From: sboyd@codeaurora•org (Stephen Boyd)
To: linux-arm-kernel@lists•infradead.org
Subject: [tip:timers/core] ARM: Kconfig: allow full nohz CPU accounting
Date: Mon, 28 Oct 2013 09:18:42 -0700 [thread overview]
Message-ID: <526E8E62.7070700@codeaurora.org> (raw)
In-Reply-To: <526DBEAA.4030707@linaro.org>
On 10/27/13 18:32, Kevin Hilman wrote:
> Hi Stephen,
>
> On 10/18/2013 09:37 AM, Stephen Boyd wrote:
>> On 10/16, Frederic Weisbecker wrote:
>>> On Thu, Oct 03, 2013 at 06:58:03AM -0700, tip-bot for Kevin Hilman wrote:
>>>> Commit-ID: 31c1fc8187158cb80ccd57c19e024c55af901797
>>>> Gitweb: http://git.kernel.org/tip/31c1fc8187158cb80ccd57c19e024c55af901797
>>>> Author: Kevin Hilman <khilman@linaro•org>
>>>> AuthorDate: Mon, 16 Sep 2013 15:28:22 -0700
>>>> Committer: Frederic Weisbecker <fweisbec@gmail•com>
>>>> CommitDate: Mon, 30 Sep 2013 15:37:05 +0200
>>>>
>>>> ARM: Kconfig: allow full nohz CPU accounting
>>>>
>>>> With the 64-bit requirement removed from VIRT_CPU_ACCOUNTING_GEN,
>>>> allow ARM platforms to enable it. Since VIRT_CPU_ACCOUNTING_GEN is a
>>>> dependency for full NO_HZ, this allows ARM platforms to enable full
>>>> NO_HZ as well.
>>> I realize that arm doesn't implement irq work raise. It hooks on the
>>> timer to execute pending irq work. You'll need to implement arch_irq_work_raise()
>>> and implement some sort of self IPI to trigger irq work. The full dynticks subsystem
>>> relies on that to work correctly. It often use that to re-evaluate and possibly restart
>>> the tick after scheduler, posix timer updates, etc...
>>>
>>> That notwithstanding that if you have no tick, tick based irq work can't
>>> work.
>>>
>> Something like this? The only problem is that this latches on to
>> the SMP support for IPIs. If CONFIG_SMP is disabled we won't get
>> arch_irq_work_raise() but perhaps that isn't so big of a deal? Or
>> we should think about exposing IPI support to UP systems on ARM.
> Care to submit a proper patch for this to LAKML? or if you prefer I can
> do it (keeping your authorship.) We need this for proper full NOHZ
> support on ARM. Thanks.
Sure no problem. Let me write up some sort of commit text and I'll send
it off again.
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
next prev parent reply other threads:[~2013-10-28 16:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-03 13:58 [tip:timers/core] ARM: Kconfig: allow full nohz CPU accounting tip-bot for Kevin Hilman
2013-10-16 12:14 ` Frederic Weisbecker
2013-10-18 16:37 ` Stephen Boyd
2013-10-25 9:38 ` Frederic Weisbecker
2013-10-28 1:32 ` Kevin Hilman
2013-10-28 16:18 ` Stephen Boyd [this message]
2013-10-28 18:25 ` [PATCH] ARM: Support arch_irq_work_raise() via self IPIs Stephen Boyd
2013-10-29 1:58 ` Kevin Hilman
2013-10-29 6:00 ` Stephen Boyd
2013-10-29 8:25 ` Frederic Weisbecker
2013-10-29 18:55 ` Kevin Hilman
2013-11-08 20:06 ` Olof Johansson
2013-11-08 20:45 ` Olof Johansson
2013-11-08 21:53 ` Stephen Boyd
2013-11-08 23:35 ` Olof Johansson
2013-11-08 23:39 ` Stephen Boyd
2013-11-09 0:01 ` Russell King - ARM Linux
2013-11-09 0:07 ` Olof Johansson
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