>> the wait-wake futex in cases where the lock owner is actively working
>> instead of waiting for I/O completion.
>
> How would you distinguish those two cases automatically?
Also BTW traditionally the spinning was just done in user space.
This would be always even more efficient, because it would
even avoid the syscall entry path.
Given the glibc adaptive mutexes are not very good, but I'm sure those
could be improved.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2014-07-21 16:46 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-21 15:24 [RFC PATCH 0/5] futex: introduce an optimistic spinning futex Waiman Long
2014-07-21 15:24 ` [RFC PATCH 1/5] futex: add new exclusive lock & unlock command codes Waiman Long
2014-07-21 16:42 ` Thomas Gleixner
2014-07-22 18:22 ` Waiman Long
2014-07-22 21:00 ` Thomas Gleixner
2014-07-21 15:24 ` [RFC PATCH 2/5] futex: add optimistic spinning to FUTEX_SPIN_LOCK Waiman Long
2014-07-21 17:15 ` Davidlohr Bueso
2014-07-22 18:46 ` Waiman Long
2014-07-21 20:17 ` Jason Low
2014-07-22 19:34 ` Waiman Long
2014-07-21 15:24 ` [RFC PATCH 3/5] spinning futex: move a wakened task to spinning Waiman Long
2014-07-21 15:24 ` [RFC PATCH 4/5] spinning futex: put waiting tasks in a sorted rbtree Waiman Long
2014-07-21 15:24 ` [RFC PATCH 5/5] futex, doc: add a document on how to use the spinning futexes Waiman Long
2014-07-21 15:45 ` Randy Dunlap
2014-07-22 3:19 ` Waiman Long
2014-07-21 16:42 ` [RFC PATCH 0/5] futex: introduce an optimistic spinning futex Andi Kleen
2014-07-21 16:45 ` Andi Kleen [this message]
2014-07-21 17:20 ` Darren Hart
[not found] ` <CFF29A00.9D44A%dvhart@linux.intel.com>
2014-07-21 17:41 ` Darren Hart
2014-07-21 20:16 ` Thomas Gleixner
2014-07-21 21:27 ` Peter Zijlstra
2014-07-21 21:31 ` Andy Lutomirski
2014-07-21 21:47 ` Thomas Gleixner
2014-07-21 22:41 ` Darren Hart
2014-07-22 1:01 ` Thomas Gleixner
2014-07-22 1:34 ` Steven Rostedt
2014-07-22 2:31 ` Mike Galbraith
2014-07-22 3:06 ` Davidlohr Bueso
2014-07-22 7:47 ` Peter Zijlstra
2014-07-22 8:39 ` Thomas Gleixner
2014-07-22 8:48 ` Peter Zijlstra
2014-07-22 9:59 ` Thomas Gleixner
2014-07-22 20:25 ` Waiman Long
2014-07-22 20:52 ` Thomas Gleixner
2014-07-22 20:21 ` Waiman Long
2014-07-22 21:03 ` Thomas Gleixner
2014-07-22 0:32 ` Davidlohr Bueso
2014-07-22 7:35 ` Peter Zijlstra
2014-07-21 21:43 ` Thomas Gleixner
2014-07-21 18:24 ` Thomas Gleixner
2014-07-22 18:35 ` Waiman Long
2014-07-22 18:28 ` Waiman Long
2014-07-23 4:55 ` Mike Galbraith
2014-07-23 6:57 ` Peter Zijlstra
2014-07-23 7:25 ` Mike Galbraith
2014-07-23 7:35 ` Peter Zijlstra
2014-07-23 7:39 ` Mike Galbraith
2014-07-23 7:52 ` Peter Zijlstra
2014-07-21 21:18 ` Ingo Molnar
2014-07-21 21:41 ` Thomas Gleixner
2014-07-22 19:36 ` Waiman Long
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