Re: [RFC][PATCH] sched: Optimize cpufreq_update_util

2021-03-19 Thread Viresh Kumar
On 19-03-21, 15:35, Rafael J. Wysocki wrote: > On Friday, March 19, 2021 8:37:51 AM CET Viresh Kumar wrote: > > On 18-03-21, 22:28, Peter Zijlstra wrote: > > > Also, is there a lock order comment in cpufreq somewhere? > > > > I don't think so. > > > > > I tried > > > following it, but eventually

Re: [RFC][PATCH] sched: Optimize cpufreq_update_util

2021-03-19 Thread Rafael J. Wysocki
On Friday, March 19, 2021 8:37:51 AM CET Viresh Kumar wrote: > On 18-03-21, 22:28, Peter Zijlstra wrote: > > Also, is there a lock order comment in cpufreq somewhere? > > I don't think so. > > > I tried > > following it, but eventually gave up and figured 'asking' lockdep was > > far simpler. >

Re: [RFC][PATCH] sched: Optimize cpufreq_update_util

2021-03-19 Thread Viresh Kumar
On 18-03-21, 22:28, Peter Zijlstra wrote: > Also, is there a lock order comment in cpufreq somewhere? I don't think so. > I tried > following it, but eventually gave up and figured 'asking' lockdep was > far simpler. This will get called from CPU's online/offline path at worst, nothing more. >

[RFC][PATCH] sched: Optimize cpufreq_update_util

2021-03-18 Thread Peter Zijlstra
Hi, The below replaces cpufreq_update_util()'s indirect call with a static_call(). The patch is quite gross, and we definitely need static_call_update_cpuslocked(). cpufreq folks, is there a better way to do that optimize pass? That is, we need to know when all CPUs have the *same* function set