Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 18 Dec 2001 13:55:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 18 Dec 2001 13:54:14 -0500 Received: from h24-64-71-161.cg.shawcable.net ([24.64.71.161]:43761 "EHLO lynx.adilger.int") by vger.kernel.org with ESMTP id ; Tue, 18 Dec 2001 13:53:02 -0500 Date: Tue, 18 Dec 2001 11:52:43 -0700 From: Andreas Dilger To: Doug Ledford Cc: Kernel Mailing List Subject: Re: Scheduler ( was: Just a second ) ... Message-ID: <20011218115243.Y855@lynx.no> Mail-Followup-To: Doug Ledford , Kernel Mailing List In-Reply-To:

<20011218105459.X855@lynx.no> <3C1F8A9E.3050409@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.4i In-Reply-To: <3C1F8A9E.3050409@redhat.com>; from dledford@redhat.com on Tue, Dec 18, 2001 at 01:27:42PM -0500 X-GPG-Key: 1024D/0D35BED6 X-GPG-Fingerprint: 7A37 5D79 BF1B CECA D44F 8A29 A488 39F5 0D35 BED6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Dec 18, 2001 13:27 -0500, Doug Ledford wrote: > Andreas Dilger wrote: > > Yes, esd is an interrupt hog, it seems. When reading this thread, I > > checked, and sure enough I was getting 190 interrupts/sec on the > > sound card while not playing any sound. I killed esd (which I don't > > use anyways), and interrupts went to 0/sec when not playing sound. > > Still at 190/sec when using mpg123 on my ymfpci (Yamaha YMF744B DS-1S) > > sound card. > > Weel, evidently esd and artsd both do this (well, I assume esd does now, it > didn't do this in the past). Basically, they both transmit silence over the > sound chip when nothing else is going on. So even though you don't hear > anything, the same sound output DMA is taking place. That avoids things > like nasty pops when you start up the sound hardware for a beep and that > sort of thing. Hmm, I _do_ notice a pop when the sound hardware is first initialized at boot time, but not when mpg123 starts/stops (without esd running) so I personally don't get any benefit from "the sound of silence". That said, asside from the 190 interrupts/sec from esd, it doesn't appear to use any measurable CPU time by itself. > Context switches per second not playing any sound: 8300 - 8800 > Context switches per second playing an MP3: 9200 - 9900 Hmm, something seems very strange there. On an idle system, I get about 100 context switches/sec, and about 150/sec when playing sound (up to 400/sec when moving the mouse between windows). 9000 cswitches/sec is _very_ high. This is with a text-only player which has screen output (other than the ID3 info from the currently played song). Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/ - 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/