From: Arjan van de Ven <arjan@linux.intel.com>
To: paulmck@linux.vnet.ibm.com
Cc: Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
linux-kernel@vger.kernel.org, mingo@elte.hu,
laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de,
rostedt@goodmis.org, Valdis.Kletnieks@vt.edu,
dhowells@redhat.com, edumazet@google.com, darren@dvhart.com,
fweisbec@gmail.com, sbw@mit.edu,
Kevin Hilman <khilman@linaro.org>,
Christoph Lameter <cl@linux.com>
Subject: Re: [PATCH documentation 1/2] nohz1: Add documentation.
Date: Fri, 12 Apr 2013 10:56:35 -0700 [thread overview]
Message-ID: <51684AD3.7090305@linux.intel.com> (raw)
In-Reply-To: <20130412175419.GG29861@linux.vnet.ibm.com>
> ------------------------------------------------------------------------
>
> 1. It increases the number of instructions executed on the path
> to and from the idle loop.
>
> 2. On many architectures, dyntick-idle mode also increases the
> number of times that clocks must be reprogrammed, and this
> reprogramming can be quite expensive.
it's really that we're no longer using periodic clocks, but only one-shot clocks only.
(which then leads to having to program them every time)
but arguably, that's because of HRTIMERS more than NOHZ
(e.g. I bet we still turn off periodic even for nohz as long as hrtimers are enabled)
next prev parent reply other threads:[~2013-04-12 17:56 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-11 16:05 [PATCH documentation 0/2] OS-jitter documentation Paul E. McKenney
2013-04-11 16:05 ` [PATCH documentation 1/2] nohz1: Add documentation Paul E. McKenney
2013-04-11 16:05 ` [PATCH documentation 2/2] kthread: Document ways of reducing OS jitter due to per-CPU kthreads Paul E. McKenney
2013-04-11 17:18 ` Randy Dunlap
2013-04-11 18:40 ` Paul E. McKenney
2013-04-11 20:09 ` Randy Dunlap
2013-04-11 21:00 ` Paul E. McKenney
2013-04-11 16:48 ` [PATCH documentation 1/2] nohz1: Add documentation Randy Dunlap
2013-04-11 17:09 ` Paul E. McKenney
2013-04-11 17:14 ` Arjan van de Ven
2013-04-11 18:27 ` Paul E. McKenney
2013-04-11 18:43 ` Dipankar Sarma
2013-04-11 19:14 ` Paul E. McKenney
2013-04-11 18:25 ` Borislav Petkov
2013-04-11 19:13 ` Paul E. McKenney
2013-04-11 20:19 ` Borislav Petkov
2013-04-11 21:01 ` Paul E. McKenney
2013-04-12 8:05 ` Peter Zijlstra
2013-04-12 17:54 ` Paul E. McKenney
2013-04-12 17:56 ` Arjan van de Ven [this message]
2013-04-12 20:39 ` Paul E. McKenney
2013-04-15 16:00 ` Christoph Lameter
2013-04-15 16:41 ` Arjan van de Ven
2013-04-15 16:53 ` Christoph Lameter
2013-04-15 17:21 ` Arjan van de Ven
2013-04-19 21:01 ` Kevin Hilman
2013-04-19 21:47 ` Paul E. McKenney
2013-04-27 13:26 ` Frederic Weisbecker
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=51684AD3.7090305@linux.intel.com \
--to=arjan@linux.intel.com \
--cc=Valdis.Kletnieks@vt.edu \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=cl@linux.com \
--cc=darren@dvhart.com \
--cc=dhowells@redhat.com \
--cc=dipankar@in.ibm.com \
--cc=edumazet@google.com \
--cc=fweisbec@gmail.com \
--cc=josh@joshtriplett.org \
--cc=khilman@linaro.org \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@polymtl.ca \
--cc=mingo@elte.hu \
--cc=niv@us.ibm.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=sbw@mit.edu \
--cc=tglx@linutronix.de \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox