From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: paulmck@linux.vnet.ibm.com
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
John Stultz <john.stultz@linaro.org>,
LKML <linux-kernel@vger.kernel.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Len Brown <len.brown@intel.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Eduardo Valentin <edubezval@gmail.com>,
Paul Turner <pjt@google.com>,
Josh Triplett <josh@joshtriplett.org>,
jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH 2/4] timer: relax tick stop in idle entry
Date: Mon, 16 Nov 2015 15:15:03 -0800 [thread overview]
Message-ID: <20151116151503.47cbd4cf@icelake> (raw)
In-Reply-To: <20151116223117.GK5184@linux.vnet.ibm.com>
On Mon, 16 Nov 2015 14:31:17 -0800
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
> > Either one works but my concern is that users may not realize the
> > intricate CONFIG_ options and how they translate into energy
> > savings. Consulted with Josh, it seems we could add a check here to
> > recognize the forced idle state and relax rcu_needs_cpu() to return
> > false even it has callbacks. Since we are blocking everybody for a
> > short time (5 ticks default). It should not impact synchronize and
> > kfree rcu.
>
> Or we could just set things up so that whatever Kconfig you are using
> to enable this state causes CONFIG_RCU_NOCB_CPU_ALL to also be
> enabled. Or that causes CONFIG_RCU_FAST_NO_HZ to also be enabled, if
> that works better for you.
That would be great, we can work this out once the patch is
finalized. This is not a hard dependency in that it only affects the
efficiency of idle injection.
next prev parent reply other threads:[~2015-11-16 23:16 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-13 19:53 [PATCH 0/4] CFS idle injection Jacob Pan
2015-11-13 19:53 ` [PATCH 1/4] ktime: add a roundup function Jacob Pan
2015-11-13 20:11 ` John Stultz
2015-11-13 22:33 ` Jacob Pan
2015-11-13 20:13 ` Thomas Gleixner
2015-11-13 22:36 ` Jacob Pan
2015-11-13 19:53 ` [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan
2015-11-13 20:22 ` Thomas Gleixner
2015-11-13 22:24 ` Jacob Pan
2015-11-16 15:06 ` Thomas Gleixner
2015-11-16 21:51 ` Jacob Pan
2015-11-16 22:01 ` Thomas Gleixner
2015-11-17 0:09 ` Jacob Pan
2015-11-19 17:43 ` Jacob Pan
2015-11-19 19:06 ` Peter Zijlstra
2015-11-19 19:21 ` Jacob Pan
2015-11-19 19:59 ` Peter Zijlstra
2015-11-19 23:41 ` Jacob Pan
2015-11-16 22:31 ` Paul E. McKenney
2015-11-16 23:05 ` Jacob Pan
2015-11-16 23:15 ` Jacob Pan [this message]
2015-11-16 23:28 ` Paul E. McKenney
2015-11-16 23:32 ` Arjan van de Ven
2015-11-16 23:40 ` Jacob Pan
2015-11-17 0:00 ` Paul E. McKenney
2015-11-16 22:32 ` Josh Triplett
2015-11-16 23:26 ` Paul E. McKenney
2015-11-17 1:41 ` Josh Triplett
2015-11-17 2:53 ` Paul E. McKenney
2015-11-17 2:57 ` Arjan van de Ven
2015-11-17 5:04 ` Paul E. McKenney
2015-11-17 10:24 ` Peter Zijlstra
2015-11-17 12:57 ` Jacob Pan
2015-11-17 13:49 ` Paul E. McKenney
2015-11-13 19:53 ` [PATCH 3/4] sched: introduce synchronized idle injection Jacob Pan
2015-11-13 20:23 ` kbuild test robot
2015-11-18 8:36 ` Ingo Molnar
2015-11-18 10:35 ` Peter Zijlstra
2015-11-18 12:27 ` Morten Rasmussen
2015-11-18 12:49 ` Peter Zijlstra
2015-11-18 14:04 ` Morten Rasmussen
2015-11-18 14:52 ` Jacob Pan
2015-11-18 15:09 ` Morten Rasmussen
2015-11-18 15:11 ` Jacob Pan
2015-11-18 15:21 ` Thomas Gleixner
2015-11-18 17:03 ` Jacob Pan
2015-11-18 16:04 ` Morten Rasmussen
2015-11-27 9:17 ` Ingo Molnar
2015-11-18 14:10 ` Jacob Pan
2015-11-27 9:17 ` Ingo Molnar
2015-12-02 17:28 ` Jacob Pan
2015-11-18 14:19 ` Arjan van de Ven
2015-11-18 15:44 ` Morten Rasmussen
2015-11-18 15:51 ` Arjan van de Ven
2015-11-19 17:24 ` Morten Rasmussen
2015-11-19 20:09 ` Peter Zijlstra
2015-11-20 9:45 ` Thomas Gleixner
2015-11-20 10:20 ` Peter Zijlstra
2015-11-20 10:58 ` Thomas Gleixner
2015-11-20 12:54 ` Peter Zijlstra
2015-11-20 18:53 ` Thomas Gleixner
2016-01-11 21:50 ` Jacob Pan
2016-01-19 12:06 ` Ingo Molnar
2016-01-19 18:00 ` Jacob Pan
2015-11-24 11:38 ` Jacob Pan
2015-11-23 17:59 ` Jacob Pan
2015-11-23 17:56 ` Javi Merino
2015-11-23 18:07 ` Peter Zijlstra
2015-11-24 9:12 ` Javi Merino
2015-11-24 10:09 ` Peter Zijlstra
2015-11-24 11:10 ` Jacob Pan
2015-11-24 12:00 ` Javi Merino
2015-11-24 18:22 ` Jacob Pan
2015-11-25 9:41 ` Javi Merino
2015-11-13 19:53 ` [PATCH 4/4] sched: add trace event for " Jacob Pan
2015-11-13 20:10 ` kbuild test robot
2015-11-19 14:39 ` Javi Merino
2015-11-19 15:35 ` Jacob Pan
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