From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8648 invoked by alias); 16 Jan 2006 15:11:15 -0000 Received: (qmail 8638 invoked by uid 22791); 16 Jan 2006 15:11:14 -0000 X-Spam-Check-By: sourceware.org Received: from omr2.networksolutionsemail.com (HELO mail.networksolutionsemail.com) (205.178.146.52) by sourceware.org (qpsmtpd/0.31) with SMTP; Mon, 16 Jan 2006 15:11:13 +0000 Received: (qmail 29614 invoked from network); 16 Jan 2006 15:11:11 -0000 Received: from unknown (HELO rivatek.dnsalias.net) (67.52.40.201) by omr2.mgt.bos.netsol.com with SMTP; 16 Jan 2006 15:11:11 -0000 Received: by rivatek.dnsalias.net (Postfix, from userid 501) id D49003CAC0; Mon, 16 Jan 2006 09:14:51 -0600 (CST) To: ecos-discuss@ecos.sourceware.org From: Grant Edwards In-Reply-To: <43CB5897.3090300@zurich.ibm.com> References: <74C9525D67A5FF4791614FDB06593BB1028532@mail.systech.com> <43CB5897.3090300@zurich.ibm.com> Date: Mon, 16 Jan 2006 15:11:00 -0000 Message-Id: <20060116151451.D49003CAC0@rivatek.dnsalias.net> Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: [ECOS] Re: DSR Scheduling Problem X-SW-Source: 2006-01/txt/msg00127.txt.bz2 In gmane.os.ecos.general, you wrote: >>>I still think that FIFO queuing of the DSRs is better than >>>LIFO queuing, because in the absence of any DSR priority >>>information, the best that can be done is temporal priority >>>(ie FIFO). >> >>That happens to work for your application, but I don't see how >>you can say that FIFO is best in the general case. >> > hmm...i think jay has a point here: we are apparently loosing temporal > ordering True. > --- so even if a system would be capable of handling the load > if the DSRs were executed in the order the associated ISRs occurred, > with the current LIFO implementation it fails --- as demonstrated by jay. I don't see how he's demonstrated that at all. If you need to run 150ms of DSRs in a 100ms time period, you're not going to be able to run them all by re-ordering them. Jay didn't demonstrate that changing the order made all his DSRs run as often as they needed to. >>I still maintain that your application is either broken or you >>don't have enough CPU. If one interrupts source requires so >>much DSR time that others can't run, then there is simply >>something wrong. You seem to prefer a tx underrun error to an >>rx overrun error. I guarantee you're going to get one or the >>other. On the systems I work on, either is equally fatal, so >>it is not the case that FIFO is better than LIFO. Both work >>equally well. >> >> > hmm...apparently jay is seeing neither of your predicted results since > he switched to FIFO... How do we know he's not getting tx FIFO underruns? -- Grant Edwards grante Yow! .. I see TOILET at SEATS... visi.com -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss