From: Sudeep Holla <sudeep.holla@arm.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Sudeep Holla <sudeep.holla@arm.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Linux PM list <linux-pm@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH 16/20] sched/idle: Use explicit broadcast oneshot control function
Date: Tue, 28 Apr 2015 14:58:37 +0100 [thread overview]
Message-ID: <553F920D.6090404@arm.com> (raw)
In-Reply-To: <21687949.Wq8byZT4f8@vostro.rjw.lan>
On 28/04/15 15:14, Rafael J. Wysocki wrote:
> On Tuesday, April 28, 2015 03:37:44 PM Rafael J. Wysocki wrote:
>> On Tuesday, April 28, 2015 03:31:54 PM Rafael J. Wysocki wrote:
>>> On Tuesday, April 28, 2015 02:37:10 PM Linus Walleij wrote:
>>>> On Tue, Apr 28, 2015 at 2:19 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
>>>>> Sudeep:
>>>>>> At-least I observed issue only when I am using hardware broadcast timer.
>>>>>> It doesn't hang when I am using hrtimer as broadcast timer in which case
>>>>>> one of the cpu will be not enter deeper idle states that lose timer.
>>>>>> I will rerun on v4.1-rc1 and post the complete log.
>>>>>
>>>>> So the bug here is that cpuidle_enter() enables interrupts, so the
>>>>> assumption about them being not enabled made by
>>>>> tick_broadcast_oneshot_control() is actually not valid.
>>>>>
>>>>> It looks like we need to acquire the clockevents_lock at least in this
>>>>> particular case. Let me see where to put it and I'll send a patch for
>>>>> testing.
>>>>
>>>> Aha that looks very much like it. Put me on the patch and I'll
>>>> take it for a spin.
>>>
>>> OK, so something like the below for starters (the _irqsave variant is used to
>>> avoid adding one more WARN_ON(irqs_disabled()) in there).
>>>
>>> I haven't tested it, but then I can't reproduce the original issue in the
>>> first place.
>>
>> Of course, the whole "broadcast" thing could be done from cpuidle_enter()
>> in the first place, but then we could not avoid the problem with the cpuidle
>> *callback* enabling interrupts possibly in there anyway (not to mention the
>> "coupled" stuff).
>
> That said, if the given state is marked with CPUIDLE_FLAG_TIMER_STOP, I really
> wouldn't expect it to re-enable interrupts on exit and the "coupled" thing
> seems to be fundamentally at odds with that flag either.
>
> So it should be possible to move the "broadcast" logic into the cpuidle layer,
> which I'm going to try to do.
>
Makes sense.
> Please test the patch I've sent, though, as it should bring the code back to
> where it was before the clockevents_notify() removal and it'd be good to verify
> that.
>
I tested your patch and it works now. Anyways I am continuing to run
stress tests on my board. I will report if I find any issues.
Regards,
Sudeep
next prev parent reply other threads:[~2015-04-28 13:58 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-01 22:02 [PATCH 00/20] clockevents_notify() removal Rafael J. Wysocki
2015-04-01 22:03 ` [PATCH 01/20] clockevents: Provide explicit broadcast control functions Rafael J. Wysocki
2015-04-01 22:04 ` [PATCH 02/20] x86, amd_idle: Use explicit broadcast control function Rafael J. Wysocki
2015-04-01 22:05 ` [PATCH 03/20] ACPI / PAD: " Rafael J. Wysocki
2015-04-01 22:06 ` [PATCH 04/20] ACPI / processor: " Rafael J. Wysocki
2015-04-01 22:07 ` [PATCH 05/20] cpuidle: " Rafael J. Wysocki
2015-04-01 22:09 ` [PATCH 06/20] intel_idle: " Rafael J. Wysocki
2015-04-01 22:10 ` [PATCH 07/20] ARM: OMAP: " Rafael J. Wysocki
2015-04-01 22:11 ` [PATCH 08/20] clockevents: Remove the broadcast control leftovers Rafael J. Wysocki
2015-04-01 22:13 ` [PATCH 09/20] clockevents: Provide explicit broadcast oneshot control functions Rafael J. Wysocki
2015-04-01 22:15 ` [PATCH 10/20] x86, amd_idle: Use " Rafael J. Wysocki
2015-04-01 22:16 ` [PATCH 11/20] ACPI / PAD: Use explicit broadcast oneshot control function Rafael J. Wysocki
2015-04-01 22:17 ` [PATCH 12/20] ACPI / processor: Use explicit broadcast controll function Rafael J. Wysocki
2015-04-01 22:20 ` [PATCH 13/20] intel_idle: Use explicit broadcast oneshot control function Rafael J. Wysocki
2015-04-01 22:20 ` [PATCH 14/20] ARM: OMAP: " Rafael J. Wysocki
2015-04-01 22:21 ` [PATCH 15/20] ARM: tegra: " Rafael J. Wysocki
2015-04-01 22:22 ` [PATCH 16/20] sched/idle: " Rafael J. Wysocki
2015-04-28 10:11 ` Linus Walleij
2015-04-28 10:17 ` Sudeep Holla
2015-04-28 10:34 ` Daniel Lezcano
2015-04-28 10:42 ` Sudeep Holla
2015-04-28 12:19 ` Rafael J. Wysocki
2015-04-28 12:37 ` Linus Walleij
2015-04-28 13:31 ` Rafael J. Wysocki
2015-04-28 13:37 ` Rafael J. Wysocki
2015-04-28 14:14 ` Rafael J. Wysocki
2015-04-28 13:58 ` Sudeep Holla [this message]
2015-04-29 0:50 ` Rafael J. Wysocki
2015-04-29 1:04 ` Rafael J. Wysocki
2015-04-29 7:10 ` Linus Walleij
2015-04-29 8:57 ` Peter Zijlstra
2015-04-29 9:44 ` Daniel Lezcano
2015-04-29 9:50 ` Sudeep Holla
2015-04-29 14:07 ` [PATCH][Fix] cpuidle: Run tick_broadcast_exit() with disabled interrupts Rafael J. Wysocki
2015-04-30 3:47 ` Preeti U Murthy
2015-04-30 20:12 ` Nicolas Pitre
2015-04-30 22:10 ` Rafael J. Wysocki
2015-04-30 3:45 ` [PATCH 16/20] sched/idle: Use explicit broadcast oneshot control function Preeti U Murthy
2015-04-28 13:04 ` Sudeep Holla
2015-04-01 22:23 ` [PATCH 17/20] clockevents: Remove broadcast oneshot control leftovers Rafael J. Wysocki
2015-04-01 22:24 ` [PATCH 18/20] clockevents: Make tick handover explicit Rafael J. Wysocki
2015-04-01 22:25 ` [PATCH 19/20] clockevents: Cleanup dead cpu explicitely Rafael J. Wysocki
2015-04-01 22:26 ` [PATCH 20/20] timekeeping: Get rid of stale comment Rafael J. Wysocki
2015-04-01 23:57 ` John Stultz
2015-04-02 12:39 ` [PATCH 00/20] clockevents_notify() removal Ingo Molnar
2015-04-02 22:19 ` Rafael J. Wysocki
2015-04-02 23:45 ` [v2][PATCH 00/21] " Rafael J. Wysocki
2015-04-02 23:46 ` [v2][PATCH 01/21] ACPI / PAD: Remove the local APIC nonsense Rafael J. Wysocki
2015-04-03 8:21 ` [tip:timers/core] ACPI/PAD: " tip-bot for Thomas Gleixner
2015-04-03 0:01 ` [v2][PATCH 02/21] clockevents: Provide explicit broadcast control functions Rafael J. Wysocki
2015-04-03 8:21 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:01 ` [v2][PATCH 03/21] x86, amd_idle: Use explicit broadcast control function Rafael J. Wysocki
2015-04-03 8:22 ` [tip:timers/core] x86/amd/idle, clockevents: " tip-bot for Thomas Gleixner
2015-04-03 0:01 ` [v2][PATCH 04/21] ACPI / PAD: " Rafael J. Wysocki
2015-04-03 8:22 ` [tip:timers/core] ACPI/PAD: " tip-bot for Thomas Gleixner
2015-04-03 0:02 ` [v2][PATCH 05/21] ACPI / processor: " Rafael J. Wysocki
2015-04-03 8:22 ` [tip:timers/core] ACPI/processor: " tip-bot for Thomas Gleixner
2015-04-03 0:02 ` [v2][PATCH 06/21] cpuidle: " Rafael J. Wysocki
2015-04-03 8:23 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:02 ` [v2][PATCH 07/21] intel_idle: " Rafael J. Wysocki
2015-04-03 8:23 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:02 ` [v2][PATCH 08/21] ARM: OMAP: " Rafael J. Wysocki
2015-04-03 8:23 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:03 ` [v2][PATCH 09/21] clockevents: Remove the broadcast control leftovers Rafael J. Wysocki
2015-04-03 8:23 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:05 ` [v2][PATCH 10/21] clockevents: Provide explicit broadcast oneshot control functions Rafael J. Wysocki
2015-04-03 8:24 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:05 ` [v2][PATCH 11/21] x86, amd_idle: Use " Rafael J. Wysocki
2015-04-03 8:24 ` [tip:timers/core] x86/amd/idle, clockevents: " tip-bot for Thomas Gleixner
2015-04-03 0:06 ` [v2][PATCH 12/21] ACPI / PAD: Use explicit broadcast oneshot control function Rafael J. Wysocki
2015-04-03 8:24 ` [tip:timers/core] ACPI/PAD: " tip-bot for Thomas Gleixner
2015-04-03 0:12 ` [v2][PATCH 13/21] ACPI / processor: Use explicit broadcast controll function Rafael J. Wysocki
2015-04-03 8:25 ` [tip:timers/core] ACPI/idle: Use explicit broadcast control function tip-bot for Thomas Gleixner
2015-04-03 0:14 ` [v2][PATCH 14/21] intel_idle: Use explicit broadcast oneshot " Rafael J. Wysocki
2015-04-03 8:25 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:31 ` [v2][PATCH 15/21] ARM: OMAP: " Rafael J. Wysocki
2015-04-03 8:25 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:32 ` [v2][PATCH 16/21] ARM: tegra: " Rafael J. Wysocki
2015-04-03 8:25 ` [tip:timers/core] ARM: Tegra: " tip-bot for Thomas Gleixner
2015-04-03 0:34 ` [v2][PATCH 17/21] sched/idle: " Rafael J. Wysocki
2015-04-03 8:26 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:36 ` [v2][PATCH 18/21] clockevents: Remove broadcast oneshot control leftovers Rafael J. Wysocki
2015-04-03 8:26 ` [tip:timers/core] " tip-bot for Rafael J. Wysocki
2015-04-03 0:37 ` [v2][PATCH 19/21] clockevents: Make tick handover explicit Rafael J. Wysocki
2015-04-03 8:26 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:38 ` [v2][PATCH 20/21] clockevents: Cleanup dead cpu explicitely Rafael J. Wysocki
2015-04-03 8:26 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 0:39 ` [v2][PATCH 21/21] timekeeping: Get rid of stale comment Rafael J. Wysocki
2015-04-03 8:27 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2015-04-03 6:45 ` [v2][PATCH 00/21] clockevents_notify() removal Ingo Molnar
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