From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sumit Gupta Subject: Re: [TEGRA194_CPUFREQ Patch 2/3] cpufreq: Add Tegra194 cpufreq driver Date: Thu, 16 Apr 2020 12:36:30 +0530 Message-ID: <8ea80551-b47c-3dd5-4efa-6befecc279e1@nvidia.com> References: <20200406025549.qfwzlk3745y3r274@vireshk-i7> <3ab4136c-8cca-c2f9-d286-b82dac23e720@nvidia.com> <20200408055301.jhvu5bc2luu3b5qr@vireshk-i7> <08307e54-0e14-14a3-7d6a-d59e1e04a683@nvidia.com> <20200409074415.twpzu2n4frqlde7b@vireshk-i7> <00390070-38a1-19aa-ca59-42c4658bee7e@nvidia.com> <20200413062141.a6hmwipexhv3sctq@vireshk-i7> <64b609f1-efb1-425f-a91a-27a492bd3ec4@nvidia.com> <20200414054504.e3qn2cnxqur4sclw@vireshk-i7> <20200416033715.hscztwkxie2o5i3r@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200416033715.hscztwkxie2o5i3r@vireshk-i7> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Viresh Kumar Cc: rjw@rjwysocki.net, catalin.marinas@arm.com, will@kernel.org, thierry.reding@gmail.com, jonathanh@nvidia.com, talho@nvidia.com, linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, bbasu@nvidia.com, mperttunen@nvidia.com, Sumit Gupta List-Id: linux-tegra@vger.kernel.org On 16/04/20 9:07 AM, Viresh Kumar wrote: > External email: Use caution opening links or attachments > > > On 15-04-20, 16:55, Sumit Gupta wrote: >> >> >> On 14/04/20 11:15 AM, Viresh Kumar wrote: >>> External email: Use caution opening links or attachments >>> >>> >>> On 13-04-20, 17:50, Sumit Gupta wrote: >>>> This was done considering long delay value as explained previously. >>>> Do you think that smp_call_function_single() would be better than work queue >>>> here? >>> >>> Don't work with assumptions, you should test both and see which one >>> works better. Workqueue should never be faster than >>> smp_call_function_single() with my understanding. >> Checked the time taken and its almost same in both cases. >> Earlier we used smp_call_function_single(), but delay time period was small >> in that SOC. In T194, the time period was more. So, this is an optimization >> done because using work queue has advantage as interrupts will not be >> disabled for that period. > > Hmm, okay, keep the workqueue and mention the required details in a > comment for everyone to understand why the implementation is done that > way. > sure, thank you! > -- > viresh >