From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Christoph Lameter <cl@linux.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
Chris Metcalf <cmetcalf@ezchip.com>,
Gilad Ben Yossef <giladb@ezchip.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>, Tejun Heo <tj@kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Viresh Kumar <viresh.kumar@linaro.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 1/5] nohz_full: add support for "cpu_isolated" mode
Date: Wed, 22 Jul 2015 12:28:34 -0700 [thread overview]
Message-ID: <20150722192834.GA32511@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.11.1507220856030.17411@east.gentwo.org>
On Wed, Jul 22, 2015 at 08:57:45AM -0500, Christoph Lameter wrote:
> On Tue, 21 Jul 2015, Paul E. McKenney wrote:
>
> > > > In the current version, there's also the vmstat_update() that
> > > > may schedule delayed work and interrupt the core again
> > > > shortly before realizing that there are no more counter updates
> > > > happening, at which point it quiesces. Currently we handle
> > > > this in cpu_isolated mode simply by spinning and waiting for
> > > > the timer interrupts to complete.
> > >
> > > Perhaps we should fix that?
> >
> > Didn't Christoph Lameter fix this? Or is this an additional problem?
>
> Well the vmstat update must realize first that there are no outstanding
> updates before switching itself off. So typically there is one extra tick.
> But we could add another function that will simply fold the differential
> immediately and turn the kworker task in the expectation that the
> processor will stay quiet.
Got it, thank you!
Thanx, Paul
next prev parent reply other threads:[~2015-07-22 19:28 UTC|newest]
Thread overview: 236+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-08 17:58 [PATCH 0/6] support "dataplane" mode for nohz_full Chris Metcalf
2015-05-08 17:58 ` [PATCH 1/6] nohz_full: add support for "dataplane" mode Chris Metcalf
2015-05-08 17:58 ` [PATCH 2/6] nohz: dataplane: allow tick to be fully disabled for dataplane Chris Metcalf
2015-05-12 9:26 ` Peter Zijlstra
2015-05-12 13:12 ` Paul E. McKenney
2015-05-14 20:55 ` Chris Metcalf
2015-05-08 17:58 ` [PATCH 3/6] dataplane nohz: run softirqs synchronously on user entry Chris Metcalf
2015-05-09 7:04 ` Mike Galbraith
2015-05-11 20:13 ` Chris Metcalf
2015-05-12 2:21 ` Mike Galbraith
2015-05-12 9:28 ` Peter Zijlstra
2015-05-12 9:32 ` Peter Zijlstra
2015-05-12 13:08 ` Paul E. McKenney
2015-05-08 17:58 ` [PATCH 4/6] nohz: support PR_DATAPLANE_QUIESCE Chris Metcalf
2015-05-12 9:33 ` Peter Zijlstra
2015-05-12 9:50 ` Ingo Molnar
2015-05-12 10:38 ` Peter Zijlstra
2015-05-12 12:52 ` Ingo Molnar
2015-05-13 4:35 ` Andy Lutomirski
2015-05-13 17:51 ` Paul E. McKenney
2015-05-14 20:55 ` Chris Metcalf
2015-05-14 20:54 ` Chris Metcalf
2015-05-08 17:58 ` [PATCH 5/6] nohz: support PR_DATAPLANE_STRICT mode Chris Metcalf
2015-05-09 7:28 ` Andy Lutomirski
2015-05-09 10:37 ` Gilad Ben Yossef
2015-05-11 19:13 ` Chris Metcalf
2015-05-11 22:28 ` Andy Lutomirski
2015-05-12 21:06 ` Chris Metcalf
2015-05-12 22:23 ` Andy Lutomirski
2015-05-15 21:25 ` Chris Metcalf
2015-05-12 9:38 ` Peter Zijlstra
2015-05-12 13:20 ` Paul E. McKenney
2015-05-08 17:58 ` [PATCH 6/6] nohz: add dataplane_debug boot flag Chris Metcalf
2015-05-08 21:18 ` [PATCH 0/6] support "dataplane" mode for nohz_full Andrew Morton
2015-05-08 21:22 ` Steven Rostedt
2015-05-08 23:11 ` Chris Metcalf
2015-05-08 23:19 ` Andrew Morton
2015-05-09 7:05 ` Ingo Molnar
2015-05-09 7:19 ` Andy Lutomirski
2015-05-11 19:54 ` Chris Metcalf
2015-05-11 22:15 ` Andy Lutomirski
[not found] ` <55510885.9070101@ezchip.com>
2015-05-12 13:18 ` Paul E. McKenney
2015-05-09 7:19 ` Mike Galbraith
2015-05-09 10:18 ` Gilad Ben Yossef
2015-05-11 12:57 ` Steven Rostedt
2015-05-11 15:36 ` Frederic Weisbecker
2015-05-11 19:19 ` Mike Galbraith
2015-05-11 19:25 ` Chris Metcalf
2015-05-12 1:47 ` Mike Galbraith
2015-05-12 4:35 ` Mike Galbraith
2015-05-15 15:05 ` Chris Metcalf
2015-05-15 18:44 ` Mike Galbraith
2015-05-26 19:51 ` Chris Metcalf
2015-05-27 3:28 ` Mike Galbraith
2015-05-11 17:19 ` Paul E. McKenney
2015-05-11 17:27 ` Andrew Morton
2015-05-11 17:33 ` Frederic Weisbecker
2015-05-11 18:00 ` Steven Rostedt
2015-05-11 18:09 ` Chris Metcalf
2015-05-11 18:36 ` Steven Rostedt
2015-05-12 9:10 ` CONFIG_ISOLATION=y (was: [PATCH 0/6] support "dataplane" mode for nohz_full) Ingo Molnar
2015-05-12 11:48 ` Peter Zijlstra
2015-05-12 12:34 ` Ingo Molnar
2015-05-12 12:39 ` Peter Zijlstra
2015-05-12 12:43 ` Ingo Molnar
2015-05-12 15:36 ` Frederic Weisbecker
2015-05-12 21:05 ` CONFIG_ISOLATION=y Chris Metcalf
2015-05-12 10:46 ` [PATCH 0/6] support "dataplane" mode for nohz_full Peter Zijlstra
2015-05-15 15:10 ` Chris Metcalf
2015-05-15 21:26 ` [PATCH v2 0/5] support "cpu_isolated" " Chris Metcalf
2015-05-15 21:27 ` [PATCH v2 1/5] nohz_full: add support for "cpu_isolated" mode Chris Metcalf
2015-05-15 21:27 ` [PATCH v2 2/5] nohz: support PR_CPU_ISOLATED_STRICT mode Chris Metcalf
2015-05-15 21:27 ` [PATCH v2 3/5] nohz: cpu_isolated strict mode configurable signal Chris Metcalf
2015-05-15 21:27 ` [PATCH v2 4/5] nohz: add cpu_isolated_debug boot flag Chris Metcalf
2015-05-15 21:27 ` [PATCH v2 5/5] nohz: cpu_isolated: allow tick to be fully disabled Chris Metcalf
2015-05-15 22:17 ` [PATCH v2 1/5] nohz_full: add support for "cpu_isolated" mode Thomas Gleixner
2015-05-28 20:38 ` Chris Metcalf
2015-06-03 15:29 ` [PATCH v3 0/5] support "cpu_isolated" mode for nohz_full Chris Metcalf
2015-06-03 15:29 ` [PATCH v3 1/5] nohz_full: add support for "cpu_isolated" mode Chris Metcalf
2015-06-03 15:29 ` [PATCH v3 2/5] nohz: support PR_CPU_ISOLATED_STRICT mode Chris Metcalf
2015-06-03 15:29 ` [PATCH v3 3/5] nohz: cpu_isolated strict mode configurable signal Chris Metcalf
2015-06-03 15:29 ` [PATCH v3 4/5] nohz: add cpu_isolated_debug boot flag Chris Metcalf
2015-06-03 15:29 ` [PATCH v3 5/5] nohz: cpu_isolated: allow tick to be fully disabled Chris Metcalf
2015-07-13 19:57 ` [PATCH v4 0/5] support "cpu_isolated" mode for nohz_full Chris Metcalf
2015-07-13 19:57 ` [PATCH v4 1/5] nohz_full: add support for "cpu_isolated" mode Chris Metcalf
2015-07-13 20:40 ` Andy Lutomirski
2015-07-13 21:01 ` Chris Metcalf
2015-07-13 21:45 ` Andy Lutomirski
2015-07-21 19:10 ` Chris Metcalf
2015-07-21 19:26 ` Andy Lutomirski
2015-07-21 20:36 ` Paul E. McKenney
2015-07-22 13:57 ` Christoph Lameter
2015-07-22 19:28 ` Paul E. McKenney [this message]
2015-07-22 20:02 ` Christoph Lameter
2015-07-24 20:21 ` Chris Metcalf
2015-07-24 20:22 ` Chris Metcalf
2015-07-24 14:03 ` Frederic Weisbecker
2015-07-24 20:19 ` Chris Metcalf
2015-07-24 13:27 ` Frederic Weisbecker
2015-07-24 20:21 ` Chris Metcalf
2015-07-13 19:57 ` [PATCH v4 2/5] nohz: support PR_CPU_ISOLATED_STRICT mode Chris Metcalf
2015-07-13 21:47 ` Andy Lutomirski
2015-07-21 19:34 ` Chris Metcalf
2015-07-21 19:42 ` Andy Lutomirski
2015-07-24 20:29 ` Chris Metcalf
2015-07-13 19:57 ` [PATCH v4 3/5] nohz: cpu_isolated strict mode configurable signal Chris Metcalf
2015-07-13 19:58 ` [PATCH v4 4/5] nohz: add cpu_isolated_debug boot flag Chris Metcalf
2015-07-13 19:58 ` [PATCH v4 5/5] nohz: cpu_isolated: allow tick to be fully disabled Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 0/6] support "cpu_isolated" mode for nohz_full Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 1/6] vmstat: provide a function to quiet down the diff processing Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 2/6] cpu_isolated: add initial support Chris Metcalf
2015-08-12 16:00 ` Frederic Weisbecker
2015-08-12 18:22 ` Chris Metcalf
2015-08-26 15:26 ` Frederic Weisbecker
2015-08-26 15:55 ` Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 3/6] cpu_isolated: support PR_CPU_ISOLATED_STRICT mode Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 4/6] cpu_isolated: provide strict mode configurable signal Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 5/6] cpu_isolated: add debug boot flag Chris Metcalf
2015-07-28 19:49 ` [PATCH v5 6/6] nohz: cpu_isolated: allow tick to be fully disabled Chris Metcalf
2015-08-25 19:55 ` [PATCH v6 0/6] support "task_isolated" mode for nohz_full Chris Metcalf
2015-08-25 19:55 ` [PATCH v6 1/6] vmstat: provide a function to quiet down the diff processing Chris Metcalf
2015-08-25 19:55 ` [PATCH v6 2/6] task_isolation: add initial support Chris Metcalf
2015-08-25 19:55 ` [PATCH v6 3/6] task_isolation: support PR_TASK_ISOLATION_STRICT mode Chris Metcalf
2015-08-26 10:36 ` Will Deacon
2015-08-26 15:10 ` Chris Metcalf
2015-09-02 10:13 ` Will Deacon
2015-09-02 18:38 ` [PATCH v6.2 " Chris Metcalf
2015-08-28 15:31 ` [PATCH v6.1 " Chris Metcalf
2015-08-25 19:55 ` [PATCH v6 4/6] task_isolation: provide strict mode configurable signal Chris Metcalf
2015-08-28 19:22 ` Andy Lutomirski
2015-08-25 19:55 ` [PATCH v6 5/6] task_isolation: add debug boot flag Chris Metcalf
2015-08-25 19:55 ` [PATCH v6 6/6] nohz: task_isolation: allow tick to be fully disabled Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 00/11] support "task_isolated" mode for nohz_full Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 01/11] vmstat: provide a function to quiet down the diff processing Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 02/11] task_isolation: add initial support Chris Metcalf
2015-10-01 12:14 ` Frederic Weisbecker
2015-10-01 12:18 ` Thomas Gleixner
2015-10-01 12:23 ` Frederic Weisbecker
2015-10-01 12:31 ` Thomas Gleixner
2015-10-01 17:02 ` Chris Metcalf
2015-10-01 21:20 ` Thomas Gleixner
2015-10-02 17:15 ` Chris Metcalf
2015-10-02 19:02 ` Thomas Gleixner
2015-10-01 19:25 ` Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 03/11] task_isolation: support PR_TASK_ISOLATION_STRICT mode Chris Metcalf
2015-09-28 20:51 ` Andy Lutomirski
2015-09-28 21:54 ` Chris Metcalf
2015-09-28 22:38 ` Andy Lutomirski
2015-09-29 17:35 ` Chris Metcalf
2015-09-29 17:46 ` Andy Lutomirski
2015-09-29 17:57 ` Chris Metcalf
2015-09-29 18:00 ` Andy Lutomirski
2015-10-01 19:25 ` Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 04/11] task_isolation: provide strict mode configurable signal Chris Metcalf
2015-09-28 20:54 ` Andy Lutomirski
2015-09-28 21:54 ` Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 05/11] task_isolation: add debug boot flag Chris Metcalf
2015-09-28 20:59 ` Andy Lutomirski
2015-09-28 21:55 ` Chris Metcalf
2015-09-28 22:40 ` Andy Lutomirski
2015-09-29 17:35 ` Chris Metcalf
2015-10-05 17:07 ` Luiz Capitulino
2015-10-08 0:33 ` Chris Metcalf
2015-10-08 20:28 ` Luiz Capitulino
2015-09-28 15:17 ` [PATCH v7 06/11] nohz: task_isolation: allow tick to be fully disabled Chris Metcalf
2015-09-28 20:40 ` Andy Lutomirski
2015-10-01 13:07 ` Frederic Weisbecker
2015-10-01 14:13 ` Thomas Gleixner
2015-09-28 15:17 ` [PATCH v7 07/11] arch/x86: enable task isolation functionality Chris Metcalf
2015-09-28 20:59 ` Andy Lutomirski
2015-09-28 21:57 ` Chris Metcalf
2015-09-28 22:43 ` Andy Lutomirski
2015-09-29 17:42 ` Chris Metcalf
2015-09-29 17:57 ` Andy Lutomirski
2015-09-30 20:25 ` Thomas Gleixner
2015-09-30 20:58 ` Chris Metcalf
2015-09-30 22:02 ` Thomas Gleixner
2015-09-30 22:11 ` Andy Lutomirski
2015-10-01 8:12 ` Thomas Gleixner
2015-10-01 9:08 ` Christoph Lameter
2015-10-01 10:10 ` Thomas Gleixner
2015-10-01 19:25 ` Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 08/11] arch/arm64: adopt prepare_exit_to_usermode() model from x86 Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 09/11] arch/arm64: enable task isolation functionality Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 10/11] arch/tile: adopt prepare_exit_to_usermode() model from x86 Chris Metcalf
2015-09-28 15:17 ` [PATCH v7 11/11] arch/tile: enable task isolation functionality Chris Metcalf
2015-10-20 20:35 ` [PATCH v8 00/14] support "task_isolation" mode for nohz_full Chris Metcalf
2015-10-20 20:35 ` [PATCH v8 01/14] vmstat: provide a function to quiet down the diff processing Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 02/14] vmstat: add vmstat_idle function Chris Metcalf
2015-10-20 20:45 ` Christoph Lameter
2015-10-20 20:36 ` [PATCH v8 03/14] lru_add_drain_all: factor out lru_add_drain_needed Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 04/14] task_isolation: add initial support Chris Metcalf
2015-10-20 20:56 ` Andy Lutomirski
2015-10-20 21:20 ` Chris Metcalf
2015-10-20 21:26 ` Andy Lutomirski
2015-10-21 0:29 ` Steven Rostedt
2015-10-26 20:19 ` Chris Metcalf
2015-10-26 21:13 ` Chris Metcalf
2015-10-26 20:32 ` Chris Metcalf
2015-10-21 16:12 ` Frederic Weisbecker
2015-10-27 16:40 ` Chris Metcalf
2016-01-28 16:38 ` Frederic Weisbecker
2016-02-11 19:58 ` Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 05/14] task_isolation: support PR_TASK_ISOLATION_STRICT mode Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 06/14] task_isolation: provide strict mode configurable signal Chris Metcalf
2015-10-21 0:56 ` Steven Rostedt
2015-10-21 1:30 ` Chris Metcalf
2015-10-21 1:41 ` Steven Rostedt
2015-10-21 1:42 ` Andy Lutomirski
2015-10-21 6:41 ` Gilad Ben Yossef
2015-10-21 18:53 ` Andy Lutomirski
2015-10-22 20:44 ` Chris Metcalf
2015-10-22 21:00 ` Andy Lutomirski
2015-10-27 19:37 ` Chris Metcalf
2015-10-24 9:16 ` Gilad Ben Yossef
2015-10-20 20:36 ` [PATCH v8 07/14] task_isolation: add debug boot flag Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 08/14] nohz_full: allow disabling the 1Hz minimum tick at boot Chris Metcalf
2015-10-20 21:03 ` Frederic Weisbecker
2015-10-20 21:18 ` Chris Metcalf
2015-10-21 0:59 ` Steven Rostedt
2015-10-21 6:56 ` Gilad Ben Yossef
2015-10-21 14:28 ` Christoph Lameter
2015-10-21 15:35 ` Frederic Weisbecker
2015-10-20 20:36 ` [PATCH v8 09/14] arch/x86: enable task isolation functionality Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 10/14] arch/arm64: adopt prepare_exit_to_usermode() model from x86 Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 11/14] arch/arm64: enable task isolation functionality Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 12/14] arch/tile: adopt prepare_exit_to_usermode() model from x86 Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 13/14] arch/tile: turn off timer tick for oneshot_stopped state Chris Metcalf
2015-10-20 20:36 ` [PATCH v8 14/14] arch/tile: enable task isolation functionality Chris Metcalf
2015-10-21 12:39 ` [PATCH v8 00/14] support "task_isolation" mode for nohz_full Peter Zijlstra
2015-10-22 20:31 ` Chris Metcalf
2015-10-23 2:33 ` Frederic Weisbecker
2015-10-23 8:49 ` Peter Zijlstra
2015-10-23 13:29 ` Frederic Weisbecker
2015-10-23 9:04 ` Peter Zijlstra
2015-10-23 11:52 ` Theodore Ts'o
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