From: Philippe Gerum <rpm@xenomai.org>
To: Paul Janzen <pcj@xenomai.sez.to>, xenomai@xenomai.org
Subject: Re: [Xenomai] real-time guarantee issues on xenomai 2.6.2.1
Date: Thu, 07 Aug 2014 21:01:55 +0200 [thread overview]
Message-ID: <53E3CD23.5040909@xenomai.org> (raw)
In-Reply-To: <oqtx5om90q.fsf@merlin.sez.to>
On 08/07/2014 08:47 PM, Paul Janzen wrote:
> Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> writes:
>
>> And it also probably happens in some conditions only (with a large
>> number of Xenomai threads for instance)
>
> This is not quite correct. I experience large latencies (~1ms) during
> "watch cat /proc/xenomai/stat", just running xeno-test (stat lists two
> application tasks, two ROOTs and two IRQ-timers.)
>
> x64, SMP, Linux 3.4.6, ipipe-core-3.4.6-x86-4.patch, xenomai 242a6e4.
>
1 ms is definitely pathological. This cannot be related to
/proc/xenomai/stat or whatever vfile under /proc/xenomai, we would have
noticed.
This is more likely a I-pipe issue (3.4.6/x86 is outdated, although 1 ms
is really above usual issues), a kernel configuration issue (e.g.
CONFIG_CPU_FREQ, or other latency killer), or maybe a SMI problem. Or
maybe an issue induced by a graphic card driver if you happen to run
with a GUI.
--
Philippe.
next prev parent reply other threads:[~2014-08-07 19:01 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AE39D2A4-ECC3-481B-AF3B-8A67FA23D2BF@tuebingen.mpg.de>
[not found] ` <44BE6908-E639-421F-B556-E7B3871402CF@gmail.com>
2014-08-07 16:57 ` [Xenomai] real-time guarantee issues on xenomai 2.6.2.1 Alexander Herzog
2014-08-07 17:22 ` Gilles Chanteperdrix
2014-08-07 18:25 ` Philippe Gerum
2014-08-07 18:28 ` Gilles Chanteperdrix
2014-08-07 18:45 ` Philippe Gerum
2014-08-07 18:47 ` Paul Janzen
2014-08-07 19:01 ` Philippe Gerum [this message]
2014-08-07 19:16 ` Ludovic Righetti
2014-08-07 19:26 ` Philippe Gerum
2014-08-07 19:35 ` Ludovic Righetti
2014-08-07 19:44 ` Philippe Gerum
2014-08-07 19:56 ` Gilles Chanteperdrix
2014-08-08 6:59 ` Philippe Gerum
2014-08-08 12:05 ` Gilles Chanteperdrix
2014-08-07 20:47 ` Ludovic Righetti
2014-08-08 7:15 ` Philippe Gerum
2014-08-08 17:21 ` Paul Janzen
2014-08-08 17:25 ` Philippe Gerum
2014-08-08 18:27 ` Paul Janzen
2014-08-10 15:56 ` Gilles Chanteperdrix
2014-08-11 16:54 ` Paul Janzen
2014-08-11 17:25 ` Gilles Chanteperdrix
2014-08-11 17:43 ` Paul Janzen
2014-09-09 21:05 ` Gilles Chanteperdrix
2014-09-10 17:12 ` Nicholas Rotella
2014-08-11 23:25 ` Ludovic Righetti
2014-08-07 19:26 ` Gilles Chanteperdrix
2014-03-04 19:55 Alexander Herzog
2014-03-05 8:02 ` Gilles Chanteperdrix
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