From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933895AbbDJPb2 (ORCPT ); Fri, 10 Apr 2015 11:31:28 -0400 Received: from mail-am1on0057.outbound.protection.outlook.com ([157.56.112.57]:17082 "EHLO emea01-am1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932419AbbDJPb0 (ORCPT ); Fri, 10 Apr 2015 11:31:26 -0400 Authentication-Results: vger.kernel.org; dkim=none (message not signed) header.d=none; Message-ID: <5527ECC1.4090903@ezchip.com> Date: Fri, 10 Apr 2015 11:31:13 -0400 From: Chris Metcalf User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Frederic Weisbecker CC: "Peter Zijlstra (Intel)" , "Paul E. McKenney" , "Rafael J. Wysocki" , Martin Schwidefsky , Ingo Molnar , Subject: Re: [PATCH v6 1/2] nohz: add tick_nohz_full_add_cpus_to() and _remove_cpus_from() APIs References: <20150409174218.GT21418@twins.programming.kicks-ass.net> <1428602506-16753-1-git-send-email-cmetcalf@ezchip.com> <20150410013443.GE18314@lerouge> In-Reply-To: <20150410013443.GE18314@lerouge> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [12.216.194.146] X-ClientProxiedBy: BLUPR11CA0070.namprd11.prod.outlook.com (10.141.30.38) To AM2PR02MB0769.eurprd02.prod.outlook.com (25.163.146.154) X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:AM2PR02MB0769;UriScan:;BCL:0;PCL:0;RULEID:;SRVR:AM2PR02MB0883; X-Microsoft-Antispam-PRVS: X-Forefront-Antispam-Report: BMV:1;SFV:NSPM;SFS:(10009020)(6009001)(6049001)(377454003)(479174004)(41574002)(24454002)(51704005)(36756003)(59896002)(33656002)(46102003)(54356999)(87266999)(77156002)(62966003)(87976001)(66066001)(1411001)(65956001)(64126003)(65816999)(110136001)(83506001)(47776003)(122386002)(42186005)(50986999)(2950100001)(80316001)(86362001)(19580395003)(92566002)(76176999)(15975445007)(23746002)(77096005)(50466002)(18886065003);DIR:OUT;SFP:1101;SCL:1;SRVR:AM2PR02MB0769;H:[10.7.0.41];FPR:;SPF:None;MLV:sfv;LANG:en; X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(5005006)(5002010);SRVR:AM2PR02MB0769;BCL:0;PCL:0;RULEID:;SRVR:AM2PR02MB0769; X-Forefront-PRVS: 054231DC40 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Apr 2015 15:31:22.4008 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM2PR02MB0769 X-OriginatorOrg: ezchip.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2015 09:34 PM, Frederic Weisbecker wrote: > On Thu, Apr 09, 2015 at 02:01:45PM -0400, Chris Metcalf wrote: >> --- a/include/linux/tick.h >> +++ b/include/linux/tick.h >> @@ -186,6 +186,18 @@ static inline bool tick_nohz_full_cpu(int cpu) >> return cpumask_test_cpu(cpu, tick_nohz_full_mask); >> } >> >> +static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) > Or tick_nohz_full_affine() ? I'd vote no to that, I think - the first problem I see is that it doesn't make very clear that it modifies the argument, which is the problem Peter Z has been having from the beginning with some suggestions. The second problem is that it sounds like it might be setting the argument unconditionally to the nohz_full set, when in fact it's doing a cpumask_or() to increase the set of cpus further. > + /* nohz_full won't take effect without isolating the cpus. */ > + tick_nohz_full_remove_cpus_from(cpu_isolated_map); > This should be the other one I guess. > Thanks! Now off to do some actual testing before sending the next patchset :-) -- Chris Metcalf, EZChip Semiconductor http://www.ezchip.com