From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <459C190E.3080601@domain.hid> Date: Wed, 03 Jan 2007 21:58:54 +0100 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Xenomai-help] parallelport module for measuring external interrupt latency References: <459B6DAD.4030406@domain.hid> <459B7C6C.9030401@domain.hid> <459B8382.7060508@domain.hid> <459B8A19.2060809@domain.hid> <459C13C5.9010007@domain.hid> In-Reply-To: <459C13C5.9010007@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig32488AA84F42E3053CAF4041" Sender: jan.kiszka@domain.hid List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig32488AA84F42E3053CAF4041 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Markus Franke wrote: > Jan Kiszka wrote: >> Even if the notification is not time-critical, you first have to get o= ut >> of the Xenomai context in a sane manner. rtdm_nrtsig may help if you >> don't want to use the RT scheduler for user task wakeup. >=20 > OK. Thank you for the hint with rtdm_nrtsig_*. The kernel-module works = now. >=20 > But I have still a problem when generating interrupts with a high > frequency, let's say 100us. Then I get large latencies in the range of > 1,5 seconds. Can you see any reason for this. An intervall of 1ms works= > without any problems and the latencies reach maybe 13us in worst case. Unless you have a very slow hardware that already overruns at 10 KHz (rather unlikely) or some SMI-related latencies bite you (see TROUBLESHOOTING) - I have no clue right now. Do standard Xenomai tests show similar abnormal latencies? If no, you may want to try the ipipe latency tracer: enable it in the kernel hacking section and put a xntrace_user_freeze() in your application right after when it detected some extreme latency. See the wiki for more details on the tracer. Jan --------------enig32488AA84F42E3053CAF4041 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFnBkSniDOoMHTA+kRAjV+AJ0f5XQQ20RjJ0Wy1Ck3ZXZ8PGkJBwCghLkX mi/fIuWUjEkKy5X3H4QfnNA= =bHVF -----END PGP SIGNATURE----- --------------enig32488AA84F42E3053CAF4041--