From: Francis Giraldeau <francis.giraldeau@gmail.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>,
Gilad Ben Yossef <giladb@mellanox.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.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>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Christoph Lameter <cl@linux.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Andy Lutomirski <luto@amacapital.net>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
linux-doc@vger.kernel.org, linux-api@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: Ping: [PATCH v15 00/13] support "task_isolation" mode
Date: Tue, 13 Sep 2016 12:00:33 -0400 [thread overview]
Message-ID: <6651d87b-d827-ad2e-a38c-278eb0427bdb@gmail.com> (raw)
In-Reply-To: <1790609.DoEbHQ4oEN@vostro.rjw.lan>
On 2016-09-12 08:05 PM, Rafael J. Wysocki wrote:
> On Monday, September 12, 2016 11:15:45 PM Rafael J. Wysocki wrote:
>> On Monday, September 12, 2016 06:14:44 PM Peter Zijlstra wrote:
>>> On Mon, Sep 12, 2016 at 12:01:58PM -0400, Chris Metcalf wrote:
>>>> On 9/7/2016 5:11 PM, Francis Giraldeau wrote:
>>>>> When running only the test_jitter(), the isolation mode is lost:
>>>>>
>>>>> [ 6741.566048] isolation/9515: task_isolation mode lost due to irq_work
>>>>>
>>>>> With ftrace (events/workqueue/workqueue_execute_start), I get a bit more info:
>>>>>
>>>>> kworker/1:1-676 [001] .... 6610.097128: workqueue_execute_start: work struct ffff8801a784ca20: function dbs_work_handler
>>>>>
>>>>> The governor was ondemand, so I tried to set the frequency scaling
>>>>> governor to performance, but that does not solve the issue.
>>>
>>> Rafael, I'm thinking the performance governor should be able to run
>>> without sending IPIs. Is there anything we can quickly do about that?
>>
>> The performance governor doesn't do any IPIs.
>>
>> At this point I'm not sure what's going on.
>
> I've just tried and switching over to the performance governor makes
> dbs_work_handler go away for me (w/ -rc4 with some extra irrelevant patches
> on top) as it should.
Ho gosh, the command "cpufreq-set -g performance" sets the governor only
for cpu0. I was expecting it to set for all cpus. The isolation test runs
on cpu1 and this cpu was still with ondemand governor. With performance
governor, the dbs_work_handler does not occurs anymore and the isolated
task is not preempted by that kworker thread anymore.
Sorry for the noise and thanks for checking!
Francis
next prev parent reply other threads:[~2016-09-13 16:00 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-16 21:19 [PATCH v15 00/13] support "task_isolation" mode Chris Metcalf
2016-08-16 21:19 ` [PATCH v15 04/13] task_isolation: add initial support Chris Metcalf
2016-08-29 16:33 ` Peter Zijlstra
2016-08-29 16:40 ` Chris Metcalf
2016-08-29 16:48 ` Peter Zijlstra
2016-08-29 16:53 ` Chris Metcalf
2016-08-30 7:59 ` Peter Zijlstra
2016-08-30 7:58 ` Peter Zijlstra
[not found] ` <20160830075854.GZ10153-ndre7Fmf5hadTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2016-08-30 15:32 ` Chris Metcalf
2016-08-30 16:30 ` Andy Lutomirski
2016-08-30 17:02 ` Chris Metcalf
2016-08-30 18:43 ` Andy Lutomirski
2016-08-30 19:37 ` Chris Metcalf
2016-08-30 19:50 ` Andy Lutomirski
2016-09-02 14:04 ` Chris Metcalf
[not found] ` <3f84f736-ed7f-adff-d5f0-4f7db664208f-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2016-09-02 17:28 ` Andy Lutomirski
2016-09-09 17:40 ` Chris Metcalf
2016-09-12 17:41 ` Andy Lutomirski
2016-09-12 19:25 ` Chris Metcalf
2016-09-27 14:22 ` Frederic Weisbecker
2016-09-27 14:39 ` Peter Zijlstra
2016-09-27 14:51 ` Frederic Weisbecker
2016-09-27 14:48 ` Paul E. McKenney
2016-09-30 16:59 ` Chris Metcalf
2016-09-01 10:06 ` Peter Zijlstra
2016-09-02 14:03 ` Chris Metcalf
2016-09-02 16:40 ` Peter Zijlstra
2016-08-16 21:19 ` [PATCH v15 12/13] task_isolation: add user-settable notification signal Chris Metcalf
[not found] ` <1471382376-5443-1-git-send-email-cmetcalf-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2016-08-17 19:37 ` [PATCH] Fix /proc/stat freezes (was [PATCH v15] "task_isolation" mode) Christoph Lameter
2016-08-20 1:42 ` Chris Metcalf
2016-09-28 13:16 ` Frederic Weisbecker
2016-08-29 16:27 ` Ping: [PATCH v15 00/13] support "task_isolation" mode Chris Metcalf
2016-09-07 21:11 ` Francis Giraldeau
[not found] ` <057a958c-4491-b449-ae59-7d331afc872d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-09-07 21:39 ` Francis Giraldeau
2016-09-08 16:21 ` Francis Giraldeau
2016-09-12 16:01 ` Chris Metcalf
2016-09-12 16:14 ` Peter Zijlstra
2016-09-12 21:15 ` Rafael J. Wysocki
2016-09-13 0:05 ` Rafael J. Wysocki
2016-09-13 16:00 ` Francis Giraldeau [this message]
2016-09-13 0:20 ` Francis Giraldeau
[not found] ` <3e93004f-e1c5-f606-33fb-7cb44b99eb0a-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-09-13 16:12 ` Chris Metcalf
2016-09-27 14:49 ` Frederic Weisbecker
2016-09-27 14:35 ` Frederic Weisbecker
2016-09-30 17:07 ` Chris Metcalf
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