Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753761AbbHSL57 (ORCPT ); Wed, 19 Aug 2015 07:57:59 -0400 Received: from mail-yk0-f176.google.com ([209.85.160.176]:33896 "EHLO mail-yk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752654AbbHSL55 (ORCPT ); Wed, 19 Aug 2015 07:57:57 -0400 MIME-Version: 1.0 In-Reply-To: References: <20150819062219.GA10032@localhost> Date: Wed, 19 Aug 2015 17:27:56 +0530 Message-ID: Subject: Re: [PATCH] thermal: cpu_cooling: Remove usage of devm functions From: Vaishali Thakkar To: Viresh Kumar Cc: Zhang Rui , Eduardo Valentin , Linux PM list , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3160 Lines: 83 On Wed, Aug 19, 2015 at 1:54 PM, Viresh Kumar wrote: > On Wed, Aug 19, 2015 at 11:52 AM, Vaishali Thakkar > wrote: >> In the function cpufreq_get_requested_power, the memory allocated >> for load_cpu is live within the function only. And after the >> allocation it is immediately freed with devm_kfree. There is no >> need to allocate memory for load_cpu with devm function so replace >> devm_kcalloc with kcalloc and devm_kfree with kfree. >> >> Signed-off-by: Vaishali Thakkar >> --- >> This patch is having one checkpatch.pl warning which suggests that >> kfree(NULL) is safe. But I think leaving code with if is nice >> because it reflects the fact that kcalloc was under an if. So, I >> have ignored checkpatch. If maintainer wants me to go for changing >> things, I am fine with it too. > > I will rather ask you to do this: > > diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c > index 620dcd405ff6..a04055ea5d94 100644 > --- a/drivers/thermal/cpu_cooling.c > +++ b/drivers/thermal/cpu_cooling.c > @@ -584,8 +584,8 @@ static int cpufreq_get_requested_power(struct > thermal_cooling_device *cdev, > if (trace_thermal_power_cpu_get_power_enabled()) { > u32 ncpus = cpumask_weight(&cpufreq_device->allowed_cpus); > > - load_cpu = devm_kcalloc(&cdev->device, ncpus, sizeof(*load_cpu), > - GFP_KERNEL); > + load_cpu = kcalloc(&cdev->device, ncpus, sizeof(*load_cpu), > + GFP_KERNEL); > } Sorry. I forgot to ask you one more thing. devm_kcalloc takes one more argument then kcalloc. So, the change I did is correct I guess. And I'm not sure why you suggested this change? I assume you just want me to correct in my patch for last argument. But that line also comes under 80 characters. > for_each_cpu(cpu, &cpufreq_device->allowed_cpus) { > @@ -607,22 +607,20 @@ static int cpufreq_get_requested_power(struct > thermal_cooling_device *cdev, > > dynamic_power = get_dynamic_power(cpufreq_device, freq); > ret = get_static_power(cpufreq_device, tz, freq, &static_power); > - if (ret) { > - if (load_cpu) > - devm_kfree(&cdev->device, load_cpu); > - return ret; > - } > + if (ret) > + goto free; > > - if (load_cpu) { > + if (load_cpu) > trace_thermal_power_cpu_get_power( > &cpufreq_device->allowed_cpus, > freq, load_cpu, i, dynamic_power, static_power); > > - devm_kfree(&cdev->device, load_cpu); > - } > - > *power = static_power + dynamic_power; > - return 0; > + > +free: > + kfree(&cdev->device, load_cpu); > + > + return ret; > } -- Vaishali -- 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/