From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 17 Sep 2001 18:42:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 17 Sep 2001 18:41:05 -0400 Received: from tisch.mail.mindspring.net ([207.69.200.157]:9005 "EHLO tisch.mail.mindspring.net") by vger.kernel.org with ESMTP id ; Mon, 17 Sep 2001 18:40:50 -0400 Subject: Re: [SMP lock BUG?] Re: Feedback on preemptible kernel patch From: Robert Love To: Pavel Machek Cc: Manfred Spraul , Roger Larsson , linux-kernel@vger.kernel.org, nigel@nrg.org In-Reply-To: <20010914091558.A35@toy.ucw.cz> In-Reply-To: <000901c138bbe151270/mnt/sendme10411ac@local> <1000007070.836.14.camel@phantasy> <001a01c1390262c7f30/mnt/sendme10411ac@local> <20010914091558.A35@toy.ucw.cz> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Evolution/0.13.99+cvs.2001.09.17.07.08 (Preview Release) Date: 17 Sep 2001 18:41:46 -0400 Message-Id: <1000766512.12771.4.camel@phantasy> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2001-09-14 at 05:15, Pavel Machek wrote: > is it legal to kmap_atomic(a,b); kmap_atomic(c,d); kunmap_atomic(a,b); ? > If so, your patch may need some ounting.... ctx_sw_on and ctx_sw_off use a recursive spinlock, so the calls to kunmap_atomic won't drop the slock until the last call. -- Robert M. Love rml at ufl.edu rml at tech9.net