From: viresh.kumar@linaro.org (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: schedule_timeout sleeps too long after dividing CPU frequency
Date: Thu, 14 May 2015 17:24:56 +0530 [thread overview]
Message-ID: <20150514115456.GB23999@linux> (raw)
In-Reply-To: <5554858A.9010207@free.fr>
On 14-05-15, 13:22, Mason wrote:
> I didn't /literally/ take a stop-watch to verify it was EXACTLY
> 9 seconds, but I was staring at the prompt, and it /felt/ like
> 9 seconds. And the 54 second case felt like a minute.
:)
> I'm using a 27 MHz crystal as clocksource. This is independent
> of the CPU frequency. However, I'm using the ARM TWD as the
> system's clockevent source, and the TWD's clock is tied to
> the CPU clock (PERIPHCLK = CPUCLK / 2 on this SoC).
The only (very straight forward) problem is that we aren't propagating
the freq update to clockevents core and you need to debug a bit there.
Also I wanted to see the source of your print message:
[ 19.650454] NEW RATE=9250000
[ 19.653644] NEW RATE=9250000
What's this rate ? Old/new ? Because you are atleast printing the old
rate here, and the function by default gets the new rate.
> I'm wondering if there's another standard clockevent source
> I could try (it would be great if it supported high-resolution
> timers).
I hope you have some platform general-purpose-timers.
--
viresh
next prev parent reply other threads:[~2015-05-14 11:54 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-12 14:32 schedule_timeout sleeps too long after dividing CPU frequency Mason
2015-05-12 14:46 ` Viresh Kumar
2015-05-12 15:14 ` Mason
2015-05-12 15:50 ` Russell King - ARM Linux
2015-05-12 16:14 ` Mason
2015-05-13 16:51 ` Mason
2015-05-14 2:13 ` Viresh Kumar
2015-05-14 11:22 ` Mason
2015-05-14 11:54 ` Viresh Kumar [this message]
2015-05-14 13:06 ` Mason
2015-05-14 13:53 ` Russell King - ARM Linux
2015-05-14 14:51 ` Mason
2015-05-14 13:59 ` Viresh Kumar
2015-05-14 14:38 ` Viresh Kumar
2015-05-14 14:42 ` Russell King - ARM Linux
2015-05-15 9:29 ` Mason
2015-05-15 9:51 ` Russell King - ARM Linux
2015-05-15 10:01 ` Viresh Kumar
2015-05-15 10:36 ` Mason
2015-05-15 11:58 ` Russell King - ARM Linux
2015-05-15 12:45 ` Mason
2015-05-15 13:15 ` Russell King - ARM Linux
2015-05-15 13:58 ` Mason
2015-05-15 18:35 ` Mason
2015-05-18 11:24 ` Mason
2015-05-18 11:54 ` Russell King - ARM Linux
2015-05-20 16:21 ` Mason
2015-05-20 18:50 ` Arnd Bergmann
2015-05-20 19:34 ` Mason
2015-05-20 20:14 ` Russell King - ARM Linux
2015-05-20 20:41 ` Mason
2015-05-20 20:52 ` Arnd Bergmann
2015-05-20 21:56 ` Mason
2015-05-20 22:18 ` Arnd Bergmann
2015-05-21 12:35 ` Mason
2015-05-20 23:14 ` Russell King - ARM Linux
2015-05-21 9:56 ` Mason
2015-05-21 10:20 ` Russell King - ARM Linux
2015-05-14 14:48 ` Mason
2015-05-15 4:16 ` Viresh Kumar
2015-05-15 5:07 ` Viresh Kumar
2015-05-15 9:00 ` Russell King - ARM Linux
2015-05-15 9:21 ` Mason
2015-05-15 10:11 ` Mason
2015-05-12 15:23 ` Russell King - ARM Linux
2015-05-12 16:03 ` Mason
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