From owner-freebsd-current@FreeBSD.ORG Wed Nov 3 16:42:26 2010 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5771D1065670 for ; Wed, 3 Nov 2010 16:42:26 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 719508FC14 for ; Wed, 3 Nov 2010 16:42:25 +0000 (UTC) Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua [212.40.38.101]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id SAA11441; Wed, 03 Nov 2010 18:42:23 +0200 (EET) (envelope-from avg@icyb.net.ua) Message-ID: <4CD190EF.5080600@icyb.net.ua> Date: Wed, 03 Nov 2010 18:42:23 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.11) Gecko/20101021 Lightning/1.0b2 Thunderbird/3.1.5 MIME-Version: 1.0 To: mdf@FreeBSD.org References: In-Reply-To: X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-current@FreeBSD.org Subject: Re: MTX_DEF versus MTX_SPIN X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Nov 2010 16:42:26 -0000 on 03/11/2010 18:27 mdf@FreeBSD.org said the following: > It's not clear to me from the man pages (perhaps I didn't look at the > right one?) in which environments I need a spinlock. For example, I > wouldn't think it's safe to use a MTX_DEF in a hard interrupt handler > (i.e one that was registered with BUS_SETUP_INTR), but I see some code > lying around here that does it and nothing I'm aware of has broken. Such a handler runs in an interrupt thread. The "harder" interrupt handler is called interrupt filter in FreeBSD terminology. I think that it was formerly known as fast interrupt. -- Andriy Gapon