From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] sched/rt: don't try to balance rt_runtime when it is futile
Date: Thu, 15 May 2014 07:45:53 -0700 [thread overview]
Message-ID: <20140515144553.GZ4570@linux.vnet.ibm.com> (raw)
In-Reply-To: <1400123931.5175.38.camel@marge.simpson.net>
On Thu, May 15, 2014 at 05:18:51AM +0200, Mike Galbraith wrote:
> On Wed, 2014-05-14 at 08:44 -0700, Paul E. McKenney wrote:
>
> > In practice, not sure how much testing CONFIG_NO_HZ_FULL=y has received
> > for -rt kernels in production environments.
>
> I took 3.14-rt out for a quick spin on my 64 core box, it didn't work at
> all with 60 cores isolated. I didn't have time to rummage, but it looks
> like there are still bugs to squash.
>
> Biggest problem with CONFIG_NO_HZ_FULL is the price tag. It just raped
> fast mover performance last time I measured.
I do have a report of the RCU grace-period kthreads (rcu_preempt,
rcu_sched, and rcu_bh) consuming excessive CPU time on large boxes,
but this is for workloads with lots of threads and context switches.
Whether relevant or not to your situation, working on it...
Thanx, Paul
next prev parent reply other threads:[~2014-05-15 14:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-14 15:08 [PATCH] sched/rt: don't try to balance rt_runtime when it is futile Paul Gortmaker
2014-05-14 15:44 ` Paul E. McKenney
2014-05-14 19:11 ` Paul Gortmaker
2014-05-14 19:27 ` Paul E. McKenney
2014-05-15 2:49 ` Mike Galbraith
2014-05-15 14:09 ` Paul Gortmaker
2014-11-27 9:17 ` Wanpeng Li
2014-11-27 15:31 ` Mike Galbraith
2014-11-27 11:36 ` Wanpeng Li
2014-05-15 3:18 ` Mike Galbraith
2014-05-15 14:45 ` Paul E. McKenney [this message]
2014-05-15 17:27 ` Mike Galbraith
2014-05-18 4:22 ` Mike Galbraith
2014-05-18 5:20 ` Paul E. McKenney
2014-05-18 8:36 ` Mike Galbraith
2014-05-18 15:58 ` Paul E. McKenney
2014-05-19 2:44 ` Mike Galbraith
2014-05-19 5:34 ` Paul E. McKenney
2014-05-20 14:53 ` Frederic Weisbecker
2014-05-20 15:53 ` Paul E. McKenney
2014-05-20 16:24 ` Frederic Weisbecker
2014-05-20 16:36 ` Peter Zijlstra
2014-05-20 17:20 ` Paul E. McKenney
2014-05-21 4:29 ` Mike Galbraith
2014-05-21 4:18 ` Mike Galbraith
2014-05-21 12:03 ` Paul E. McKenney
2014-05-21 3:52 ` Mike Galbraith
2014-05-19 10:54 ` Peter Zijlstra
2014-05-19 12:40 ` Peter Zijlstra
2014-05-22 19:40 ` Paul Gortmaker
2014-11-27 11:21 ` Wanpeng Li
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=20140515144553.GZ4570@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=paul.gortmaker@windriver.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=umgwanakikbuti@gmail.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).