linux-kernel - RE: [PATCH v2 0/5] cpufreq: intel_pstate: Address some HWP-related oddities

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Message-ID: <004a01d67b23$c9829b60$5c87d220$@net>
Date:   Tue, 25 Aug 2020 14:07:46 -0700
From:   "Doug Smythies" <dsmythies@...us.net>
To:     "'Srinivas Pandruvada'" <srinivas.pandruvada@...ux.intel.com>
Cc:     "'LKML'" <linux-kernel@...r.kernel.org>,
        "'Linux PM'" <linux-pm@...r.kernel.org>,
        "'Rafael J. Wysocki'" <rjw@...ysocki.net>
Subject: RE: [PATCH v2 0/5] cpufreq: intel_pstate: Address some HWP-related oddities

Hi Srinivas,

Thanks for your reply.

On 2020.08.25 08:12 Srinivas Pandruvada wrote:
> On Mon, 2020-08-24 at 18:00 -0700, Doug Smythies wrote:
> > I think there is a disconnect between your written
> > description of what is going on and your supporting MSR reads.
> >
> I reproduced again.
> I see the copy paste individual at the first place swapped.

Yes, and that had me confused, initially.

> I pasted the full output by direct copy - paste from the screen.
> 
> But the issues are still there.

Agreed.
I didn't try your offline/online of CPU 1 part previously,
but did now, and get the same results as you.

I did not know that "rdmsr -a 0x774" lists
stuff in the order that CPU were last brought on-line.
I had assumed the list was in CPU order. Weird.

My example (nothing new here, just me catching up.
The offline/online order was cpu1, then cpu3, then cpu2):

root@s18:/sys/devices/system/cpu# grep . cpu*/cpufreq/energy_performance_preference
cpu0/cpufreq/energy_performance_preference:balance_performance
cpu1/cpufreq/energy_performance_preference:127
cpu2/cpufreq/energy_performance_preference:125
cpu3/cpufreq/energy_performance_preference:126
cpu4/cpufreq/energy_performance_preference:balance_performance
cpu5/cpufreq/energy_performance_preference:balance_performance
root@s18:/sys/devices/system/cpu# rdmsr -p 0 0x774
80002e2e
root@s18:/sys/devices/system/cpu# rdmsr -p 1 0x774
7f002e2e
root@s18:/sys/devices/system/cpu# rdmsr -p 2 0x774
7d002e2e
root@s18:/sys/devices/system/cpu# rdmsr -p 3 0x774
7e002e2e
root@s18:/sys/devices/system/cpu# rdmsr -p 4 0x774
80002e2e
root@s18:/sys/devices/system/cpu# rdmsr -p 5 0x774
80002e2e
root@s18:/sys/devices/system/cpu# rdmsr -a 0x774
80002e2e
80002e2e
80002e2e
7f002e2e
7e002e2e
7d002e2e

... Doug