From owner-freebsd-firewire@FreeBSD.ORG Tue Dec 23 03:21:51 2008 Return-Path: Delivered-To: freebsd-firewire@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 78AE3106564A; Tue, 23 Dec 2008 03:21:51 +0000 (UTC) (envelope-from sbruno@miralink.com) Received: from plato.miralink.com (mail.miralink.com [70.103.185.20]) by mx1.freebsd.org (Postfix) with ESMTP id 4C3E48FC19; Tue, 23 Dec 2008 03:21:51 +0000 (UTC) (envelope-from sbruno@miralink.com) Received: from localhost (localhost.localdomain [127.0.0.1]) by plato.miralink.com (Postfix) with ESMTP id 8843F1A9135; Mon, 22 Dec 2008 20:21:49 -0800 (PST) X-Virus-Scanned: amavisd-new at X-Spam-Flag: NO X-Spam-Score: -4.399 X-Spam-Level: X-Spam-Status: No, score=-4.399 tagged_above=-10 required=6.6 tests=[ALL_TRUSTED=-1.8, BAYES_00=-2.599] Received: from plato.miralink.com ([127.0.0.1]) by localhost (plato.miralink.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id G5l4E3C5Raht; Mon, 22 Dec 2008 20:21:49 -0800 (PST) Received: from [10.47.1.6] (vpn.office.miralink.com [10.0.0.5]) by plato.miralink.com (Postfix) with ESMTP id E27541A90C8; Mon, 22 Dec 2008 20:21:48 -0800 (PST) Message-ID: <4950594D.50208@miralink.com> Date: Mon, 22 Dec 2008 19:21:49 -0800 From: Sean Bruno User-Agent: Thunderbird 2.0.0.18 (X11/20081119) MIME-Version: 1.0 To: Dieter References: <200812210524.FAA02070@sopwith.solgatos.com> In-Reply-To: <200812210524.FAA02070@sopwith.solgatos.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-firewire@freebsd.org, bug-followup@freebsd.org Subject: Re: kern/118093: firewire bus reset hogs CPU, causing data to be lost X-BeenThere: freebsd-firewire@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Firewire support in FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Dec 2008 03:21:51 -0000 Dieter wrote: > In message <494DAEB1.1070909@miralink.com>, Sean Bruno writes: > > >> I setup my system to execute a bus reset every 1 second, simultaneously, >> I started copying a large >> file onto the system see if anything would happen. >> >> I saw no change to copy speed reported by SCP during the entire >> transaction. I also see no change >> to the system load while this is occurring. >> > > Does your system have a RS-232 console or VGA console? > The problem might be specific to RS-232. > > I have both. I disabled my serial console to test, no change when using the VGA console only. >> This seems indicative of "something else" going on. >> > > Any idea what this "something else" might be? > > Does anyone have a clue why my spl calls are returning 0 ? > > I confirmed that spl's are complete no-ops since rel 5. So, you want to ignore them as they are just markers now where locking should be implemented. I went back in your original submission and I can see a significant drop in I/O when resetting the F/W bus. If I have the following running: dd if=/dev/zero of=/dev/ad6 bs=64k Then I see about 64MB/S normally. When I reset any firewire bus, I see the throughput drop as reported by iostat by a significant amount(2-4 MB/s). I am assuming that the firewire driver is holding a very heavy lock here that is cascading down to the printf(). At least, that would be my ASSumption. :) I will continue to poke around. You are not crazy Dieter. Sean