From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: One of these things (CONFIG_HZ) is not like the others..
Date: Tue, 22 Jan 2013 13:52:57 -0800 [thread overview]
Message-ID: <20130122215257.GU22517@atomide.com> (raw)
In-Reply-To: <50FEE175.90504@linaro.org>
* John Stultz <john.stultz@linaro.org> [130122 11:02]:
>
> Correct, with HRT, we actually trigger the HZ-frequency timer tick
> from an hrtimer (which expires based on the system time driven by
> the clocksource). Thus even if there is a theoretical error between
> the ideal HZ and what the hardware can do, that error will not
> propagate forward.
If there's no cumulative error, sounds like the way to go is to select
HRT for ARM multiplatform builds and set the HZ to 100 then.
Regards,
Tony
WARNING: multiple messages have this Message-ID (diff)
From: Tony Lindgren <tony@atomide.com>
To: John Stultz <john.stultz@linaro.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>,
Santosh Shilimkar <santosh.shilimkar@ti.com>,
Arnd Bergmann <arnd@arndb.de>,
Peter Zijlstra <peterz@infradead.org>,
Matt Sealey <matt@genesi-usa.com>,
LKML <linux-kernel@vger.kernel.org>, Ben Dooks <ben@simtec.co.uk>,
Ingo Molnar <mingo@redhat.com>,
Linux ARM Kernel ML <linux-arm-kernel@lists.infradead.org>
Subject: Re: One of these things (CONFIG_HZ) is not like the others..
Date: Tue, 22 Jan 2013 13:52:57 -0800 [thread overview]
Message-ID: <20130122215257.GU22517@atomide.com> (raw)
In-Reply-To: <50FEE175.90504@linaro.org>
* John Stultz <john.stultz@linaro.org> [130122 11:02]:
>
> Correct, with HRT, we actually trigger the HZ-frequency timer tick
> from an hrtimer (which expires based on the system time driven by
> the clocksource). Thus even if there is a theoretical error between
> the ideal HZ and what the hardware can do, that error will not
> propagate forward.
If there's no cumulative error, sounds like the way to go is to select
HRT for ARM multiplatform builds and set the HZ to 100 then.
Regards,
Tony
next prev parent reply other threads:[~2013-01-22 21:52 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-21 20:01 One of these things (CONFIG_HZ) is not like the others Matt Sealey
2013-01-21 20:01 ` Matt Sealey
2013-01-21 20:41 ` Arnd Bergmann
2013-01-21 20:41 ` Arnd Bergmann
2013-01-21 21:00 ` John Stultz
2013-01-21 21:00 ` John Stultz
2013-01-21 21:12 ` Russell King - ARM Linux
2013-01-21 21:12 ` Russell King - ARM Linux
2013-01-21 22:18 ` John Stultz
2013-01-21 22:18 ` John Stultz
2013-01-21 22:44 ` Russell King - ARM Linux
2013-01-21 22:44 ` Russell King - ARM Linux
2013-01-22 8:27 ` Arnd Bergmann
2013-01-22 8:27 ` Arnd Bergmann
2013-01-21 22:20 ` Matt Sealey
2013-01-21 22:20 ` Matt Sealey
2013-01-21 22:42 ` Russell King - ARM Linux
2013-01-21 22:42 ` Russell King - ARM Linux
2013-01-21 23:23 ` Matt Sealey
2013-01-21 23:23 ` Matt Sealey
2013-01-21 23:49 ` Russell King - ARM Linux
2013-01-21 23:49 ` Russell King - ARM Linux
2013-01-22 0:09 ` Matt Sealey
2013-01-22 0:09 ` Matt Sealey
2013-01-22 0:26 ` Matt Sealey
2013-01-22 0:26 ` Matt Sealey
2013-01-21 21:14 ` Matt Sealey
2013-01-21 21:14 ` Matt Sealey
2013-01-21 22:36 ` John Stultz
2013-01-21 22:36 ` John Stultz
2013-01-21 22:49 ` Russell King - ARM Linux
2013-01-21 22:49 ` Russell King - ARM Linux
2013-01-21 22:54 ` Matt Sealey
2013-01-21 22:54 ` Matt Sealey
2013-01-21 23:13 ` Russell King - ARM Linux
2013-01-21 23:13 ` Russell King - ARM Linux
2013-01-21 23:30 ` Matt Sealey
2013-01-21 23:30 ` Matt Sealey
2013-01-22 0:02 ` Russell King - ARM Linux
2013-01-22 0:02 ` Russell King - ARM Linux
2013-01-22 0:38 ` John Stultz
2013-01-22 0:38 ` John Stultz
2013-01-22 0:51 ` John Stultz
2013-01-22 0:51 ` John Stultz
2013-01-22 1:06 ` Matt Sealey
2013-01-22 1:06 ` Matt Sealey
2013-01-22 1:18 ` Russell King - ARM Linux
2013-01-22 1:18 ` Russell King - ARM Linux
2013-01-22 1:56 ` Matt Sealey
2013-01-22 1:56 ` Matt Sealey
2013-01-22 1:31 ` John Stultz
2013-01-22 1:31 ` John Stultz
2013-01-22 2:10 ` Matt Sealey
2013-01-22 2:10 ` Matt Sealey
2013-01-31 21:31 ` Thomas Gleixner
2013-01-31 21:31 ` Thomas Gleixner
2013-01-21 21:02 ` Matt Sealey
2013-01-21 21:02 ` Matt Sealey
2013-01-21 22:30 ` Arnd Bergmann
2013-01-21 22:30 ` Arnd Bergmann
2013-01-21 22:45 ` Russell King - ARM Linux
2013-01-21 22:45 ` Russell King - ARM Linux
2013-01-21 23:01 ` Matt Sealey
2013-01-21 23:01 ` Matt Sealey
2013-01-21 21:03 ` Russell King - ARM Linux
2013-01-21 21:03 ` Russell King - ARM Linux
2013-01-21 23:23 ` Tony Lindgren
2013-01-21 23:23 ` Tony Lindgren
2013-01-22 6:23 ` Santosh Shilimkar
2013-01-22 6:23 ` Santosh Shilimkar
2013-01-22 9:31 ` Arnd Bergmann
2013-01-22 9:31 ` Arnd Bergmann
2013-01-22 10:14 ` Santosh Shilimkar
2013-01-22 10:14 ` Santosh Shilimkar
2013-01-22 14:51 ` Russell King - ARM Linux
2013-01-22 14:51 ` Russell King - ARM Linux
2013-01-22 15:05 ` Santosh Shilimkar
2013-01-22 15:05 ` Santosh Shilimkar
2013-01-28 6:08 ` Santosh Shilimkar
2013-01-28 6:08 ` Santosh Shilimkar
2013-01-29 0:01 ` John Stultz
2013-01-29 0:01 ` John Stultz
2013-01-29 6:43 ` Santosh Shilimkar
2013-01-29 6:43 ` Santosh Shilimkar
2013-01-29 10:06 ` Russell King - ARM Linux
2013-01-29 10:06 ` Russell King - ARM Linux
2013-01-29 18:43 ` John Stultz
2013-01-29 18:43 ` John Stultz
2013-01-22 17:31 ` Arnd Bergmann
2013-01-22 17:31 ` Arnd Bergmann
2013-01-22 18:59 ` John Stultz
2013-01-22 18:59 ` John Stultz
2013-01-22 21:52 ` Tony Lindgren [this message]
2013-01-22 21:52 ` Tony Lindgren
2013-01-23 5:18 ` Santosh Shilimkar
2013-01-23 5:18 ` Santosh Shilimkar
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