From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Mike Galbraith <bitbucket@online.de>,
Borislav Petkov <bp@alien8.de>, Len Brown <lenb@kernel.org>,
Linux PM list <linux-pm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Jeremy Eder <jeder@redhat.com>,
x86@kernel.org
Subject: Re: 50 Watt idle power regression bisected to Linux-3.10
Date: Wed, 11 Dec 2013 18:48:27 +0100 [thread overview]
Message-ID: <20131211174827.GB12431@gmail.com> (raw)
In-Reply-To: <20131211164442.GC2480@laptop.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Dec 11, 2013 at 04:09:11PM +0100, Ingo Molnar wrote:
> >
> > * Thomas Gleixner <tglx@linutronix.de> wrote:
> >
> > > On Wed, 11 Dec 2013, Ingo Molnar wrote:
> > > >
> > > > Another thing that is required I think is to issue a write barrier
> > > > before CLFLUSH instruction. By my (possibly incorrect ...) reading of
> > > > the documentation CLFLUSH does not appear to be ordered (at all), so
> > > > it might execute before the modification to the affected memory?
> > >
> > > We already have a write barrier in the code which modifies
> > > current_thread_info()->flags.
> >
> > Which code is that, could you please cite it? (I tried finding it but
> > my grep-fu failed me.)
>
> current_set_polling_and_test().
Thx, those variants have the right barrier indeed.
Thanks,
Ingo
next prev parent reply other threads:[~2013-12-11 17:48 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-07 8:00 50 Watt idle power regression bisected to Linux-3.10 Len Brown
2013-12-07 8:39 ` Mike Galbraith
2013-12-07 16:01 ` Len Brown
2013-12-07 16:45 ` Len Brown
2013-12-07 19:17 ` Mike Galbraith
2013-12-10 11:41 ` Ingo Molnar
2013-12-07 12:54 ` Thomas Gleixner
2013-12-08 4:57 ` Mike Galbraith
2013-12-08 20:40 ` Len Brown
2013-12-09 3:16 ` Mike Galbraith
2013-12-10 5:17 ` Mike Galbraith
2013-12-10 11:45 ` Ingo Molnar
2013-12-10 14:29 ` Thomas Gleixner
2013-12-10 15:06 ` Ingo Molnar
2013-12-11 2:05 ` Thomas Gleixner
2013-12-11 3:21 ` Mike Galbraith
2013-12-11 11:28 ` Thomas Gleixner
2013-12-11 11:38 ` Borislav Petkov
2013-12-11 11:52 ` Peter Zijlstra
2013-12-11 12:29 ` Mike Galbraith
2013-12-11 12:43 ` Peter Zijlstra
2013-12-11 13:10 ` Mike Galbraith
2013-12-11 13:40 ` Borislav Petkov
2013-12-11 14:56 ` Ingo Molnar
2013-12-11 16:02 ` Borislav Petkov
2013-12-11 16:43 ` Peter Zijlstra
2013-12-11 17:50 ` Ingo Molnar
2013-12-11 23:08 ` H. Peter Anvin
2013-12-11 23:14 ` Borislav Petkov
2013-12-12 0:52 ` H. Peter Anvin
2013-12-12 4:25 ` Mike Galbraith
2013-12-12 4:49 ` H. Peter Anvin
2013-12-12 4:59 ` Mike Galbraith
2013-12-12 5:37 ` Mike Galbraith
2013-12-12 5:45 ` H. Peter Anvin
2013-12-12 5:57 ` Mike Galbraith
2013-12-12 6:05 ` Mike Galbraith
2013-12-12 7:57 ` H. Peter Anvin
2013-12-12 8:51 ` Peter Zijlstra
2013-12-12 13:28 ` Ingo Molnar
2013-12-12 15:06 ` H. Peter Anvin
2013-12-12 15:51 ` Peter Zijlstra
2013-12-11 14:42 ` Ingo Molnar
2013-12-11 15:02 ` Thomas Gleixner
2013-12-11 15:09 ` Ingo Molnar
2013-12-11 16:44 ` Peter Zijlstra
2013-12-11 17:48 ` Ingo Molnar [this message]
2013-12-11 16:44 ` Peter Zijlstra
2013-12-11 17:47 ` Ingo Molnar
2013-12-11 21:43 ` Len Brown
2013-12-11 22:22 ` Thomas Gleixner
2013-12-18 21:44 ` [PATCH] x86 idle: repair large-server 50-watt idle-power regression Len Brown
2013-12-18 21:44 ` Len Brown
2013-12-19 12:22 ` Ingo Molnar
2013-12-19 14:40 ` H. Peter Anvin
2013-12-19 15:45 ` Borislav Petkov
2013-12-19 15:55 ` H. Peter Anvin
2013-12-19 16:02 ` Ingo Molnar
2013-12-19 16:09 ` H. Peter Anvin
2013-12-19 16:13 ` H. Peter Anvin
2013-12-19 16:21 ` Peter Zijlstra
2013-12-19 16:50 ` H. Peter Anvin
2013-12-19 17:07 ` Ingo Molnar
2013-12-19 17:25 ` Peter Zijlstra
2013-12-19 17:36 ` Peter Zijlstra
2013-12-19 18:05 ` H. Peter Anvin
2013-12-19 18:14 ` Ingo Molnar
2013-12-19 17:50 ` Peter Zijlstra
2013-12-19 18:18 ` Ingo Molnar
2013-12-19 21:05 ` H. Peter Anvin
2013-12-19 21:17 ` Ingo Molnar
2013-12-19 18:10 ` Ingo Molnar
2013-12-19 18:09 ` H. Peter Anvin
2013-12-19 18:19 ` H. Peter Anvin
2013-12-19 18:23 ` Ingo Molnar
[not found] ` <CA+55aFzGxcML7j8CEvQPYzh0W81uVoAAVmGctMOUZ7CZ1yYd2A@mail.gmail.com>
2013-12-19 18:43 ` Ingo Molnar
2013-12-19 18:43 ` Ingo Molnar
2013-12-19 20:09 ` [tip:x86/idle] x86, idle: Use static_cpu_has() for CLFLUSH workaround, add barriers tip-bot for H. Peter Anvin
2013-12-19 20:40 ` Ingo Molnar
2013-12-19 20:46 ` Linus Torvalds
2013-12-19 21:14 ` Ingo Molnar
2013-12-19 21:25 ` Linus Torvalds
2013-12-19 21:55 ` Peter Zijlstra
2013-12-20 8:47 ` Ingo Molnar
2013-12-19 20:33 ` [tip:x86/idle] x86, idle: Add memory barriers around clflush in mwait_play_dead() tip-bot for H. Peter Anvin
2013-12-19 18:19 ` [PATCH] x86 idle: repair large-server 50-watt idle-power regression Ingo Molnar
2013-12-19 19:22 ` H. Peter Anvin
2013-12-19 19:27 ` Peter Zijlstra
2013-12-19 19:51 ` [tip:x86/urgent] x86 idle: Repair " tip-bot for Len Brown
2014-03-18 0:20 ` Davidlohr Bueso
2014-03-18 9:16 ` Peter Zijlstra
2014-03-19 2:14 ` Jason Low
2014-03-19 6:42 ` Peter Zijlstra
2014-04-08 21:43 ` Brown, Len
2014-04-09 8:18 ` Peter Zijlstra
2014-04-15 3:27 ` Davidlohr Bueso
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