From: Pradyumna Sampath <pradysam@gmail.com>
To: "M. Koehrer" <mathias_koehrer@arcor.de>
Cc: linux-rt-users@vger.kernel.org, rachana.rao@in.abb.com
Subject: Re: mq_timedrecieve timeout accuracy
Date: Wed, 24 Mar 2010 14:37:23 +0100 [thread overview]
Message-ID: <6d09081c1003240637w28ee6861tfcef4c7876ef3e40@mail.gmail.com> (raw)
In-Reply-To: <8226231.1269436934345.JavaMail.ngmail@webmail10.arcor-online.net>
Hi,
On Wed, Mar 24, 2010 at 2:22 PM, M. Koehrer <mathias_koehrer@arcor.de> wrote:
> Does it help to run the posix threads with realtime priority by calling
> pthread_setschedparam() with SCHED_FIFO and a suitable priority?
> As fas as I understand your code, the threads run with standard (non realtime
> priority).
Yes. I tried this with a chrt -f 99. But I still end up getting those
large deviations.
John, mq_timedrecieve takes abstime. Isnt it supposed to be
CLOCK_REALTIME ? Anyway, I tried with MONOTONIC .. mq_timedrecieve
doesnt block on that.
I was just looking at some code in the kernel. linux/ipc/mqueue.c
+442. This line says:
time = schedule_timeout(timeout);
Maybe this is why produces a timeout that is inaccurate. Shouldnt it
be schedule_hrtimeout ?
regards
/prady
--
http://www.prady.in
next prev parent reply other threads:[~2010-03-24 13:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-24 12:27 mq_timedrecieve timeout accuracy Pradyumna Sampath
2010-03-24 13:12 ` John Kacur
2010-03-24 13:21 ` Sujit K M
2010-03-24 13:22 ` M. Koehrer
2010-03-24 13:37 ` Pradyumna Sampath [this message]
2010-03-24 13:45 ` Sujit K M
2010-03-24 13:47 ` Pradyumna Sampath
2010-03-24 14:03 ` Pradyumna Sampath
2010-03-24 15:46 ` [PATCH] " Pradyumna Sampath
2010-03-29 15:08 ` [PATCH] " Carsten Emde
2010-03-30 7:41 ` Pradyumna Sampath
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