lkml.org 
[lkml]   [2017]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH] cpufreq: intel_pstate: Fix cpuinfo_cur_freq after performance governor changes
Date
Hi Rafael,

If you delete "get" function implement within intel_pstate, the
sysfs interface cpuinfo_cur_freq will display <unknown> all the time.
To be honest, at the beginning I have consider this way like you
patched, but based two reasons below, it is conservative for us to do that.

1. I am worried about whether it would lead to confusion for customers or
Linux OS venders who are accustomed to cpuinfo_cur_freq.
2. This is the first time for me to offer patch to intel_pstate, not sure
whether it could be accepted by you.

> On Monday, July 24, 2017 03:32:47 PM Huaisheng HS1 Ye wrote:
> > Hi Rafael,
> > Thanks for your reply.
> >
> > > On Monday, July 24, 2017 05:43:14 AM Huaisheng HS1 Ye wrote:
> > > > After commit 82b4e03e01bc (intel_pstate: skip scheduler hook when
> > > > in "performance" mode) Software P-state control modes couldn't get
> > > > dynamic value during performance mode,
> > >
> > > Please explain what you mean here.
> > >
> > commit 82b4e03e01bc (intel_pstate: skip scheduler hook when in
> > "performance" mode) disables intel_pstate_set_update_util_hook when
> > current policy is performance within function intel_pstate_set_policy.
> > It leads to Software P-states couldn't update sysfs interface
> > cpuinfo_cur_freq's value during performance mode, because of
> > pstate_funcs.update_util couldn't set for the given CPU.
> >
> > > I guess you carried out some tests and the results were not as
> > > expected, so what was the test?
> > Exactly, we check the sysfs interface cpuinfo_cur_freq and the output
> > of cpupower frequency-info both with performance mode.
>
> OK, so what about the change below:
>
> ---
> drivers/cpufreq/intel_pstate.c | 8 --------
> 1 file changed, 8 deletions(-)
>
> Index: linux-pm/drivers/cpufreq/intel_pstate.c
> ==============================================================
> =====
> --- linux-pm.orig/drivers/cpufreq/intel_pstate.c
> +++ linux-pm/drivers/cpufreq/intel_pstate.c
> @@ -1674,13 +1674,6 @@ static int intel_pstate_init_cpu(unsigne
> return 0;
> }
>
> -static unsigned int intel_pstate_get(unsigned int cpu_num) -{
> - struct cpudata *cpu = all_cpu_data[cpu_num];
> -
> - return cpu ? get_avg_frequency(cpu) : 0;
> -}
> -
> static void intel_pstate_set_update_util_hook(unsigned int cpu_num) {
> struct cpudata *cpu = all_cpu_data[cpu_num]; @@ -1921,7 +1914,6 @@
> static struct cpufreq_driver intel_pstat
> .setpolicy = intel_pstate_set_policy,
> .suspend = intel_pstate_hwp_save_state,
> .resume = intel_pstate_resume,
> - .get = intel_pstate_get,
> .init = intel_pstate_cpu_init,
> .exit = intel_pstate_cpu_exit,
> .stop_cpu = intel_pstate_stop_cpu,

\
 
 \ /
  Last update: 2017-07-25 03:47    [W:1.698 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site