From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <47E397AE.2010009@domain.hid> Date: Fri, 21 Mar 2008 12:10:38 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <2ff1a98a0803180723i17d6d6e1p619b9c8948b6e542@domain.hid> <18401.32383.382321.517340@domain.hid> <2ff1a98a0803210354g40137eeds72eb742142856cd@domain.hid> In-Reply-To: <2ff1a98a0803210354g40137eeds72eb742142856cd@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig22772BA851289C0955E839D9" Sender: jan.kiszka@domain.hid Subject: Re: [Xenomai-help] Handling irq List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix , Bosko Radivojevic Cc: xenomai-help This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig22772BA851289C0955E839D9 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Gilles Chanteperdrix wrote: > On Fri, Mar 21, 2008 at 11:50 AM, Bosko Radivojevic > wrote: >> I have much better results using rtdm_lock_get_irqsave and >> rtdm_lock_put_irqrestore. I hope this is the "appropriate method" of >> doing it :) >> >> Thanks! >=20 > Shutting interrupts off for long periods of time is not a good idea: > - it does not scale well, since it does not work for more than one task= ; > - it kills the precision of timers by delaying the timer interrupt. > And I am sure we can find many more drawbacks. - it only reduces the probability of your problem, it doe not eliminate it completely You can still be interrupted right after task wakeup, before=20 rtdm_lock_get_irqsave. And there is still the possibility to be delayed=20 by interrupts BEFORE your task is even triggered. If you cannot live with this conceptual jitter (which you'll find on any = RTOS with more than one job running), you have to do ahead-of-time=20 scheduling with busy waiting until the actual release date. That will=20 mean disabling IRQs for a really long time + burning a lot of CPU power. = Kind of last resort, not generally recommended. Jan --------------enig22772BA851289C0955E839D9 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 iD8DBQFH45euniDOoMHTA+kRAuu/AJ42LSVP7WX9qQQnQkDx4IMB5U0cnwCggO36 xwpj0tE6xoIdSjIq1V6F7Wg= =w+/d -----END PGP SIGNATURE----- --------------enig22772BA851289C0955E839D9--