From: khilman@deeprootsystems•com (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] arm: sched: stop sched_clock() during suspend
Date: Tue, 23 Oct 2012 07:17:33 -0700 [thread overview]
Message-ID: <87a9vdclxe.fsf@deeprootsystems.com> (raw)
In-Reply-To: <20121023092231.GE28061@n2100.arm.linux.org.uk> (Russell King's message of "Tue, 23 Oct 2012 10:22:31 +0100")
Russell King - ARM Linux <linux@arm•linux.org.uk> writes:
> On Tue, Oct 23, 2012 at 12:28:32AM +0200, Linus Walleij wrote:
>> On Mon, Oct 22, 2012 at 7:05 PM, Kevin Hilman
>> <khilman@deeprootsystems•com> wrote:
>>
>> > However, in light of RT throttling, this a correctness issue for process
>> > accounting, so I agree that this should be done for all platforms
>> > instead of providing an optional 'needs suspend' version of the API,
>> > even though it means printk times no longer reflect time spent
>> > suspended.
>>
>> Maybe we should get printk() to use the best clocksource
>> instead.
>>
>> The reason AFAICT that printk() is using sched_clock() is that
>> it's supposed to be fast. But now it seems that it's not going
>> to return what printk() needs anymore.
>
> No, printk() does not need this. You think it does, but it doesn't. What
> we have is a difference between ARM and x86, and this difference is breaking
> the scheduler.
>
> The fact that the printk timestamp increments while suspended is a bug. It
> doesn't on x86.
Russell, I agree that it's a bug, but does it qualify as a something
you're willing to take for v3.7-rc?
For OMAP, we need to know if this will go for v3.7 or not because
there's a regression in the OMAP I2C driver, and if this doesn't go in,
we'll need to revert something in the I2C driver until it does.
Thanks,
Kevin
next prev parent reply other threads:[~2012-10-23 14:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-22 11:54 [PATCH] arm: sched: stop sched_clock() during suspend Felipe Balbi
2012-10-22 12:07 ` Felipe Balbi
2012-10-22 17:05 ` Kevin Hilman
2012-10-22 22:28 ` Linus Walleij
2012-10-23 9:22 ` Russell King - ARM Linux
2012-10-23 14:17 ` Kevin Hilman [this message]
2012-10-23 16:03 ` Russell King - ARM Linux
2012-10-23 17:24 ` Felipe Balbi
2012-10-23 5:57 ` [PATCH v2] " Felipe Balbi
2012-10-23 14:14 ` Kevin Hilman
2012-10-23 10:11 ` [PATCH] " Linus Walleij
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=87a9vdclxe.fsf@deeprootsystems.com \
--to=khilman@deeprootsystems$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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