From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Sebastian Siewior <bigeasy@linutronix.de>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
"David S. Miller" <davem@davemloft.net>,
Fenghua Yu <fenghua.yu@intel.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Len Brown <lenb@kernel.org>,
Michael Ellerman <mpe@ellerman.id.au>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Tejun Heo <tj@kernel.org>, Tony Luck <tony.luck@intel.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
linux-acpi@vger.kernel.org
Subject: Re: [patch 08/13] ACPI/processor: Replace racy task affinity logic.
Date: Thu, 13 Apr 2017 14:52:24 +0200 [thread overview]
Message-ID: <20170413125224.5uu36nekq4r72b4y@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <alpine.DEB.2.20.1704131345160.2408@nanos>
On Thu, Apr 13, 2017 at 02:01:42PM +0200, Thomas Gleixner wrote:
> On Thu, 13 Apr 2017, Peter Zijlstra wrote:
> >
> > That makes my machine sad...
> > [ 9.786610] work_on_cpu+0x82/0x90
> > [ 9.790404] ? __usermodehelper_disable+0x110/0x110
> > [ 9.795846] ? __acpi_processor_get_throttling+0x20/0x20
> > [ 9.801773] acpi_processor_set_throttling+0x199/0x220
> > [ 9.807506] ? trace_hardirqs_on_caller+0xfb/0x1d0
> > [ 9.812851] acpi_processor_get_throttling_ptc+0xec/0x180
> > [ 9.818876] __acpi_processor_get_throttling+0xf/0x20
> > [ 9.824511] work_for_cpu_fn+0x14/0x20
> > [ 9.828692] process_one_work+0x261/0x670
> > [ 9.833165] worker_thread+0x21b/0x3f0
> > [ 9.837348] kthread+0x108/0x140
> > [ 9.840947] ? process_one_work+0x670/0x670
> > [ 9.845611] ? kthread_create_on_node+0x40/0x40
> > [ 9.850667] ret_from_fork+0x31/0x40
>
> Yuck. So the call chain is:
>
> acpi_processor_get_throttling()
> work_on_cpu(acpi_processor_get_throttling)
>
> That work does:
>
> __acpi_processor_get_throttling()
> acpi_processor_get_throttling_ptc()
> acpi_processor_set_throttling()
> work_on_cpu(__acpi_processor_set_throttling)
>
> Why the heck calls a get_throttling() function set_throttling()? I'm mildly
> surprised.
>
> Does the delta patch below cure the problem?
Yes, aside from a compile warn.
But that's disgusting... then again, you merely reintroduced this hack.
next prev parent reply other threads:[~2017-04-13 12:52 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-12 20:07 [patch 00/13] sched/treewide: Clean up various racy task affinity issues Thomas Gleixner
2017-04-12 20:07 ` [patch 01/13] ia64/topology: Remove cpus_allowed manipulation Thomas Gleixner
2017-04-15 14:15 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 02/13] workqueue: Provide work_on_cpu_safe() Thomas Gleixner
2017-04-13 11:11 ` Dou Liyang
2017-04-13 21:28 ` Thomas Gleixner
2017-04-14 4:18 ` Tejun Heo
2017-04-14 8:54 ` Peter Zijlstra
2017-04-14 9:51 ` Thomas Gleixner
2017-04-14 9:56 ` Peter Zijlstra
2017-04-15 14:16 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 03/13] ia64/salinfo: Replace racy task affinity logic Thomas Gleixner
2017-04-15 14:17 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 04/13] ia64/sn/hwperf: " Thomas Gleixner
2017-04-12 20:53 ` [patch V 2 " Thomas Gleixner
2017-04-15 14:17 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 05/13] powerpc/smp: Replace open coded " Thomas Gleixner
2017-04-13 5:47 ` Michael Ellerman
2017-04-15 14:18 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 06/13] sparc/sysfs: Replace racy " Thomas Gleixner
2017-04-13 1:52 ` David Miller
2017-04-13 8:17 ` [patch V2 " Thomas Gleixner
2017-04-15 14:18 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 07/13] ACPI/processor: Fix error handling in __acpi_processor_start() Thomas Gleixner
2017-04-15 14:19 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 08/13] ACPI/processor: Replace racy task affinity logic Thomas Gleixner
2017-04-13 11:39 ` Peter Zijlstra
2017-04-13 12:01 ` Thomas Gleixner
2017-04-13 12:52 ` Peter Zijlstra [this message]
2017-04-15 14:19 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 09/13] cpufreq/ia64: " Thomas Gleixner
2017-04-12 20:55 ` [patch V2 " Thomas Gleixner
2017-04-15 14:20 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-13 2:42 ` [patch 09/13] " Viresh Kumar
2017-04-12 20:07 ` [patch 10/13] cpufreq/sh: " Thomas Gleixner
2017-04-13 2:46 ` Viresh Kumar
2017-04-15 14:20 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 11/13] cpufreq/sparc-us3: " Thomas Gleixner
2017-04-13 2:48 ` Viresh Kumar
2017-04-15 14:21 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-12 20:07 ` [patch 12/13] cpufreq/sparc-us2e: " Thomas Gleixner
2017-04-13 2:50 ` Viresh Kumar
2017-04-13 8:19 ` [patch V2 " Thomas Gleixner
2017-04-13 8:22 ` [patch V3 " Thomas Gleixner
2017-04-15 14:21 ` [tip:sched/core] " tip-bot for Thomas Gleixner
2017-04-13 14:50 ` [patch V2 12/13] " David Miller
2017-04-12 20:07 ` [patch 13/13] crypto: n2 - " Thomas Gleixner
2017-04-13 4:56 ` Herbert Xu
2017-04-13 8:20 ` [patch V2 " Thomas Gleixner
2017-04-13 14:51 ` David Miller
2017-04-15 14:22 ` [tip:sched/core] crypto: N2 " tip-bot for Thomas Gleixner
2017-04-13 9:02 ` [patch 00/13] sched/treewide: Clean up various racy task affinity issues Peter Zijlstra
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=20170413125224.5uu36nekq4r72b4y@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=benh@kernel.crashing.org \
--cc=bigeasy@linutronix.de \
--cc=davem@davemloft.net \
--cc=fenghua.yu@intel.com \
--cc=herbert@gondor.apana.org.au \
--cc=jiangshanlai@gmail.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=mpe@ellerman.id.au \
--cc=rjw@rjwysocki.net \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
--cc=tony.luck@intel.com \
--cc=viresh.kumar@linaro.org \
/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).