public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: paulmck@linux.vnet.ibm.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 19:27:21 +0200	[thread overview]
Message-ID: <1400174841.18229.6.camel@marge.simpson.net> (raw)
In-Reply-To: <20140515144553.GZ4570@linux.vnet.ibm.com>

On Thu, 2014-05-15 at 07:45 -0700, Paul E. McKenney wrote: 
> 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...

RCU signal was swamped by accounting.

-Mike


  reply	other threads:[~2014-05-15 17:27 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
2014-05-15 17:27       ` Mike Galbraith [this message]
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=1400174841.18229.6.camel@marge.simpson.net \
    --to=umgwanakikbuti@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=paul.gortmaker@windriver.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --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