From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754697AbbDTJap (ORCPT ); Mon, 20 Apr 2015 05:30:45 -0400 Received: from e18.ny.us.ibm.com ([129.33.205.208]:37659 "EHLO e18.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753891AbbDTJam (ORCPT ); Mon, 20 Apr 2015 05:30:42 -0400 Message-ID: <5534C739.1080600@linux.vnet.ibm.com> Date: Mon, 20 Apr 2015 15:00:33 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Thomas Gleixner , LKML CC: Peter Zijlstra , Ingo Molnar , Viresh Kumar , Marcelo Tosatti , Frederic Weisbecker , John Stultz Subject: Re: [patch 08/39] hrtimer: Make offset update smarter References: <20150414203303.702062272@linutronix.de> <20150414203501.132820245@linutronix.de> In-Reply-To: <20150414203501.132820245@linutronix.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15042009-0033-0000-0000-0000006A02F3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/15/2015 02:38 AM, Thomas Gleixner wrote: >>On every tick/hrtimer interrupt we update the offset variables of the >>clock bases. That's silly because these offsets change very seldom. >> >>Add a sequence counter to the time keeping code which keeps track of >>the offset updates (clock_was_set()). Have a sequence cache in the >>hrtimer cpu bases to evaluate whether the offsets must be updated or >>not. This allows us later to avoid pointless cacheline pollution. >> >>Signed-off-by: Thomas Gleixner >>Cc: John Stultz Reviewed-by: Preeti U Murthy