From owner-freebsd-arch@FreeBSD.ORG Tue May 3 11:39:01 2011 Return-Path: Delivered-To: arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F1DEF106566C; Tue, 3 May 2011 11:39:01 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from mail.ebusiness-leidinger.de (mail.ebusiness-leidinger.de [217.11.53.44]) by mx1.freebsd.org (Postfix) with ESMTP id A336B8FC17; Tue, 3 May 2011 11:39:01 +0000 (UTC) Received: from outgoing.leidinger.net (p5B155A42.dip.t-dialin.net [91.21.90.66]) by mail.ebusiness-leidinger.de (Postfix) with ESMTPSA id E4525844017; Tue, 3 May 2011 13:38:47 +0200 (CEST) Received: from webmail.leidinger.net (webmail.Leidinger.net [IPv6:fd73:10c7:2053:1::2:102]) by outgoing.leidinger.net (Postfix) with ESMTP id 192DC11C4; Tue, 3 May 2011 13:38:45 +0200 (CEST) Received: (from www@localhost) by webmail.leidinger.net (8.14.4/8.13.8/Submit) id p43BciNr003835; Tue, 3 May 2011 13:38:44 +0200 (CEST) (envelope-from Alexander@Leidinger.net) Received: from pslux.ec.europa.eu (pslux.ec.europa.eu [158.169.9.14]) by webmail.leidinger.net (Horde Framework) with HTTP; Tue, 03 May 2011 13:38:44 +0200 Message-ID: <20110503133844.184523llr0156o9w@webmail.leidinger.net> Date: Tue, 03 May 2011 13:38:44 +0200 From: Alexander Leidinger To: John Baldwin References: <201105021537.19507.jhb@freebsd.org> <20110502195555.GC48734@deviant.kiev.zoral.com.ua> <201105021602.02668.jhb@freebsd.org> In-Reply-To: <201105021602.02668.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit User-Agent: Dynamic Internet Messaging Program (DIMP) H3 (1.1.6) X-EBL-MailScanner-Information: Please contact the ISP for more information X-EBL-MailScanner-ID: E4525844017.AECFB X-EBL-MailScanner: Found to be clean X-EBL-MailScanner-SpamCheck: not spam, spamhaus-ZEN, SpamAssassin (not cached, score=0, required 6, autolearn=disabled) X-EBL-MailScanner-From: alexander@leidinger.net X-EBL-MailScanner-Watermark: 1305027528.36203@JBEvHQeH/McqmNqpahOeYg X-EBL-Spam-Status: No Cc: Kostik Belousov , arch@freebsd.org Subject: Re: [PATCH] Add ktrace records for user page faults X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 May 2011 11:39:02 -0000 Quoting John Baldwin (from Mon, 2 May 2011 16:02:02 -0400): > It is true that it would be nice to have the exact faulting address, though > having page granularity has been sufficient for the few times I've actually > used the address itself (e.g. I could figure out which page of libstdc++ a > fault occurred on and narrow down from there as to which of the routines most > likely was executed given what the app was doing at the time). In my case > knowing how much time was spent handling a page fault has been useful. > > Would we have to push this logic out of vm_fault and into every > trap() routine > to get the original address? That would make the patch quite a bit bigger > (touching N MD files vs 1 MI file). dtrace is not a solution here (in general, not to the exact-address problem)? Bye, Alexander. -- I am looking for a honest man. -- Diogenes the Cynic http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137