From: Tim Sander <tim@krieglstein.org>
To: Stanislav Meduna <stano@meduna.org>
Cc: "linux-rt-users@vger.kernel.org" <linux-rt-users@vger.kernel.org>
Subject: Re: i.MX28 milliseconds latencies, interrupts disabled in arch_cpu_idle?
Date: Sat, 19 Apr 2014 23:24:47 +0200 [thread overview]
Message-ID: <12490005.Mvd4Usk8IT@virgo> (raw)
In-Reply-To: <53516B19.6040702@meduna.org>
Hi Stanislav
Am Freitag, 18. April 2014, 20:12:41 schrieb Stanislav Meduna:
> On 18.04.2014 18:09, Tim Sander wrote:
> > Are you sure that this is not the cpu idle latency?
>
> Don't think so. However it is close to what I'd expect as an average
> idle time (capped up by periodic ticks @ 250 Hz = 4 ms).
Have you tried patching out the wfi in the idle loop? At least the i.mx35 does
some strange l2cache dance due to an hw bug. Patching out this whole stuff
helped a lot with latencys on an unloaded system.
Best regards
Tim
next prev parent reply other threads:[~2014-04-19 21:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-17 20:38 i.MX28 milliseconds latencies, interrupts disabled in arch_cpu_idle? Stanislav Meduna
2014-04-18 16:09 ` Tim Sander
2014-04-18 18:12 ` Stanislav Meduna
2014-04-18 22:21 ` Stanislav Meduna
2014-04-19 21:24 ` Tim Sander [this message]
2014-04-21 9:00 ` Stanislav Meduna
2014-04-19 10:36 ` Gilles Chanteperdrix
2014-04-21 9:11 ` Stanislav Meduna
2014-04-21 10:09 ` Gilles Chanteperdrix
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