From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 9 Jun 2001 15:34:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 9 Jun 2001 15:34:13 -0400 Received: from t2.redhat.com ([199.183.24.243]:56822 "EHLO passion.cambridge.redhat.com") by vger.kernel.org with ESMTP id ; Sat, 9 Jun 2001 15:34:02 -0400 X-Mailer: exmh version 2.3 01/15/2001 with nmh-1.0.4 From: David Woodhouse X-Accept-Language: en_GB In-Reply-To: In-Reply-To: To: Linus Torvalds Cc: Alexander Viro , linux-kernel@vger.kernel.org, Dawson Engler Subject: Re: [CHECKER] a couple potential deadlocks in 2.4.5-ac8 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 09 Jun 2001 20:33:01 +0100 Message-ID: <19317.992115181@redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org torvalds@transmeta.com said: > Good point. Spinlocks (with the exception of read-read locks, of > course) and semaphores will deadlock on recursive use, while the BKL > has this "process usage counter" recursion protection. Obtaining a read lock twice can deadlock too, can't it? A B read_lock() write_lock() ...sleeps... read_lock() ...sleeps... Or do we not make new readers sleep if there's a writer waiting? -- dwmw2