From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266847AbUGLOZ4 (ORCPT ); Mon, 12 Jul 2004 10:25:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266848AbUGLOZ4 (ORCPT ); Mon, 12 Jul 2004 10:25:56 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.105]:45198 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S266847AbUGLOYa (ORCPT ); Mon, 12 Jul 2004 10:24:30 -0400 Date: Mon, 12 Jul 2004 07:24:20 -0700 From: "Martin J. Bligh" To: Con Kolivas , linux-kernel@vger.kernel.org cc: akpm@osdl.org Subject: Re: [PATCH] Instrumenting high latency Message-ID: <75270000.1089642258@[10.10.2.4]> In-Reply-To: References: X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Because of the recent discussion about latency in the kernel I asked > William Lee Irwin III to help create some instrumentation to determine > where in the kernel there were still sustained periods of non-preemptible > code. He hacked together this simple patch which times periods according > to the preempt count. Hopefully we can use this patch in the advice of > Linus to avoid the "mental masturbation" at guessing where latency is > and track down real problem areas. Is this much different from Rick's schedstat's work, which was itself based on some earlier patches by Bill? I'd hate to end up with two sets of patches, and schedstats seemed pretty comprehensive to me. He's on vacation, but his stuff is here, if you want to take a look: http://eaglet.rain.com/rick/linux/schedstats/