linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Christoph Lameter <cl@linux.com>,
	Hakan Akkan <hakanakkan@gmail.com>,
	Kevin Hilman <khilman@linaro.org>,
	Li Zhong <zhong@linux.vnet.ibm.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [GIT PULL] nohz: Bunch of fixes
Date: Fri,  3 May 2013 18:47:54 +0200	[thread overview]
Message-ID: <1367599676-2049-1-git-send-email-fweisbec@gmail.com> (raw)

Ingo,

Please pull the timers/nohz-hz1 branch that can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	timers/nohz-hz1

HEAD: a7f4d69bb1d5e1f573b680355a2ad51566338887

It fixes a Kconfig dependency issue and forces a minimum of 1 tick every seconds
to keep handling the scheduler_tick() duties, even at a very low granularity. This
is a workaround until we can handle all these duties through on-demand driven
solutions rather than using periodic events, as per your suggestion.

I just noted two things:

* update_cpu_load_active() seem to rely on the fixed periodic tick at the
  HZ rate. There is certainly something to tweak there to make it really correct
  with dynamick ticks. I have the feeling that modifying pending_updates won't work
  as it seems to decay assuming the time to catch up was idle.

* I'll probably have to disable CONFIG_CFS_BANDWIDTH when full dynticks
  is enabled. First of all it modifies rq->nr_running without using inc/dec_nr_running
  standard API, which is required for full dynticks. And second, I need to triple
  check it's safe to use with 1 tick per second.

Ah and please note the merge commit (c032862fba51a3ca504752d3a25186b324c5ce83)
that was needed to get latest RCU and sched updates for the Kconfig fix.

Thanks,
	Frederic
---

Frederic Weisbecker (2):
      rcu: Fix full dynticks' dependency on wide RCU nocb mode
      sched: Keep at least 1 tick per second for active dynticks tasks


 include/linux/sched.h    |    1 +
 init/Kconfig             |    4 ++--
 kernel/sched/core.c      |   30 ++++++++++++++++++++++++++++++
 kernel/sched/idle_task.c |    1 +
 kernel/sched/sched.h     |   10 ++++++++++
 kernel/time/Kconfig      |    1 -
 kernel/time/tick-sched.c |    7 +++++++
 7 files changed, 51 insertions(+), 3 deletions(-)

             reply	other threads:[~2013-05-03 16:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-03 16:47 Frederic Weisbecker [this message]
2013-05-03 16:47 ` [PATCH 1/2] rcu: Fix full dynticks' dependency on wide RCU nocb mode Frederic Weisbecker
2013-05-03 16:58   ` Paul E. McKenney
2013-05-04  6:37     ` Frederic Weisbecker
2013-05-03 16:47 ` [PATCH 2/2] sched: Keep at least 1 tick per second for active dynticks tasks Frederic Weisbecker
2013-05-04  6:41 ` [GIT PULL] nohz: Bunch of fixes Ingo Molnar

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=1367599676-2049-1-git-send-email-fweisbec@gmail.com \
    --to=fweisbec@gmail.com \
    --cc=cl@linux.com \
    --cc=hakanakkan@gmail.com \
    --cc=khilman@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=paul.gortmaker@windriver.com \
    --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 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).