From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272444AbTHEFBo (ORCPT ); Tue, 5 Aug 2003 01:01:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272445AbTHEFBo (ORCPT ); Tue, 5 Aug 2003 01:01:44 -0400 Received: from holomorphy.com ([66.224.33.161]:2690 "EHLO holomorphy") by vger.kernel.org with ESMTP id S272444AbTHEFBn (ORCPT ); Tue, 5 Aug 2003 01:01:43 -0400 Date: Mon, 4 Aug 2003 22:02:50 -0700 From: William Lee Irwin III To: Valdis.Kletnieks@vt.edu Cc: Nick Piggin , Con Kolivas , linux kernel mailing list , Andrew Morton Subject: Re: [PATCH] O11int for interactivity Message-ID: <20030805050250.GP32488@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Valdis.Kletnieks@vt.edu, Nick Piggin , Con Kolivas , linux kernel mailing list , Andrew Morton References: <200308042106.51676.m.c.p@wolk-project.de> <20030804195335.GK32488@holomorphy.com> <3F2F00B0.9050804@cyberone.com.au> <20030805024103.GM32488@holomorphy.com> <3F2F1F80.7060207@cyberone.com.au> <20030805031341.GN32488@holomorphy.com> <3F2F231C.3030901@cyberone.com.au> <20030805033119.GO32488@holomorphy.com> <3F2F26BA.3060904@cyberone.com.au> <200308050454.h754sBqM004950@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200308050454.h754sBqM004950@turing-police.cc.vt.edu> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 05 Aug 2003 13:38:34 +1000, Nick Piggin said: >> Of course some minimum read _latency_ would be required: this >> could actually be done easily with strace come to think of it. >> Maybe some xmms mapped memory is being swapped out? But that >> would be more of a VM problem. On Tue, Aug 05, 2003 at 12:54:10AM -0400, Valdis.Kletnieks@vt.edu wrote: > I was seeing some CPU-related pauses, but once Con's work got to O7 or so, > those disappeared. I'm *quite* convinced that the remaining glitches > are VM related, mostly because every glitch seems to be associated with > an increase in the 'pswpout' field in /proc/vmstat (yes, I tested > with stuff like "for (;;) do cat /proc/vmstat; sleep 1 done;". Could I get logs of the stuff? On Tue, Aug 05, 2003 at 12:54:10AM -0400, Valdis.Kletnieks@vt.edu wrote: > The *odd* part is that the pgpgin, pgpgout, and pswpin numbers do > *NOT* seem to be correlated. High I/O loads from read/write don't > seem to cause a problem - untarring the Linux distro won't do it, > running badblocks won't do it. But if somebody has to swap out, all > hell breaks loose... Is the swapfile/partition on the same disk as the music? Is the disk IDE? On Tue, Aug 05, 2003 at 12:54:10AM -0400, Valdis.Kletnieks@vt.edu wrote: > Hmm.. looking at mm/page_io.c, it seems swap_writepage() calls > get_swap_bio with GFP_NOIO, while readdpage() uses GFP_KERNEL. I > wonder if that GFP_NOIO is causing ugliness - that's really > __GFP_WAIT, and the comments in bio_alloc() are pretty clear that it > can block. And remember we're not getting into this code unless > we're already under memory pressure.... > (And if somebody tells me how to instrument a -test2-mm4 kernel so I > can tell if I'm on crack or not, I'll happily do so....) Well, sleepometer is around, but probably needs merging. -- wli