Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934852Ab3FSOaz (ORCPT ); Wed, 19 Jun 2013 10:30:55 -0400 Received: from a10-63.smtp-out.amazonses.com ([54.240.10.63]:36590 "EHLO a10-63.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934417Ab3FSOay (ORCPT ); Wed, 19 Jun 2013 10:30:54 -0400 X-Greylist: delayed 706 seconds by postgrey-1.27 at vger.kernel.org; Wed, 19 Jun 2013 10:30:54 EDT Date: Wed, 19 Jun 2013 14:19:06 +0000 From: Christoph Lameter To: "Paul E. McKenney" cc: Frederic Weisbecker , Steven Rostedt , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Li Zhong , Borislav Petkov , Kevin Hilman , Mats Liljegren , LKML Subject: Re: [ANNOUNCE] Full dynticks selftests 0.0.1 In-Reply-To: <20130618181733.GS5146@linux.vnet.ibm.com> Message-ID: <0000013f5ccd9d66-616fef8f-7cf1-45ec-bd20-b1fed9264cbe-000000@email.amazonses.com> References: <20130612151915.GD5332@somewhere> <0000013f57a89d51-89f08a58-65d0-41f5-aaaa-b31d60c72a8e-000000@email.amazonses.com> <20130618151520.GP5146@linux.vnet.ibm.com> <20130618162256.GH17619@somewhere.redhat.com> <20130618181733.GS5146@linux.vnet.ibm.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SES-Outgoing: 2013.06.19-54.240.10.63 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 993 Lines: 19 On Tue, 18 Jun 2013, Paul E. McKenney wrote: > +online to handle timekeeping tasks in order to ensure that system > +calls like gettimeofday() returns accurate values on adaptive-tick CPUs. > +(This is not an issue for CONFIG_NO_HZ_IDLE=y because there are no running > +user processes to observe slight drifts in clock rate.) Therefore, the > +boot CPU is prohibited from entering adaptive-ticks mode. Specifying a > +"nohz_full=" mask that includes the boot CPU will result in a boot-time > +error message, and the boot CPU will be removed from the mask. Note that > +this means that your system must have at least two CPUs in order for > +CONFIG_NO_HZ_FULL=y to do anything for you. These are some important point here. Very good. Thanks. -- 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/