From: Stefan Seyfried <stefan.seyfried@googlemail.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
Li Zhong <zhong@linux.vnet.ibm.com>,
Mike Galbraith <efault@gmx.de>
Subject: Re: [PATCH 2/8] vtime: Use consistent clocks among nohz accounting
Date: Mon, 03 Jun 2013 11:47:17 +0200 [thread overview]
Message-ID: <51AC6625.3080000@message-id.invalid.com> (raw)
In-Reply-To: <1369065716-22801-3-git-send-email-fweisbec@gmail.com>
Am 20.05.2013 18:01, schrieb Frederic Weisbecker:
> While computing the cputime delta of dynticks CPUs,
> we are mixing up clocks of differents natures:
[...]
> As a consequence, some strange behaviour with unstable tsc
> has been observed such as non progressing constant zero cputime.
> (The 'top' command showing no load).
This happens for example on my trusty ThinkPad X200s (family 6 model 23
stepping 10 Core 2 duo), seriously confusing its user (me :-).
> Fix this by only using local_clock(), or its irq safe/remote
> equivalent, in vtime code.
>
> Reported-by: Mike Galbraith <efault@gmx.de>
> Suggested-by: Mike Galbraith <efault@gmx.de>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Li Zhong <zhong@linux.vnet.ibm.com>
> Cc: Mike Galbraith <efault@gmx.de>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
FWIW:
Tested-by: Stefan Seyfried <seife+dev@b1-systems.com>
This patch fixes the 0% CPU issue on openSUSE Factory kernels for me.
Best regards,
Stefan
--
Stefan Seyfried
Linux Consultant & Developer -- GPG Key: 0x731B665B
B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537
next prev parent reply other threads:[~2013-06-03 9:58 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-20 16:01 [PATCH 0/8] nohz: Random fixes Frederic Weisbecker
2013-05-20 16:01 ` [PATCH 1/8] nohz: Warn if the machine can not perform nohz_full Frederic Weisbecker
2013-05-20 16:01 ` [PATCH 2/8] vtime: Use consistent clocks among nohz accounting Frederic Weisbecker
2013-06-03 9:47 ` Stefan Seyfried [this message]
2013-06-03 13:48 ` Steven Rostedt
2013-06-03 19:48 ` Frederic Weisbecker
2013-06-03 19:51 ` Stefan Seyfried
2013-06-03 20:12 ` Frederic Weisbecker
2013-05-20 16:01 ` [PATCH 3/8] watchdog: Boot-disable by default on full dynticks Frederic Weisbecker
2013-05-20 17:52 ` Don Zickus
2013-05-20 18:14 ` Frederic Weisbecker
2013-05-20 16:01 ` [PATCH 4/8] kvm: Move guest entry/exit APIs to context_tracking Frederic Weisbecker
2013-05-20 16:01 ` [PATCH 5/8] nohz: Fix notifier return val that enforce timekeeping Frederic Weisbecker
2013-05-20 16:01 ` [RFC PATCH 6/8] kthread: Enable parking requests from setup() and unpark() callbacks Frederic Weisbecker
2013-05-21 5:34 ` anish singh
2013-05-21 7:49 ` Srivatsa S. Bhat
2013-05-21 8:58 ` anish singh
2013-05-21 9:07 ` Srivatsa S. Bhat
2013-05-22 15:18 ` Frederic Weisbecker
2013-05-21 6:59 ` Srivatsa S. Bhat
2013-06-05 16:33 ` Frederic Weisbecker
2013-05-20 16:01 ` [RFC PATCH 7/8] watchdog: Rename confusing state variable Frederic Weisbecker
2013-05-20 17:53 ` Don Zickus
2013-05-20 16:01 ` [RFC PATCH 8/8] watchdog: Fix internal state with boot user disabled watchdog Frederic Weisbecker
2013-05-20 17:54 ` Don Zickus
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