From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Will Deacon <will.deacon@arm.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
Waiman Long <waiman.long@hp.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Alex Shi <alex.shi@linaro.org>, Andi Kleen <andi@firstfloor.org>,
Michel Lespinasse <walken@google.com>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
Matthew R Wilcox <matthew.r.wilcox@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH v6 4/5] MCS Lock: Barrier corrections
Date: Wed, 27 Nov 2013 17:58:40 +0100 [thread overview]
Message-ID: <20131127165840.GA26138@redhat.com> (raw)
In-Reply-To: <20131126192133.GF789@laptop.programming.kicks-ass.net>
On 11/26, Peter Zijlstra wrote:
>
> On Tue, Nov 26, 2013 at 11:00:50AM -0800, Linus Torvalds wrote:
>
> > IOW, where do we really care about the "unlock+lock" is a memory
> > barrier? And could we make those places explicit, and then do
> > something similar to the above to them?
>
> So I don't know :-(
>
> I do know myself and Oleg have often talked about it, and I'm fairly
> sure we must have used it at some point.
No... I can't recall any particular place which explicitely relies
on "unlock+lock => mb().
(although I know the out-of-tree example which can be ignored ;)
I can only recall that this was mentioned in the context like
"no, the lack of mb() can't explain the problem because we have
unlock+lock".
Oleg.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Will Deacon <will.deacon@arm.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
Waiman Long <waiman.long@hp.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Alex Shi <alex.shi@linaro.org>, Andi Kleen <andi@firstfloor.org>,
Michel Lespinasse <walken@google.com>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
Matthew R Wilcox <matthew.r.wilcox@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Rik van Riel <riel@redhat.com>,
Peter Hurley <peter@hurleysoftware.com>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
George Spelvin <linux@horizon.com>,
"H. Peter Anvin" <hpa@zytor.com>, Arnd Bergmann <arnd@arndb.de>,
Aswin Chandramouleeswaran <aswin@hp.com>,
Scott J Norton <scott.norton@hp.com>,
"Figo.zhang" <figo1802@gmail.com>
Subject: Re: [PATCH v6 4/5] MCS Lock: Barrier corrections
Date: Wed, 27 Nov 2013 17:58:40 +0100 [thread overview]
Message-ID: <20131127165840.GA26138@redhat.com> (raw)
In-Reply-To: <20131126192133.GF789@laptop.programming.kicks-ass.net>
On 11/26, Peter Zijlstra wrote:
>
> On Tue, Nov 26, 2013 at 11:00:50AM -0800, Linus Torvalds wrote:
>
> > IOW, where do we really care about the "unlock+lock" is a memory
> > barrier? And could we make those places explicit, and then do
> > something similar to the above to them?
>
> So I don't know :-(
>
> I do know myself and Oleg have often talked about it, and I'm fairly
> sure we must have used it at some point.
No... I can't recall any particular place which explicitely relies
on "unlock+lock => mb().
(although I know the out-of-tree example which can be ignored ;)
I can only recall that this was mentioned in the context like
"no, the lack of mb() can't explain the problem because we have
unlock+lock".
Oleg.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-11-27 16:58 UTC|newest]
Thread overview: 239+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1384885312.git.tim.c.chen@linux.intel.com>
2013-11-20 1:37 ` [PATCH v6 0/5] MCS Lock: MCS lock code cleanup and optimizations Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 10:19 ` Will Deacon
2013-11-20 10:19 ` Will Deacon
2013-11-20 12:50 ` Paul E. McKenney
2013-11-20 12:50 ` Paul E. McKenney
2013-11-20 17:00 ` Will Deacon
2013-11-20 17:00 ` Will Deacon
2013-11-20 17:14 ` Paul E. McKenney
2013-11-20 17:14 ` Paul E. McKenney
2013-11-20 17:00 ` Tim Chen
2013-11-20 17:00 ` Tim Chen
2013-11-20 17:16 ` Paul E. McKenney
2013-11-20 17:16 ` Paul E. McKenney
2013-11-20 1:37 ` [PATCH v6 1/5] MCS Lock: Restructure the MCS lock defines and locking code into its own file Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` [PATCH v6 2/5] MCS Lock: optimizations and extra comments Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` [PATCH v6 3/5] MCS Lock: Move mcs_lock/unlock function into its own file Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` [PATCH v6 4/5] MCS Lock: Barrier corrections Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 15:31 ` Paul E. McKenney
2013-11-20 15:31 ` Paul E. McKenney
2013-11-20 15:31 ` Paul E. McKenney
2013-11-20 15:46 ` Will Deacon
2013-11-20 15:46 ` Will Deacon
2013-11-20 17:14 ` Paul E. McKenney
2013-11-20 17:14 ` Paul E. McKenney
2013-11-20 18:43 ` Tim Chen
2013-11-20 18:43 ` Tim Chen
2013-11-20 19:06 ` Paul E. McKenney
2013-11-20 19:06 ` Paul E. McKenney
2013-11-20 20:36 ` Tim Chen
2013-11-20 20:36 ` Tim Chen
2013-11-20 21:44 ` Paul E. McKenney
2013-11-20 21:44 ` Paul E. McKenney
2013-11-20 23:51 ` Tim Chen
2013-11-20 23:51 ` Tim Chen
2013-11-21 4:53 ` Paul E. McKenney
2013-11-21 4:53 ` Paul E. McKenney
2013-11-21 10:17 ` Will Deacon
2013-11-21 10:17 ` Will Deacon
2013-11-21 13:16 ` Paul E. McKenney
2013-11-21 13:16 ` Paul E. McKenney
2013-11-21 10:45 ` Peter Zijlstra
2013-11-21 10:45 ` Peter Zijlstra
2013-11-21 13:18 ` Paul E. McKenney
2013-11-21 13:18 ` Paul E. McKenney
2013-11-21 22:27 ` Linus Torvalds
2013-11-21 22:27 ` Linus Torvalds
2013-11-21 22:52 ` Paul E. McKenney
2013-11-21 22:52 ` Paul E. McKenney
2013-11-22 0:09 ` Linus Torvalds
2013-11-22 0:09 ` Linus Torvalds
2013-11-22 4:08 ` Paul E. McKenney
2013-11-22 4:08 ` Paul E. McKenney
2013-11-22 4:25 ` Linus Torvalds
2013-11-22 4:25 ` Linus Torvalds
2013-11-22 6:23 ` Paul E. McKenney
2013-11-22 6:23 ` Paul E. McKenney
2013-11-22 15:16 ` Ingo Molnar
2013-11-22 15:16 ` Ingo Molnar
2013-11-22 18:49 ` Paul E. McKenney
2013-11-22 18:49 ` Paul E. McKenney
2013-11-22 19:06 ` Linus Torvalds
2013-11-22 19:06 ` Linus Torvalds
2013-11-22 20:06 ` Paul E. McKenney
2013-11-22 20:06 ` Paul E. McKenney
2013-11-22 20:09 ` Linus Torvalds
2013-11-22 20:09 ` Linus Torvalds
2013-11-22 20:37 ` Paul E. McKenney
2013-11-22 20:37 ` Paul E. McKenney
2013-11-22 21:01 ` Linus Torvalds
2013-11-22 21:01 ` Linus Torvalds
2013-11-22 21:52 ` Paul E. McKenney
2013-11-22 21:52 ` Paul E. McKenney
2013-11-22 22:19 ` Linus Torvalds
2013-11-22 22:19 ` Linus Torvalds
2013-11-23 0:25 ` Paul E. McKenney
2013-11-23 0:25 ` Paul E. McKenney
2013-11-23 0:42 ` Linus Torvalds
2013-11-23 0:42 ` Linus Torvalds
2013-11-23 1:36 ` Paul E. McKenney
2013-11-23 1:36 ` Paul E. McKenney
2013-11-23 2:11 ` Linus Torvalds
2013-11-23 2:11 ` Linus Torvalds
2013-11-23 4:05 ` Paul E. McKenney
2013-11-23 4:05 ` Paul E. McKenney
2013-11-23 11:24 ` Ingo Molnar
2013-11-23 11:24 ` Ingo Molnar
2013-11-23 17:06 ` Paul E. McKenney
2013-11-23 17:06 ` Paul E. McKenney
2013-11-26 12:02 ` Ingo Molnar
2013-11-26 12:02 ` Ingo Molnar
2013-11-26 19:28 ` Paul E. McKenney
2013-11-26 19:28 ` Paul E. McKenney
2013-11-23 20:21 ` Linus Torvalds
2013-11-23 20:21 ` Linus Torvalds
2013-11-23 20:39 ` Linus Torvalds
2013-11-23 20:39 ` Linus Torvalds
2013-11-25 12:09 ` Peter Zijlstra
2013-11-25 12:09 ` Peter Zijlstra
2013-11-25 17:18 ` Will Deacon
2013-11-25 17:18 ` Will Deacon
2013-11-25 17:56 ` Paul E. McKenney
2013-11-25 17:56 ` Paul E. McKenney
2013-11-25 17:54 ` Paul E. McKenney
2013-11-25 17:54 ` Paul E. McKenney
2013-11-23 21:29 ` Peter Zijlstra
2013-11-23 21:29 ` Peter Zijlstra
2013-11-23 22:24 ` Linus Torvalds
2013-11-23 22:24 ` Linus Torvalds
2013-11-25 17:53 ` Paul E. McKenney
2013-11-25 17:53 ` Paul E. McKenney
2013-11-25 18:21 ` Peter Zijlstra
2013-11-25 18:21 ` Peter Zijlstra
2013-11-21 11:03 ` Peter Zijlstra
2013-11-21 11:03 ` Peter Zijlstra
2013-11-21 12:56 ` Peter Zijlstra
2013-11-21 12:56 ` Peter Zijlstra
2013-11-21 13:20 ` Paul E. McKenney
2013-11-21 13:20 ` Paul E. McKenney
2013-11-21 17:25 ` Paul E. McKenney
2013-11-21 17:25 ` Paul E. McKenney
2013-11-21 21:52 ` Peter Zijlstra
2013-11-21 21:52 ` Peter Zijlstra
2013-11-21 22:18 ` Paul E. McKenney
2013-11-21 22:18 ` Paul E. McKenney
2013-11-22 15:58 ` Peter Zijlstra
2013-11-22 15:58 ` Peter Zijlstra
2013-11-22 18:26 ` Paul E. McKenney
2013-11-22 18:26 ` Paul E. McKenney
2013-11-22 18:51 ` Peter Zijlstra
2013-11-22 18:51 ` Peter Zijlstra
2013-11-22 18:59 ` Paul E. McKenney
2013-11-22 18:59 ` Paul E. McKenney
2013-11-25 17:35 ` Peter Zijlstra
2013-11-25 17:35 ` Peter Zijlstra
2013-11-25 18:02 ` Paul E. McKenney
2013-11-25 18:02 ` Paul E. McKenney
2013-11-25 18:24 ` Peter Zijlstra
2013-11-25 18:24 ` Peter Zijlstra
2013-11-25 18:34 ` Tim Chen
2013-11-25 18:34 ` Tim Chen
2013-11-25 18:27 ` Peter Zijlstra
2013-11-25 18:27 ` Peter Zijlstra
2013-11-25 23:52 ` Paul E. McKenney
2013-11-25 23:52 ` Paul E. McKenney
2013-11-26 9:59 ` Peter Zijlstra
2013-11-26 9:59 ` Peter Zijlstra
2013-11-26 17:11 ` Paul E. McKenney
2013-11-26 17:11 ` Paul E. McKenney
2013-11-26 17:18 ` Peter Zijlstra
2013-11-26 17:18 ` Peter Zijlstra
2013-11-26 19:00 ` Linus Torvalds
2013-11-26 19:00 ` Linus Torvalds
2013-11-26 19:20 ` Paul E. McKenney
2013-11-26 19:20 ` Paul E. McKenney
2013-11-26 19:32 ` Linus Torvalds
2013-11-26 19:32 ` Linus Torvalds
2013-11-26 22:51 ` Paul E. McKenney
2013-11-26 22:51 ` Paul E. McKenney
2013-11-26 23:58 ` Linus Torvalds
2013-11-26 23:58 ` Linus Torvalds
2013-11-27 0:21 ` Thomas Gleixner
2013-11-27 0:21 ` Thomas Gleixner
2013-11-27 0:39 ` Paul E. McKenney
2013-11-27 0:39 ` Paul E. McKenney
2013-11-27 1:05 ` Linus Torvalds
2013-11-27 1:05 ` Linus Torvalds
2013-11-27 1:31 ` Paul E. McKenney
2013-11-27 1:31 ` Paul E. McKenney
2013-11-27 10:16 ` Will Deacon
2013-11-27 10:16 ` Will Deacon
2013-11-27 17:11 ` Paul E. McKenney
2013-11-27 17:11 ` Paul E. McKenney
2013-11-28 11:40 ` Will Deacon
2013-11-28 11:40 ` Will Deacon
2013-11-28 17:38 ` Paul E. McKenney
2013-11-28 17:38 ` Paul E. McKenney
2013-11-28 18:03 ` Will Deacon
2013-11-28 18:03 ` Will Deacon
2013-11-28 18:27 ` Paul E. McKenney
2013-11-28 18:27 ` Paul E. McKenney
2013-11-28 18:53 ` Will Deacon
2013-11-28 18:53 ` Will Deacon
2013-11-28 19:50 ` Paul E. McKenney
2013-11-28 19:50 ` Paul E. McKenney
2013-11-29 16:17 ` Will Deacon
2013-11-29 16:17 ` Will Deacon
2013-11-29 16:44 ` Linus Torvalds
2013-11-29 16:44 ` Linus Torvalds
2013-11-29 18:18 ` Will Deacon
2013-11-29 18:18 ` Will Deacon
2013-11-30 17:38 ` Paul E. McKenney
2013-11-30 17:38 ` Paul E. McKenney
2013-11-26 19:21 ` Peter Zijlstra
2013-11-26 19:21 ` Peter Zijlstra
2013-11-27 16:58 ` Oleg Nesterov [this message]
2013-11-27 16:58 ` Oleg Nesterov
2013-11-26 23:08 ` Benjamin Herrenschmidt
2013-11-26 23:08 ` Benjamin Herrenschmidt
2013-11-25 23:55 ` H. Peter Anvin
2013-11-25 23:55 ` H. Peter Anvin
2013-11-26 3:16 ` Paul E. McKenney
2013-11-26 3:16 ` Paul E. McKenney
2013-11-27 0:46 ` H. Peter Anvin
2013-11-27 0:46 ` H. Peter Anvin
2013-11-27 1:07 ` Linus Torvalds
2013-11-27 1:07 ` Linus Torvalds
2013-11-27 1:27 ` Paul E. McKenney
2013-11-27 1:27 ` Paul E. McKenney
2013-11-27 2:59 ` H. Peter Anvin
2013-11-27 2:59 ` H. Peter Anvin
2013-11-25 18:52 ` H. Peter Anvin
2013-11-25 18:52 ` H. Peter Anvin
2013-11-25 22:58 ` Tim Chen
2013-11-25 22:58 ` Tim Chen
2013-11-25 23:28 ` H. Peter Anvin
2013-11-25 23:28 ` H. Peter Anvin
2013-11-25 23:51 ` Paul E. McKenney
2013-11-25 23:51 ` Paul E. McKenney
2013-11-25 23:36 ` Paul E. McKenney
2013-11-25 23:36 ` Paul E. McKenney
2013-12-04 21:26 ` Andi Kleen
2013-12-04 21:26 ` Andi Kleen
2013-12-04 22:07 ` Paul E. McKenney
2013-12-04 22:07 ` Paul E. McKenney
2013-11-21 13:19 ` Paul E. McKenney
2013-11-21 13:19 ` Paul E. McKenney
2013-11-20 1:37 ` [PATCH v6 5/5] MCS Lock: Allows for architecture specific mcs lock and unlock Tim Chen
2013-11-20 1:37 ` Tim Chen
2013-11-20 1:37 ` Tim Chen
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=20131127165840.GA26138@redhat.com \
--to=oleg@redhat.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alex.shi@linaro.org \
--cc=andi@firstfloor.org \
--cc=dave.hansen@intel.com \
--cc=davidlohr.bueso@hp.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=matthew.r.wilcox@intel.com \
--cc=mingo@elte.hu \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
--cc=waiman.long@hp.com \
--cc=walken@google.com \
--cc=will.deacon@arm.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.