From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753607AbcCRWiZ (ORCPT ); Fri, 18 Mar 2016 18:38:25 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:57467 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570AbcCRWiW (ORCPT ); Fri, 18 Mar 2016 18:38:22 -0400 X-IBM-Helo: d23dlp02.au.ibm.com X-IBM-MailFrom: benh@au1.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-pm@vger.kernel.org Message-ID: <1458340635.3107.89.camel@au1.ibm.com> Subject: Re: [PATCH v8 3/6] cpufreq: powernv: Remove cpu_to_chip_id() from hot-path From: Benjamin Herrenschmidt Reply-To: benh@au1.ibm.com To: Michael Neuling , Shilpasri G Bhat , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Cc: ego@linux.vnet.ibm.com, linux-pm@vger.kernel.org, shreyas@linux.vnet.ibm.com, rjw@rjwysocki.net, pc@us.ibm.com, viresh.kumar@linaro.org, anton@samba.org Date: Sat, 19 Mar 2016 09:37:15 +1100 In-Reply-To: <1458273857.6622.75.camel@neuling.org> References: <1454442102-1229-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> <1454442102-1229-4-git-send-email-shilpa.bhat@linux.vnet.ibm.com> <1458273857.6622.75.camel@neuling.org> Organization: IBM Australia Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.1 (3.18.5.1-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16031822-0029-0000-0000-000044BD0120 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2016-03-18 at 15:04 +1100, Michael Neuling wrote: > >  static int nr_chips; > +static DEFINE_PER_CPU(unsigned int, chip_id); >   >  /* >   * Note: The set of pstates consists of contiguous integers, the > @@ -317,9 +318,7 @@ static void powernv_cpufreq_throttle_check(void > *data) >   >         pmsr = get_pmspr(SPRN_PMSR); >   > -       for (i = 0; i < nr_chips; i++) > -               if (chips[i].id == cpu_to_chip_id(cpu)) > -                       break; > +       i = this_cpu_read(chip_id); Except it's not a chip_id, so your patch confused me for a good 2mn ... Call it chip_idx maybe ? ie, index. Cheers, Ben. >         /* Check for Pmax Capping */ >         pmsr_pmax = (s8)PMSR_MAX(pmsr); > @@ -560,6 +559,7 @@ static int init_chip_info(void) >         for_each_possible_cpu(cpu) { >                 unsigned int id = cpu_to_chip_id(cpu); >   > +               per_cpu(chip_id, cpu) = nr_chips; >                 if (prev_chip_id != id) { >                         prev_chip_id = id; >                         chip[nr_chips++] = id; > _______________________________________________