Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752783AbaBYErL (ORCPT ); Mon, 24 Feb 2014 23:47:11 -0500 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:34894 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558AbaBYErJ (ORCPT ); Mon, 24 Feb 2014 23:47:09 -0500 Message-ID: <530C2045.1090704@linux.vnet.ibm.com> Date: Tue, 25 Feb 2014 12:47:01 +0800 From: Michael wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Sasha Levin , Ingo Molnar , LKML Subject: Re: sched: hang in migrate_swap References: <5304F32A.4040907@oracle.com> <5305856F.3000109@linux.vnet.ibm.com> <53078241.3060201@oracle.com> <53080122.609@linux.vnet.ibm.com> <530ABB44.5000601@oracle.com> <530AD653.3000808@linux.vnet.ibm.com> <20140224071028.GW9987@twins.programming.kicks-ass.net> <530B1B80.4000307@linux.vnet.ibm.com> <20140224121218.GR15586@twins.programming.kicks-ass.net> <20140224131025.GG3104@twins.programming.kicks-ass.net> In-Reply-To: <20140224131025.GG3104@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14022504-8256-0000-0000-00000BA1A2DB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/24/2014 09:10 PM, Peter Zijlstra wrote: > On Mon, Feb 24, 2014 at 01:12:18PM +0100, Peter Zijlstra wrote: >> + if (p) { >> + if (unlikely(p == RETRY_TASK)) >> + goto again; > > We could even make that: unlikely(p & 1), I think most CPUs can encode > that far better than the full pointer immediate. Agree, unless odd-align stuff appeared... Regards, Michael Wang > -- > 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/ > -- 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/