From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752524AbaAQKYk (ORCPT ); Fri, 17 Jan 2014 05:24:40 -0500 Received: from mga02.intel.com ([134.134.136.20]:14771 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751331AbaAQKYh (ORCPT ); Fri, 17 Jan 2014 05:24:37 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,670,1384329600"; d="scan'208";a="460430576" Date: Fri, 17 Jan 2014 18:24:28 +0800 From: Fengguang Wu To: Davidlohr Bueso Cc: Stephen Rothwell , LKML Subject: [ipc] 5769cf63: LTP semget02 TFAILs Message-ID: <20140117102428.GC8751@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Davidlohr, We noticed LTP test failures ltp.msgget02.1.TFAIL ltp.semget02.2.TFAIL ltp.semget02.3.TFAIL and the first bad commit is commit 5769cf6355d87f63906b3e51887eff7017c39217 Author: Davidlohr Bueso AuthorDate: Wed Jan 15 16:56:01 2014 +1100 Commit: Stephen Rothwell CommitDate: Wed Jan 15 16:56:01 2014 +1100 ipc: share ids rwsem when possible in ipcget_public ... and rewrite the function. For scenarios where the key is found and we end up just doing different routinary checks, we can downgrade the ids->rwsem and share it among concurrent readers. These checks include the following, which are all safe to share the lock: ops->more_checks() >> sem_more_checks(), shm_more_checks() ipc_check_perms() >> ipcperms(),ops->associate() >> [lsm]_[ipctype]_associate() Signed-off-by: Davidlohr Bueso Cc: Aswin Chandramouleeswaran Cc: Rik van Riel Cc: Manfred Spraul Signed-off-by: Andrew Morton ipc/util.c | 60 +++++++++++++++++++++++++++++++++--------------------------- 1 file changed, 33 insertions(+), 27 deletions(-) Thanks, Fengguang