Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753422Ab3EPRzd (ORCPT ); Thu, 16 May 2013 13:55:33 -0400 Received: from mga09.intel.com ([134.134.136.24]:64622 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751643Ab3EPRzc (ORCPT ); Thu, 16 May 2013 13:55:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,685,1363158000"; d="scan'208";a="338441944" From: Andi Kleen To: Davidlohr Bueso Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, riel@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 04/11] ipc: move locking out of ipcctl_pre_down_nolock References: <1368666490-29055-1-git-send-email-davidlohr.bueso@hp.com> <1368666490-29055-5-git-send-email-davidlohr.bueso@hp.com> Date: Thu, 16 May 2013 10:55:28 -0700 In-Reply-To: <1368666490-29055-5-git-send-email-davidlohr.bueso@hp.com> (Davidlohr Bueso's message of "Wed, 15 May 2013 18:08:03 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 641 Lines: 18 Davidlohr Bueso writes: > This function currently acquires both the rw_mutex and the rcu lock on > successful lookups, leaving the callers to explicitly unlock them, creating > another two level locking situation. Note that the rcu read lock is not a real lock, so it doesn't have the usual ordering problems. -Andi -- ak@linux.intel.com -- Speaking for myself only -- 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/