From owner-freebsd-firewire@FreeBSD.ORG Tue Dec 16 06:03:20 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 A2E431065670; Tue, 16 Dec 2008 06:03:20 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 5E1708FC1F; Tue, 16 Dec 2008 06:03:20 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.2/8.14.1) with ESMTP id mBG61UKQ048412; Mon, 15 Dec 2008 23:01:30 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Mon, 15 Dec 2008 23:01:30 -0700 (MST) Message-Id: <20081215.230130.74702477.imp@bsdimp.com> To: freebsd@sopwith.solgatos.com From: Warner Losh In-Reply-To: <200812150330.DAA27074@sopwith.solgatos.com> References: <200812150330.DAA27074@sopwith.solgatos.com> X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-firewire@FreeBSD.org, freebsd-drivers@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, 16 Dec 2008 06:03:20 -0000 > I found the source of this problem. When a firewire bus resets, > the firewire driver prints a few lines to the console, > using printf(9) and device_printf(9). I suspect that these are > running at splfw aka splimp, locking out other i/o. This can't be the case. There's no SPL involved at all. Maybe removing the printfs causes an interrupt to be serviced faster, resulting in what appears to be better performance... > Commenting out the *printf() calls fixes the problem, but that > isn't a good solution. > > Would changing the *printf() calls to log(9) calls be safe? > ("safe" meaning other i/o doesn't get locked out) > > Ah, for the good old days when 19200 baud seemed fast... > _______________________________________________ > freebsd-drivers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-drivers > To unsubscribe, send any mail to "freebsd-drivers-unsubscribe@freebsd.org" > >