Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751486Ab3HTPmG (ORCPT ); Tue, 20 Aug 2013 11:42:06 -0400 Received: from mga14.intel.com ([143.182.124.37]:6912 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751194Ab3HTPmF (ORCPT ); Tue, 20 Aug 2013 11:42:05 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,921,1367996400"; d="scan'208";a="349055136" Message-ID: <52138E46.1030007@linux.intel.com> Date: Tue, 20 Aug 2013 08:41:58 -0700 From: Arjan van de Ven User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Frederic Weisbecker CC: Peter Zijlstra , "Rafael J. Wysocki" , Viresh Kumar , =?ISO-8859-1?Q?Fernando_Luis_?= =?ISO-8859-1?Q?V=E1zquez_Cao?= , Oleg Nesterov , Ingo Molnar , Thomas Gleixner , LKML , Tetsuo Handa , Andrew Morton Subject: Re: [PATCH 2/4] nohz: Synchronize sleep time stats with seqlock References: <1376667753-29014-3-git-send-email-fweisbec@gmail.com> <20130816160201.GA31682@redhat.com> <20130816162056.GE24210@somewhere> <20130816162654.GA453@redhat.com> <20130816164626.GH24210@somewhere> <20130819111026.GE24092@twins.programming.kicks-ass.net> <521313D8.9080500@lab.ntt.co.jp> <20130820084405.GC3258@twins.programming.kicks-ass.net> <20130820152910.GB17441@somewhere> <52138C5E.4060705@linux.intel.com> <20130820153524.GC17441@somewhere> In-Reply-To: <20130820153524.GC17441@somewhere> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1372 Lines: 34 On 8/20/2013 8:35 AM, Frederic Weisbecker wrote: > On Tue, Aug 20, 2013 at 08:33:50AM -0700, Arjan van de Ven wrote: >> On 8/20/2013 8:29 AM, Frederic Weisbecker wrote: >> >>>> >>>> Of course, if we can get away with completely removing all of that >>>> (which I think Arjan suggested was a real possibility) then that would >>>> be ever so much better still :-) >>> >>> Would be lovely. But I don't know much about cpufreq, I hope somebody who's >>> familiar with that code can handle this. Then once there are no more users >>> of get_cpu_iowait_sleep_time() I can simply zap and clean the tick/time related >>> code. >> >> it's just doing the "idle = 100 - busy% - iowait%" calculation. >> (with the later part only for Intel cpus iirc) >> >> in a perfect world the scheduler would be doing that calculation in the first place ;-) >> >> removing the later part will impact performance some on specific workloads, >> but most Intel cpus that this applies to should not be using cpufreq anymore >> anyway. > > Are there other users than intel? > http://lxr.linux.no/linux+v3.10.7/drivers/cpufreq/cpufreq_ondemand.c#L69 nope -- 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/