From: "Doug Smythies" <dsmythies@telus.net>
To: "'Rafael J. Wysocki'" <rjw@rjwysocki.net>
Cc: "'Rafael J. Wysocki'" <rafael@kernel.org>,
"'Linux Documentation'" <linux-doc@vger.kernel.org>,
"'LKML'" <linux-kernel@vger.kernel.org>,
"'Peter Zijlstra'" <peterz@infradead.org>,
"'Srinivas Pandruvada'" <srinivas.pandruvada@linux.intel.com>,
"'Giovanni Gherdovich'" <ggherdovich@suse.cz>,
"'Francisco Jerez'" <francisco.jerez.plata@intel.com>,
"'Linux PM'" <linux-pm@vger.kernel.org>
Subject: RE: [PATCH] cpufreq: intel_pstate: Implement passive mode with HWP enabled
Date: Wed, 5 Aug 2020 22:54:47 -0700 [thread overview]
Message-ID: <004601d66bb6$199ce1a0$4cd6a4e0$@net> (raw)
In-Reply-To: <2418846.A4mPlhI7ni@kreacher>
On 2020.08.03 10:09 Rafael J. Wysocki wrote:
> On Sunday, August 2, 2020 5:17:39 PM CEST Doug Smythies wrote:
> > On 2020.07.19 04:43 Rafael J. Wysocki wrote:
> > > On Fri, Jul 17, 2020 at 3:37 PM Doug Smythies <dsmythies@telus.net> wrote:
> > > > On 2020.07.16 05:08 Rafael J. Wysocki wrote:
> > > > > On Wed, Jul 15, 2020 at 10:39 PM Doug Smythies <dsmythies@telus.net> wrote:
> > > > >> On 2020.07.14 11:16 Rafael J. Wysocki wrote:
> > > > >> >
> > > > >> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > > >> ...
> > > > >> > Since the passive mode hasn't worked with HWP at all, and it is not going to
> > > > >> > the default for HWP systems anyway, I don't see any drawbacks related to making
> > > > >> > this change, so I would consider this as 5.9 material unless there are any
> > > > >> > serious objections.
> > > > >>
> > > > >> Good point.
> > > >
> > > > Actually, for those users that default to passive mode upon boot,
> > > > this would mean they would find themselves using this.
> > > > Also, it isn't obvious, from the typical "what driver and what governor"
> > > > inquiry.
> > >
> > > So the change in behavior is that after this patch
> > > intel_pstate=passive doesn't imply no_hwp any more.
> > >
> > > That's a very minor difference though and I'm not aware of any adverse
> > > effects it can cause on HWP systems anyway.
> >
> > My point was, that it will now default to something where
> > testing has not been completed.
> >
> > > The "what governor" is straightforward in the passive mode: that's
> > > whatever cpufreq governor has been selected.
> >
> > I think you might have missed my point.
> > From the normal methods of inquiry one does not know
> > if HWP is being used or not. Why? Because with
> > or without HWP one gets the same answers under:
> >
> > /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver
> > /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
>
> Yes, but this is also the case in the active mode, isn't it?
Yes, fair enough.
But we aren't changing what it means by default
between kernel 5.8 and 5.9-rc1.
... Doug
next prev parent reply other threads:[~2020-08-06 11:04 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 18:16 [PATCH] cpufreq: intel_pstate: Implement passive mode with HWP enabled Rafael J. Wysocki
2020-07-15 0:09 ` Francisco Jerez
2020-07-15 12:04 ` Rafael J. Wysocki
2020-07-15 21:35 ` Francisco Jerez
2020-07-16 1:14 ` Srinivas Pandruvada
2020-07-16 14:33 ` Rafael J. Wysocki
2020-07-16 14:32 ` Rafael J. Wysocki
2020-07-17 0:21 ` Francisco Jerez
2020-07-19 19:06 ` Rafael J. Wysocki
2020-07-20 23:20 ` Francisco Jerez
2020-07-21 16:25 ` Srinivas Pandruvada
2020-07-21 23:14 ` Francisco Jerez
2020-07-27 17:23 ` Rafael J. Wysocki
2020-07-27 17:15 ` Rafael J. Wysocki
2020-07-28 2:32 ` Francisco Jerez
2020-07-28 18:27 ` Rafael J. Wysocki
2020-07-29 5:46 ` Francisco Jerez
2020-07-29 17:52 ` Rafael J. Wysocki
2020-07-30 0:49 ` Francisco Jerez
2020-07-31 17:52 ` Rafael J. Wysocki
2020-07-31 22:43 ` Francisco Jerez
2020-07-28 15:41 ` Rafael J. Wysocki
2020-07-15 20:39 ` Doug Smythies
2020-07-16 12:07 ` Rafael J. Wysocki
2020-07-17 13:37 ` Doug Smythies
2020-07-19 11:42 ` Rafael J. Wysocki
2020-08-02 15:17 ` Doug Smythies
2020-08-03 17:08 ` Rafael J. Wysocki
2020-08-06 5:54 ` Doug Smythies [this message]
2020-08-06 11:39 ` Rafael J. Wysocki
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