Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757592AbZLNQAQ (ORCPT ); Mon, 14 Dec 2009 11:00:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757581AbZLNQAO (ORCPT ); Mon, 14 Dec 2009 11:00:14 -0500 Received: from casper.infradead.org ([85.118.1.10]:35336 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757555AbZLNQAM (ORCPT ); Mon, 14 Dec 2009 11:00:12 -0500 Date: Mon, 14 Dec 2009 08:02:01 -0800 From: Arjan van de Ven To: Oliver Neukum Cc: Frederic Weisbecker , Ingo Molnar , Linus Torvalds , Thomas Gleixner , Alan Cox , Andrew Morton , Greg KH , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [GIT PATCH] TTY patches for 2.6.33-git Message-ID: <20091214080201.466a8998@infradead.org> In-Reply-To: <200912141139.48115.oliver@neukum.org> References: <20091212101032.GB25286@elte.hu> <20091213191606.GB7297@nowhere> <20091213213015.653307b5@infradead.org> <200912141139.48115.oliver@neukum.org> Organization: Intel X-Mailer: Claws Mail 3.7.3 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1148 Lines: 29 On Mon, 14 Dec 2009 11:39:48 +0100 Oliver Neukum wrote: > Am Montag, 14. Dezember 2009 06:30:15 schrieb Arjan van de Ven: > > > We have the bkl tracepoints for that, attaching an example below, > > > blkdev_get/bkldev_put is among the highest consumer for me. > > > > we have a trace, but not a number that anyone can just pull out > > without having to go through great lengths to set stuff up... (esp > > to capture a boot)... > > Adding a counter always to the lock_kernel function should be fine > > instead... > > But don't we need to know how long it is held? If you just count > you'll make code that drops it while it can look bad. I think/hope we're well past that. At this point, just the act of taking it at all is bad. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/