From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752691AbaAGSNg (ORCPT ); Tue, 7 Jan 2014 13:13:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26759 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752049AbaAGSN3 (ORCPT ); Tue, 7 Jan 2014 13:13:29 -0500 Date: Tue, 7 Jan 2014 19:12:58 +0100 From: Oleg Nesterov To: Andrew Morton , "Paul E. McKenney" Cc: Al Viro , Dipankar Sarma , Eric Dumazet , linux-kernel@vger.kernel.org Subject: [PATCH 0/2] rcu_dereference_check_fdtable fix/cleanups Message-ID: <20140107181258.GA29288@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. I tried to audit the users of thread_group_empty() (we need to change it) and found rcu_my_thread_group_empty() which looks wrong. The patches look simple, but I am not sure it is fine to use rcu_lock_acquire() directly. Perhaps it makes sense to add a new helper? Note that we have more users which take rcu lock only to shut up lockdep. Please review. And I am a bit confused. Perhaps rcu_lock_acquire() should depend on CONFIG_PROVE_RCU, not on CONFIG_DEBUG_LOCK_ALLOC? We only need rcu_lock_map/etc for rcu_lockdep_assert(). Oleg. fs/file.c | 24 +++++++++++------------- include/linux/fdtable.h | 19 +++++++++++++------ include/linux/rcupdate.h | 2 -- kernel/rcu/update.c | 11 ----------- 4 files changed, 24 insertions(+), 32 deletions(-)