Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752141AbWIXS5P (ORCPT ); Sun, 24 Sep 2006 14:57:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752144AbWIXS5P (ORCPT ); Sun, 24 Sep 2006 14:57:15 -0400 Received: from smtp.osdl.org ([65.172.181.4]:25031 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1752141AbWIXS5O (ORCPT ); Sun, 24 Sep 2006 14:57:14 -0400 Date: Sun, 24 Sep 2006 11:56:46 -0700 From: Andrew Morton To: dipankar@in.ibm.com Cc: linux-kernel@vger.kernel.org, Paul E McKenney , Ingo Molnar Subject: Re: [-mm PATCH] RCU: debug sleep check Message-Id: <20060924115646.6b5b6482.akpm@osdl.org> In-Reply-To: <20060924183509.GB22448@in.ibm.com> References: <20060923152957.GA13432@in.ibm.com> <20060924183509.GB22448@in.ibm.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 956 Lines: 30 On Mon, 25 Sep 2006 00:05:09 +0530 Dipankar Sarma wrote: > Add a debug check for rcu read-side critical section code calling > a function that might sleep which is illegal. The check is enabled only > if CONFIG_DEBUG_SPINLOCK_SLEEP is set. > Does this actually change anything? rcu_read_lock is preempt_disable(), and might_sleep() already triggers if called inside preempt_disable(). > -#define rcu_read_lock() __rcu_read_lock() > +#define rcu_read_lock() \ > + do { \ > + rcu_add_read_count(); \ > + __rcu_read_lock(); \ I don't have any __rcu_read_lock(). I guess this is against your to-be-resent RCU patches? > +DEFINE_PER_CPU(int, rcu_read_count); Can have static scope. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/