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
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=51AC6625.3080000@message-id.invalid.com \
--to=stefan.seyfried@googlemail.com \
--cc=bp@alien8.de \
--cc=efault@gmx.de \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=zhong@linux.vnet.ibm.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.