From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <462DF8CD.6090304@domain.hid> Date: Tue, 24 Apr 2007 14:32:13 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <45F68258.5040603@domain.hid> <460B7FDF.8030100@domain.hid> <460BECFD.2030003@domain.hid> <460C0C7D.7000001@domain.hid> <17964.64208.463335.611234@domain.hid> <462DC874.20303@domain.hid> <462DE13C.7030305@domain.hid> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigEF7FB555DF70DE25CCD5706C" Sender: jan.kiszka@domain.hid Subject: Re: [Xenomai-help] Latencies due to RT-Socket-CAN register accesses List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: roland Tollenaar Cc: Xenomai-help@domain.hid This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigEF7FB555DF70DE25CCD5706C Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable roland Tollenaar wrote: >> > I am aware of this. For the current machine I will stick to this. >> > >> >> Then don't complain. :) > Yes sir! > :) > Not complaining really, I think and I hope that the latency of 30us > average will do nicely for me. Just curious actually. >=20 >> > to be give worse latencies than much slower machines. Are the 2 >> > interrupts causing the latency? >> >> Those two increase the latency of code in timed tasks, for sure. The >> question is if your measurement on the slower machine also included th= is >> scenario (timer event + 2 IRQs in a row). This definitely doesn't happ= en >> often, and maybe timing on the slower box makes it less likely. Or the= re >> is one potential IRQ source more on your fast box (e.g. due to IRQ >> sharing on the slower one). >> >> You see, RT system design on the edge (ie. when hunting a few 10 us) i= s >> tricky and not easily portable from box X to box Y. >=20 > Its not possible to determine which IRQ's are responsible for this > from the trace I presume? >=20 echo 1 > /proc/ipipe/trace/verbose Then look at the "User Val." reported at "common_interrupt" (see also [1]= ). Jan [1] http://www.xenomai.org/index.php/I-pipe:Tracer --------------enigEF7FB555DF70DE25CCD5706C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGLfjQniDOoMHTA+kRAlvHAJ470vDaZ7z3a1FDJL6jxevPXQIz1QCcDHqW /Pbn8D6QvL88wZpYzQg6unc= =hT19 -----END PGP SIGNATURE----- --------------enigEF7FB555DF70DE25CCD5706C--