From: Rob Landley <rob@landley.net>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
paulmck@linux.vnet.ibm.com,
Frederic Weisbecker <fweisbec@gmail.com>,
linux-kernel@vger.kernel.org, josh@joshtriplett.org,
zhong@linux.vnet.ibm.com, khilman@linaro.org,
geoff@infradead.org, tglx@linutronix.de
Subject: Re: [PATCH] nohz1: Documentation
Date: Thu, 21 Mar 2013 23:59:50 -0500 [thread overview]
Message-ID: <1363928390.15703.57@driftwood> (raw)
In-Reply-To: <514B2B03.4030301@linux.intel.com> (from arjan@linux.intel.com on Thu Mar 21 10:45:07 2013)
On 03/21/2013 10:45:07 AM, Arjan van de Ven wrote:
> On 3/20/2013 5:27 PM, Steven Rostedt wrote:
>> I'm not sure I would recommend idle=poll either. It would certainly
>> work, but it goes to the other extreme. You think NO_HZ=n drains a
>> battery? Try idle=poll.
>
>
> do not ever use idle=poll on anything production.. really bad idea.
>
> if you temporary cannot cope with the latency, you can use the PMQOS
> system
> to limit (including going all the way to idle=poll).
> but using idle=poll completely is very nasty for the hardware.
>
> In addition we should document that idle=poll will cost you peak
> performance,
> possibly quite a bit.
Where should that be documented?
> the same is true for the kernel paramter to some extend; it's there
> to work around
> broken bioses/hardware/etc; if you have a latency/runtime
> requirement, it's much better
> to use PMQOS for this from userspace.
I googled and found
http://elinux.org/images/f/f9/Elc2008_pm_qos_slides.pdf
Rob
next prev parent reply other threads:[~2013-03-22 4:59 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-18 16:29 [PATCH] nohz1: Documentation Paul E. McKenney
2013-03-18 18:13 ` Rob Landley
2013-03-18 18:46 ` Frederic Weisbecker
2013-03-18 19:59 ` Rob Landley
2013-03-18 20:48 ` Frederic Weisbecker
2013-03-18 22:25 ` Paul E. McKenney
2013-03-20 23:32 ` Steven Rostedt
2013-03-20 23:55 ` Paul E. McKenney
2013-03-21 0:27 ` Steven Rostedt
2013-03-21 2:22 ` Paul E. McKenney
2013-03-21 10:16 ` Borislav Petkov
2013-03-21 15:18 ` Paul E. McKenney
2013-03-21 16:00 ` Borislav Petkov
2013-03-21 15:45 ` Arjan van de Ven
2013-03-21 17:18 ` Paul E. McKenney
2013-03-21 17:41 ` Arjan van de Ven
2013-03-21 18:02 ` Paul E. McKenney
2013-03-22 18:37 ` Kevin Hilman
2013-03-22 19:25 ` Paul E. McKenney
2013-03-22 4:59 ` Rob Landley [this message]
2013-03-21 18:01 ` Frederic Weisbecker
2013-03-21 18:26 ` Paul E. McKenney
2013-03-21 16:08 ` Christoph Lameter
2013-03-21 17:15 ` Paul E. McKenney
2013-03-21 18:39 ` Christoph Lameter
2013-03-21 18:58 ` Paul E. McKenney
2013-03-21 20:04 ` Christoph Lameter
2013-03-21 20:42 ` Frederic Weisbecker
2013-03-21 21:02 ` Christoph Lameter
2013-03-21 21:06 ` Frederic Weisbecker
2013-03-21 20:50 ` Paul E. McKenney
2013-03-22 14:38 ` Christoph Lameter
2013-03-22 16:28 ` Paul E. McKenney
2013-03-25 14:31 ` Christoph Lameter
2013-03-25 14:37 ` Frederic Weisbecker
2013-03-25 15:18 ` Christoph Lameter
2013-03-25 15:20 ` Frederic Weisbecker
2013-03-22 9:52 ` Mats Liljegren
2013-03-22 19:01 ` Kevin Hilman
2013-03-21 18:44 ` Steven Rostedt
2013-03-21 18:53 ` Christoph Lameter
2013-03-21 19:16 ` Steven Rostedt
2013-03-21 18:59 ` Paul E. McKenney
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=1363928390.15703.57@driftwood \
--to=rob@landley.net \
--cc=arjan@linux.intel.com \
--cc=fweisbec@gmail.com \
--cc=geoff@infradead.org \
--cc=josh@joshtriplett.org \
--cc=khilman@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--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.