From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262837AbUGMCzK (ORCPT ); Mon, 12 Jul 2004 22:55:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262450AbUGMCzK (ORCPT ); Mon, 12 Jul 2004 22:55:10 -0400 Received: from holomorphy.com ([207.189.100.168]:42386 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S262837AbUGMCzF (ORCPT ); Mon, 12 Jul 2004 22:55:05 -0400 Date: Mon, 12 Jul 2004 19:55:02 -0700 From: William Lee Irwin III To: Gabriel Devenyi Cc: ck@vds.kolivas.org, linux-kernel@vger.kernel.org Subject: Re: [ck] Re: Preempt Threshold Measurements Message-ID: <20040713025502.GR21066@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Gabriel Devenyi , ck@vds.kolivas.org, linux-kernel@vger.kernel.org References: <200407121943.25196.devenyga@mcmaster.ca> <20040713024051.GQ21066@holomorphy.com> <200407122248.50377.devenyga@mcmaster.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200407122248.50377.devenyga@mcmaster.ca> User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 12, 2004 at 10:48:50PM -0400, Gabriel Devenyi wrote: > Well I'm not particularly educated in kernel internals yet, here's some > reports from the system when its running. > 6ms non-preemptible critical section violated 4 ms preempt threshold starting > at do_munmap+0xd2/0x140 and ending at do_munmap+0xeb/0x140 > [] do_munmap+0xeb/0x140 > [] dec_preempt_count+0x110/0x120 > [] do_munmap+0xeb/0x140 > [] sys_munmap+0x3f/0x60 > [] sysenter_past_esp+0x52/0x71 Looks like ZAP_BLOCK_SIZE may be too large for you. Lowering that some may "help" this. It's probably harmless, but try lowering that to half of whatever it is now, or maybe 64*PAGE_SIZE. It may be worthwhile to restructure how the preemption points are done in unmap_vmas() so we don't end up in some kind of tuning nightmare. -- wli