From: Jacek Anaszewski <j.anaszewski@samsung.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
rt@linutronix.de, Richard Cochran <rcochran@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linus Walleij <linus.walleij@linaro.org>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Richard Purdie <rpurdie@rpsys.net>,
linux-leds@vger.kernel.org, Pawel Moll <pawel.moll@arm.com>
Subject: Re: [patch V2 43/67] leds/trigger/cpu: Convert to hotplug state machine
Date: Mon, 18 Jul 2016 10:26:36 +0200 [thread overview]
Message-ID: <578C92BC.2070603@samsung.com> (raw)
In-Reply-To: <20160715141026.GA16938@linutronix.de>
Hi Sebastian,
On 07/15/2016 04:10 PM, Sebastian Andrzej Siewior wrote:
> * Jacek Anaszewski | 2016-07-14 13:55:26 [+0200]:
>
>> On 07/14/2016 01:33 PM, Thomas Gleixner wrote:
>>> That does not explain WHY this needs to happen in the low level bringup phase
>>> of the CPU with interrupts disabled and can't be done from the normal ONLINE
>>> callbacks in thread context.
>>
>> It was before my time in kernel, so I can only suppose that it was
>> the easiest way. Does it introduce some problems?
>
> It was introduced by Pawel Moll in fba14ae8e924 ("ledtrig-cpu: Handle
> CPU hot(un)plugging"). It does not introduce any problems but those
> bring up / bring down levels are usually used by the core code. This
> does not look like it needs to be done _that_ early or late during the
> removal / addition of a CPU to the system.
>
> Which means this looks like it could be moved to CPU_ONLINE /
> CPU_DOWN_PREPARE which in turns means we could use dynamic IDs instead
> of those hardcoded ones since the LED subsystem does not depend on other
> components.
From the LED subsystem perspective I don't see any particular reason
for which it couldn't be accomplished from the ONLINE callbacks.
--
Best regards,
Jacek Anaszewski
prev parent reply other threads:[~2016-07-18 8:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20160713153219.128052238@linutronix.de>
2016-07-13 17:16 ` [patch V2 43/67] leds/trigger/cpu: Convert to hotplug state machine Anna-Maria Gleixner
2016-07-14 7:19 ` Jacek Anaszewski
2016-07-14 7:47 ` Ingo Molnar
2016-07-14 8:10 ` Jacek Anaszewski
2016-07-14 9:41 ` Peter Zijlstra
2016-07-14 11:23 ` Jacek Anaszewski
2016-07-14 11:33 ` Thomas Gleixner
2016-07-14 11:55 ` Jacek Anaszewski
2016-07-15 14:10 ` Sebastian Andrzej Siewior
2016-07-18 8:26 ` Jacek Anaszewski [this message]
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