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: Tue, 07 Jul 2015 20:49:06 +0800 Message-ID: <559BCAC2.8020908@intel.com> References: <559BC96E.8020804@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga11.intel.com ([192.55.52.93]:8170 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757138AbbGGMvj (ORCPT ); Tue, 7 Jul 2015 08:51:39 -0400 In-Reply-To: <559BC96E.8020804@intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "linux-kernel@vger.kernel.org" , linux-pm@vger.kernel.org Cc: rjw@rjwysocki.net, viresh.kumar@linaro.org, "mnipxh@163.com" , "yanmin_zhang@linux.intel.com" hi, all thanks for reviewing. any comments or advices are welcome :) I am OOO tomorrow, so response may arrive later. thanks xinhui On 2015=E5=B9=B407=E6=9C=8807=E6=97=A5 20:43, Pan Xinhui wrote: >=20 > Drivers can store their internal per-policy information in > policy->driver_data, lets use it. >=20 > we have benefits after this replacing. > 1) memory saving. > 2) policy is shared by several cpus, per_cpu seems not correct. using > *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 cpus,= we > get zero instead of correct values. Use *driver_data* to fix it. >=20 > 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(-) >=20 > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cp= ufreq.c > index 0136dfc..e7fcaa6 100644 > --- a/drivers/cpufreq/acpi-cpufreq.c > +++ b/drivers/cpufreq/acpi-cpufreq.c > @@ -72,8 +72,6 @@ struct acpi_cpufreq_data { > cpumask_var_t freqdomain_cpus; > }; > =20 > -static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data); > - > /* acpi_perf_data is a pointer to percpu data. */ > static struct acpi_processor_performance __percpu *acpi_perf_data; > =20 > @@ -144,7 +142,7 @@ static int _store_boost(int val) > =20 > static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, c= har *buf) > { > - struct acpi_cpufreq_data *data =3D per_cpu(acfreq_data, policy->cpu= ); > + struct acpi_cpufreq_data *data =3D policy->driver_data; > =20 > return cpufreq_show_cpus(data->freqdomain_cpus, buf); > } > @@ -327,7 +325,8 @@ static void drv_write(struct drv_cmd *cmd) > put_cpu(); > } > =20 > -static u32 get_cur_val(const struct cpumask *mask) > +static u32 > +get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *da= ta) > { > struct acpi_processor_performance *perf; > struct drv_cmd cmd; > @@ -335,7 +334,7 @@ static u32 get_cur_val(const struct cpumask *mask= ) > if (unlikely(cpumask_empty(mask))) > return 0; > =20 > - switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) { > + switch (data->cpu_feature) { > case SYSTEM_INTEL_MSR_CAPABLE: > cmd.type =3D SYSTEM_INTEL_MSR_CAPABLE; > cmd.addr.msr.reg =3D MSR_IA32_PERF_CTL; > @@ -346,7 +345,7 @@ static u32 get_cur_val(const struct cpumask *mask= ) > break; > case SYSTEM_IO_CAPABLE: > cmd.type =3D SYSTEM_IO_CAPABLE; > - perf =3D per_cpu(acfreq_data, cpumask_first(mask))->acpi_data; > + perf =3D data->acpi_data; > cmd.addr.io.port =3D perf->control_register.address; > cmd.addr.io.bit_width =3D perf->control_register.bit_width; > break; > @@ -364,19 +363,24 @@ static u32 get_cur_val(const struct cpumask *ma= sk) > =20 > static unsigned int get_cur_freq_on_cpu(unsigned int cpu) > { > - struct acpi_cpufreq_data *data =3D per_cpu(acfreq_data, cpu); > + struct acpi_cpufreq_data *data; > + struct cpufreq_policy *policy; > unsigned int freq; > unsigned int cached_freq; > =20 > pr_debug("get_cur_freq_on_cpu (%d)\n", cpu); > =20 > - if (unlikely(data =3D=3D NULL || > - data->acpi_data =3D=3D NULL || data->freq_table =3D=3D NULL))= { > + policy =3D cpufreq_cpu_get(cpu); > + if (unlikely(!policy)) > + return 0; > + > + data =3D policy->driver_data; > + cpufreq_cpu_put(policy); > + if (unlikely(!data || !data->acpi_data || !data->freq_table)) > return 0; > - } > =20 > cached_freq =3D data->freq_table[data->acpi_data->state].frequency; > - freq =3D extract_freq(get_cur_val(cpumask_of(cpu)), data); > + freq =3D extract_freq(get_cur_val(cpumask_of(cpu), data), data); > if (freq !=3D cached_freq) { > /* > * The dreaded BIOS frequency change behind our back. > @@ -397,7 +401,7 @@ static unsigned int check_freqs(const struct cpum= ask *mask, unsigned int freq, > unsigned int i; > =20 > for (i =3D 0; i < 100; i++) { > - cur_freq =3D extract_freq(get_cur_val(mask), data); > + cur_freq =3D extract_freq(get_cur_val(mask, data), data); > if (cur_freq =3D=3D freq) > return 1; > udelay(10); > @@ -408,7 +412,7 @@ static unsigned int check_freqs(const struct cpum= ask *mask, unsigned int freq, > static int acpi_cpufreq_target(struct cpufreq_policy *policy, > unsigned int index) > { > - struct acpi_cpufreq_data *data =3D per_cpu(acfreq_data, policy->cpu= ); > + struct acpi_cpufreq_data *data =3D policy->driver_data; > struct acpi_processor_performance *perf; > struct drv_cmd cmd; > unsigned int next_perf_state =3D 0; /* Index into perf table */ > @@ -673,7 +677,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_p= olicy *policy) > } > =20 > data->acpi_data =3D per_cpu_ptr(acpi_perf_data, cpu); > - per_cpu(acfreq_data, cpu) =3D data; > + policy->driver_data =3D data; > =20 > if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) > acpi_cpufreq_driver.flags |=3D CPUFREQ_CONST_LOOPS; > @@ -843,19 +847,19 @@ err_free_mask: > free_cpumask_var(data->freqdomain_cpus); > err_free: > kfree(data); > - per_cpu(acfreq_data, cpu) =3D NULL; > + policy->driver_data =3D NULL; > =20 > return result; > } > =20 > static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy) > { > - struct acpi_cpufreq_data *data =3D per_cpu(acfreq_data, policy->cpu= ); > + struct acpi_cpufreq_data *data =3D policy->driver_data; > =20 > pr_debug("acpi_cpufreq_cpu_exit\n"); > =20 > if (data) { > - per_cpu(acfreq_data, policy->cpu) =3D NULL; > + policy->driver_data =3D NULL; > acpi_processor_unregister_performance(data->acpi_data, > policy->cpu); > free_cpumask_var(data->freqdomain_cpus); > @@ -868,7 +872,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_p= olicy *policy) > =20 > static int acpi_cpufreq_resume(struct cpufreq_policy *policy) > { > - struct acpi_cpufreq_data *data =3D per_cpu(acfreq_data, policy->cpu= ); > + struct acpi_cpufreq_data *data =3D policy->driver_data; > =20 > pr_debug("acpi_cpufreq_resume\n"); > =20 >=20