From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pan Xinhui Subject: Re: [PATCH V2] acpi-cpufreq: replace per_cpu with driver_data of policy Date: Thu, 09 Jul 2015 09:28:30 +0800 Message-ID: <559DCE3E.8050105@intel.com> References: <559BC96E.8020804@intel.com> <20150707143443.GT14598@linux> <12074796.mAD950pclu@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga01.intel.com ([192.55.52.88]:30732 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752409AbbGIBbF (ORCPT ); Wed, 8 Jul 2015 21:31:05 -0400 In-Reply-To: <12074796.mAD950pclu@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" , Viresh Kumar Cc: "linux-kernel@vger.kernel.org" , linux-pm@vger.kernel.org, "mnipxh@163.com" , "yanmin_zhang@linux.intel.com" hi, Rafael thanks for your kind reply. :) On 2015=E5=B9=B407=E6=9C=8809=E6=97=A5 08:20, Rafael J. Wysocki wrote: > On Tuesday, July 07, 2015 08:04:43 PM Viresh Kumar wrote: >> On 07-07-15, 20:43, Pan Xinhui wrote: >>> >>> Drivers can store their internal per-policy information in >>> policy->driver_data, lets use it. >>> >>> we have benefits after this replacing. >>> 1) memory saving. >>> 2) policy is shared by several cpus, per_cpu seems not correct. usi= ng >>> *driver_data* is more reasonable. >>> 3) fix a memory leak in acpi_cpufreq_cpu_exit. as policy->cpu might >>> change during cpu hotplug. So sometimes we cant't free *data*, use >>> *driver_data* to fix it. >>> 4) fix a zero return value of get_cur_freq_on_cpu. Only per_cpu of >>> policy->cpu is set to *data*, if we try to get cpufreq on other cpu= s, we >>> get zero instead of correct values. Use *driver_data* to fix it. >>> >>> Signed-off-by: Pan Xinhui >>> --- >>> Changes from V1: >>> codes style fix, comments update >>> move cpufreq_cpu_put(policy) after we get *driver_data* >>> --- >>> drivers/cpufreq/acpi-cpufreq.c | 40 ++++++++++++++++++++++--------= ---------- >>> 1 file changed, 22 insertions(+), 18 deletions(-) >> >> Acked-by: Viresh Kumar >=20 > OK >=20 > Does it fix any recent regressions or is it just an old bug? >=20 This patch achieve old bug fix and codes improvements. In past days, po= licy has no field *driver_data*, So acpi-cpufreq driver has to use per_cpu to store some extra information.= But it did not take good care of every scenarios. Now cpufreq core makes awesome effort to store more per-policy informat= ion in policy. We can make use of this feature. So I cook this patch. :) I am preparing two patches for other two issues in acpi-cpufreq driver = based on this patch. I will fix them step by step. :) thanks xinhui > Rafael >=20