From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 16 May 2002 11:51:03 -0300 (BRT) From: Rik van Riel Subject: Re: [RFC][PATCH] iowait statistics In-Reply-To: <51039.193.133.92.239.1021542563.squirrel@lbbrown.homeip.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Leigh Brown Cc: linux-mm@kvack.org List-ID: On Thu, 16 May 2002, Leigh Brown wrote: > I've tried this patch against Red Hat's 2.4.18 kernel on my laptop, and > patched top to display the results. It certainly seems to be working > correctly running a few little contrived tests. Cool, could you please post the patch to top so other people can enjoy it too ? ;) (I'm leaving for holidays this evening and am too lazy to patch top myself now ;)) > CPU states: 0.5% user, 3.5% system, 0.0% nice, 0.0% idle, 95.8% wait > > which is what I'd expect based on my experience. However, Doing a > "raw /dev/raw/raw1 /dev/hdc" followed by a "dd if=/dev/raw/raw1 ..." > gives this sort of result: > > CPU states: 0.3% user, 8.9% system, 0.0% nice, 77.2% idle, 13.3% wait > > I'm not sure if that can be explained by the way the raw I/O stuff works, > or because I'm running it against 2.4. Anyway, overall it's looking good. Most likely the patch forgets to increment nr_iowait_tasks in some raw IO code path... regards, Rik -- Bravely reimplemented by the knights who say "NIH". http://www.surriel.com/ http://distro.conectiva.com/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/