From: "Rafael J. Wysocki" <rafael@kernel.org>
To: ramesh.thomas@intel.com
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Linux PM <linux-pm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Ulf Hansson <ulf.hansson@linaro.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Tero Kristo <t-kristo@ti.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Alex Shi <alex.shi@linaro.org>
Subject: Re: [RFT][PATCH v2 1/2] PM / domains: Rework governor code to be more consistent
Date: Sat, 4 Nov 2017 12:24:15 +0100 [thread overview]
Message-ID: <CAJZ5v0jXz7FCgmivjwLL-yfK2hHbW2bGAQGjb4YS4cY0JxDQ8w@mail.gmail.com> (raw)
In-Reply-To: <20171104023401.GB29203@intel.com>
On Sat, Nov 4, 2017 at 3:34 AM, Ramesh Thomas <ramesh.thomas@intel.com> wrote:
> On 2017-11-03 at 12:47:20 +0100, Rafael J. Wysocki wrote:
>> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>>
>> The genpd governor currently uses negative PM QoS values to indicate
>> the "no suspend" condition and 0 as "no restriction", but it doesn't
>> use them consistently. Moreover, it tries to refresh QoS values for
>> already suspended devices in a quite questionable way.
>>
>> For the above reasons, rework it to be a bit more consistent.
>>
>> First off, note that dev_pm_qos_read_value() in
>> dev_update_qos_constraint() and __default_power_down_ok() is
>> evaluated for devices in suspend. Moreover, that only happens if the
>> effective_constraint_ns value for them is negative (meaning "no
>> suspend"). It is not evaluated in any other cases, so effectively
>> the QoS values are only updated for devices in suspend that should
>> not have been suspended in the first place. In all of the other
>> cases, the QoS values taken into account are the effective ones from
>> the time before the device has been suspended, so generally devices
>> need to be resumed and suspended again for new QoS values to take
>> effect anyway. Thus evaluating dev_update_qos_constraint() in
>> those two places doesn't make sense at all, so drop it.
>>
>> Second, initialize effective_constraint_ns to 0 ("no constraint")
>> rather than to (-1) ("no suspend"), which makes more sense in
>> general and in case effective_constraint_ns is never updated
>> (the device is in suspend all the time or it is never suspended)
>> it doesn't affect the device's parent and so on.
>>
>> Finally, rework default_suspend_ok() to explicitly handle the
>> "no restriction" special case.
>>
>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> ---
[cut]
> Looks good to me.
>
> Acked-by: Ramesh Thomas <ramesh.thomas@intel.com>
Thanks!
Do you actually mean Reviewed-by?
next prev parent reply other threads:[~2017-11-04 11:24 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 23:00 [RFT][PATCH 0/2] PM / QoS: Device resume latency framework fix Rafael J. Wysocki
2017-11-01 23:01 ` [RFT][PATCH 1/2] PM / domains: Rework governor code to be more consistent Rafael J. Wysocki
2017-11-03 7:05 ` Ramesh Thomas
2017-11-03 7:51 ` Rafael J. Wysocki
2017-11-01 23:03 ` [RFT][PATCH 2/2] PM / QoS: Fix device resume latency framework Rafael J. Wysocki
2017-11-03 7:43 ` Ramesh Thomas
2017-11-03 7:58 ` Rafael J. Wysocki
2017-11-03 10:38 ` Rafael J. Wysocki
2017-11-03 11:42 ` [RFT][PATCH v2 0/2] PM / QoS: Device resume latency framework fix Rafael J. Wysocki
2017-11-03 11:47 ` [RFT][PATCH v2 1/2] PM / domains: Rework governor code to be more consistent Rafael J. Wysocki
2017-11-04 2:34 ` Ramesh Thomas
2017-11-04 11:24 ` Rafael J. Wysocki [this message]
2017-11-06 7:47 ` Ramesh Thomas
2017-11-06 12:10 ` Ulf Hansson
2017-11-06 12:34 ` Rafael J. Wysocki
2017-11-06 12:44 ` Ulf Hansson
2017-11-06 12:49 ` Rafael J. Wysocki
2017-11-06 14:38 ` Ulf Hansson
2017-11-06 23:07 ` Rafael J. Wysocki
2017-11-03 11:50 ` [RFT][PATCH v2 2/2] PM / QoS: Fix device resume latency framework Rafael J. Wysocki
2017-11-03 16:39 ` Reinette Chatre
2017-11-04 2:28 ` Ramesh Thomas
2017-11-04 11:30 ` Rafael J. Wysocki
2017-11-04 11:58 ` Rafael J. Wysocki
2017-11-04 11:28 ` Rafael J. Wysocki
2017-11-04 2:38 ` Ramesh Thomas
2017-11-04 12:34 ` [RFT][Update][PATCH " Rafael J. Wysocki
2017-11-06 17:47 ` Reinette Chatre
2017-11-07 1:07 ` Rafael J. Wysocki
2017-11-06 13:46 ` [RFT][PATCH v2 0/2] PM / QoS: Device resume latency framework fix Geert Uytterhoeven
2017-11-07 1:08 ` Rafael J. Wysocki
2017-11-08 9:09 ` Tero Kristo
2017-11-07 1:17 ` [PATCH v3 " Rafael J. Wysocki
2017-11-07 1:23 ` [PATCH v3 1/2] PM / domains: Rework governor code to be more consistent Rafael J. Wysocki
2017-11-07 5:05 ` Ramesh Thomas
2017-11-07 10:22 ` Rafael J. Wysocki
2017-11-07 23:24 ` Ramesh Thomas
2017-11-10 7:49 ` Ulf Hansson
2017-11-07 1:27 ` [PATCH v3 2/2] PM / QoS: Fix device resume latency framework Rafael J. Wysocki
2017-11-07 4:33 ` Ramesh Thomas
2017-11-07 10:12 ` Rafael J. Wysocki
2017-11-07 10:33 ` [PATCH v4 " Rafael J. Wysocki
2017-11-07 23:15 ` Ramesh Thomas
2017-11-08 0:09 ` Rafael J. Wysocki
2017-11-10 7:49 ` Ulf Hansson
2017-11-10 8:03 ` Geert Uytterhoeven
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