Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261415AbVAaWuR (ORCPT ); Mon, 31 Jan 2005 17:50:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261416AbVAaWuR (ORCPT ); Mon, 31 Jan 2005 17:50:17 -0500 Received: from mail.joq.us ([67.65.12.105]:49542 "EHLO sulphur.joq.us") by vger.kernel.org with ESMTP id S261415AbVAaWtr (ORCPT ); Mon, 31 Jan 2005 17:49:47 -0500 To: Con Kolivas Cc: linux kernel , Andrew Morton , Ingo Molnar , Alexander Nyberg , Zwane Mwaikambo Subject: Re: [PATCH] sched - Implement priority and fifo support for SCHED_ISO References: <41F76746.5050801@kolivas.org> <87acqpjuoy.fsf@sulphur.joq.us> <41FE9582.7090003@kolivas.org> From: "Jack O'Quin" Date: Mon, 31 Jan 2005 16:51:29 -0600 In-Reply-To: <41FE9582.7090003@kolivas.org> (Con Kolivas's message of "Tue, 01 Feb 2005 07:30:58 +1100") Message-ID: <87651di55a.fsf@sulphur.joq.us> User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.4 (Corporate Culture, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3714 Lines: 113 Con Kolivas writes: > Sure enough I found the bug in less than 5 mins, and it would > definitely cause this terrible behaviour. > > A silly bracket transposition error on my part :P The corrected version works noticeably better, but still nowhere near as well as SCHED_FIFO. The first run had a cluster of really bad xruns. The second and third were much better, but still with numerous small xruns. http://www.joq.us/jack/benchmarks/sched-iso-fix/ With a compile running in the background it was a complete failure. Some kind of big xrun storm triggered a collapse on every attempt. http://www.joq.us/jack/benchmarks/sched-iso-fix+compile/ The summary statistics are mixed. The delay_max is noticeably better than before, but still much worse than SCHED_FIFO. But, the xruns are really bad news... http://www.joq.us/jack/benchmarks/.SUMMARY # sched-iso-fix Delay Maximum . . . . . . . . : 33894 usecs Delay Maximum . . . . . . . . : 745 usecs Delay Maximum . . . . . . . . : 341 usecs # sched-iso Delay Maximum . . . . . . . . : 21410 usecs Delay Maximum . . . . . . . . : 36830 usecs Delay Maximum . . . . . . . . : 4062 usecs # sched-fifo Delay Maximum . . . . . . . . : 347 usecs Delay Maximum . . . . . . . . : 277 usecs Delay Maximum . . . . . . . . : 246 usecs Delay Maximum . . . . . . . . : 199 usecs Delay Maximum . . . . . . . . : 261 usecs Delay Maximum . . . . . . . . : 305 usecs # sched-iso-fix+compile Delay Maximum . . . . . . . . : 14549 usecs Delay Maximum . . . . . . . . : 38961 usecs Delay Maximum . . . . . . . . : 26904 usecs # sched-iso+compile Delay Maximum . . . . . . . . : 98909 usecs Delay Maximum . . . . . . . . : 39414 usecs Delay Maximum . . . . . . . . : 40294 usecs Delay Maximum . . . . . . . . : 217192 usecs Delay Maximum . . . . . . . . : 156989 usecs # sched-fifo+compile Delay Maximum . . . . . . . . : 285 usecs Delay Maximum . . . . . . . . : 269 usecs Delay Maximum . . . . . . . . : 277 usecs Delay Maximum . . . . . . . . : 569 usecs Delay Maximum . . . . . . . . : 461 usecs Delay Maximum . . . . . . . . : 405 usecs Delay Maximum . . . . . . . . : 286 usecs Delay Maximum . . . . . . . . : 579 usecs # sched-iso-fix XRUN Count . . . . . . . . . : 26 XRUN Count . . . . . . . . . : 24 XRUN Count . . . . . . . . . : 17 # sched-iso XRUN Count . . . . . . . . . : 15 XRUN Count . . . . . . . . . : 17 XRUN Count . . . . . . . . . : 5 # sched-fifo XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 # sched-iso-fix+compile XRUN Count . . . . . . . . . : 22 XRUN Count . . . . . . . . . : 44 XRUN Count . . . . . . . . . : 39 # sched-iso+compile XRUN Count . . . . . . . . . : 44 XRUN Count . . . . . . . . . : 46 XRUN Count . . . . . . . . . : 45 XRUN Count . . . . . . . . . : 27 XRUN Count . . . . . . . . . : 101 # sched-fifo+compile XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 4 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 XRUN Count . . . . . . . . . : 0 -- joq - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/