From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266263AbUHRMxX (ORCPT ); Wed, 18 Aug 2004 08:53:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266262AbUHRMwr (ORCPT ); Wed, 18 Aug 2004 08:52:47 -0400 Received: from mail.gmx.net ([213.165.64.20]:2498 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S266175AbUHRMuy (ORCPT ); Wed, 18 Aug 2004 08:50:54 -0400 X-Authenticated: #4399952 Date: Wed, 18 Aug 2004 15:01:48 +0200 From: Florian Schmidt To: Ingo Molnar Cc: Lee Revell , Thomas Charbonnel , linux-kernel , Felipe Alfaro Solana Subject: Re: [patch] voluntary-preempt-2.6.8.1-P3 Message-Id: <20040818150148.4d2c56ec@mango.fruits.de> In-Reply-To: <20040818122703.GA17301@elte.hu> References: <1092627691.867.150.camel@krustophenia.net> <20040816034618.GA13063@elte.hu> <1092628493.810.3.camel@krustophenia.net> <20040816040515.GA13665@elte.hu> <1092654819.5057.18.camel@localhost> <20040816113131.GA30527@elte.hu> <20040816120933.GA4211@elte.hu> <1092716644.876.1.camel@krustophenia.net> <20040817080512.GA1649@elte.hu> <20040818141231.4bd5ff9d@mango.fruits.de> <20040818122703.GA17301@elte.hu> X-Mailer: Sylpheed-Claws 0.9.12 (GTK+ 1.2.10; i386-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Aug 2004 14:27:03 +0200 Ingo Molnar wrote: > > * Florian Schmidt wrote: > > > Hi, it applied against 2.6.8.1 with some offsets and some buzz [?]. > > Well anyways it compiled fine and the copy_page_range latency is > > gone.. Now i also see the extracty entropy thing, too.. > > could you try the attached patch that changes SHA_CODE_SIZE to 3 - > does this reduce the latency caused by extract_entropy? will do.. > > > Btw: one question: at one point in time the IRQ handlers were in the > > SCHED_FIFO scheduling class. Why has this changed? > > so that they dont starve the audio threads by default - the audio IRQ > has to get another priority anyway. Maybe we could try a default > SCHED_FIFO prio lower than the typical rt_priority of jackd - e.g. 30? Oh, upon rereading the chrt manpage i found out why i failed to set them to SCHED_FIFO manually. So it was my error. I thought the scheduling of the IRQ handlers was not changable at runtime. Thus my question to make them SCHED_FIFO by default. Well, i still think they should be SCHED_FIFO by default, so no user process that is not itself SCHED_FIFO can starve them [X11 was able to starve mouse irq's on my system with the defualt IRQ handlers running SCHED_OTHER FWIW]. To make starving of user-SCHED_FIFO processes unprobably maybe use a default static prio of 0. Afaik jackd uses priorities > 0 for its audio threads when runing SCHED_FIFO anyways.. But since the user will have to tweak his IRQ handlers manually anyways [set soundcard irq higher prio than the rest, etc..], it doesn't really make a difference. Flo -- Palimm Palimm! http://affenbande.org/~tapas/