From: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
To: Mohamed HAMZAOUI <requinham@gmail.com>
Cc: linux-can Mailing List <linux-can@vger.kernel.org>
Subject: Re: Problem of accuracy
Date: Thu, 05 Jul 2012 10:38:12 +0200 [thread overview]
Message-ID: <4FF55274.3030006@volkswagen.de> (raw)
In-Reply-To: <CABMxt4ijuTMYFYXx0n4AYBO6-=SRD0U3F4BTA2=rWE80Z4-yOA@mail.gmail.com>
On 05.07.2012 10:12, Mohamed HAMZAOUI wrote:
> Hi,
>
> i'm a new user of socketcan and, i cross compile can-utils for my craneboard
> card (a card with CAN).
> When i run cangen with 1 ms period, the period is not respected (1,407, 1.399,
> ...) !
>
> How can i fix this problem ?
>
> my can version in /proc/net/can/version is "rev 20090105 abi 8" and i'm on
> : Linux am3517-crane 2.6.32 #1 Mon Apr 23 00:13:28 CEST 2012 armv7l GNU/Linux
>
Hello Mohamed,
first please move to the new CAN mailing list (see CC) - and don't use
HTML-mails (text-only is better) ;-)
Regarding your problem:
Usually i get smaller derivations on my system - but your Linux box is
probably not very fast, so that you can see these scheduling influences with
cangen ...
cangen is a userpace app and therefore it is usually not that precise as
hrtimers inside the Linux kernel (if you don't use any realtime Linux).
But you may try the Broadcast-Manager to place a 'cyclic sending job' inside
the Linux kernel. See an example here:
http://svn.berlios.de/wsvn/socketcan/trunk/test/tst-bcm-cycle.c
Regards,
Oliver
next parent reply other threads:[~2012-07-05 8:38 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABMxt4ijuTMYFYXx0n4AYBO6-=SRD0U3F4BTA2=rWE80Z4-yOA@mail.gmail.com>
2012-07-05 8:38 ` Oliver Hartkopp [this message]
2012-07-07 10:02 ` [SocketCan] Problem of accuracy Mohamed HAMZAOUI
2012-07-07 10:32 ` Wolfgang Grandegger
2012-07-08 19:43 ` Mohamed HAMZAOUI
2012-07-08 20:13 ` Wolfgang Grandegger
2012-07-08 20:30 ` Mohamed HAMZAOUI
2012-07-09 7:18 ` Wolfgang Grandegger
2012-07-09 8:14 ` Mohamed HAMZAOUI
2012-07-09 8:20 ` Wolfgang Grandegger
2012-07-09 9:19 ` Mohamed HAMZAOUI
2012-07-09 9:22 ` Wolfgang Grandegger
[not found] ` <CABMxt4jnztXqAmLFcBnqp3001QXds1nX3xA2y_ka=xCNr0cjjA@mail.gmail.com>
[not found] ` <4FFAB09F.6090800@grandegger.com>
[not found] ` <CABMxt4jLRKz8xKNbH3Qa=P0k1aEjMsqmo2vArGDo2O1Wf0=wGQ@mail.gmail.com>
2012-07-09 11:26 ` Fwd: " Mohamed HAMZAOUI
2012-07-09 11:40 ` Wolfgang Grandegger
2012-07-09 11:57 ` Mohamed HAMZAOUI
2012-07-09 12:15 ` Wolfgang Grandegger
2012-07-09 13:19 ` Pavel Pisa
2012-07-09 14:29 ` Mohamed HAMZAOUI
2012-07-09 14:35 ` Mohamed HAMZAOUI
2012-07-09 14:40 ` Kurt Van Dijck
2012-07-09 14:57 ` Alexander Stein
2012-07-09 15:39 ` Mohamed HAMZAOUI
2012-07-09 17:08 ` Oliver Hartkopp
2012-07-09 20:50 ` Wolfgang Grandegger
2012-07-10 22:11 ` Mohamed HAMZAOUI
2012-07-11 12:35 ` Mohamed HAMZAOUI
2012-07-11 22:22 ` Wolfgang Grandegger
2012-07-11 22:19 ` Wolfgang Grandegger
2012-07-09 6:55 ` Kurt Van Dijck
[not found] ` <1341488146.2416.9.camel@slaptop>
2012-07-05 13:57 ` [Socketcan-users] back to back can frames Kurt Van Dijck
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