<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux/kernel/power, branch v5.15</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
</subtitle>
<id>https://git.shady.money/linux/atom?h=v5.15</id>
<link rel='self' href='https://git.shady.money/linux/atom?h=v5.15'/>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/'/>
<updated>2021-08-30T17:25:42Z</updated>
<entry>
<title>Merge branches 'pm-pci', 'pm-sleep', 'pm-domains' and 'powercap'</title>
<updated>2021-08-30T17:25:42Z</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2021-08-30T17:25:42Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=fe583359ddf0d509275b87b635fa8b2e3794321e'/>
<id>urn:sha1:fe583359ddf0d509275b87b635fa8b2e3794321e</id>
<content type='text'>
* pm-pci:
  PCI: PM: Enable PME if it can be signaled from D3cold
  PCI: PM: Avoid forcing PCI_D0 for wakeup reasons inconsistently
  PCI: Use pci_update_current_state() in pci_enable_device_flags()

* pm-sleep:
  PM: sleep: unmark 'state' functions as kernel-doc
  PM: sleep: check RTC features instead of ops in suspend_test
  PM: sleep: s2idle: Replace deprecated CPU-hotplug functions

* pm-domains:
  PM: domains: Fix domain attach for CONFIG_PM_OPP=n
  arm64: dts: sc7180: Add required-opps for i2c
  PM: domains: Add support for 'required-opps' to set default perf state
  opp: Don't print an error if required-opps is missing

* powercap:
  powercap: Add Power Limit4 support for Alder Lake SoC
  powercap: intel_rapl: Replace deprecated CPU-hotplug functions
</content>
</entry>
<entry>
<title>PM: sleep: unmark 'state' functions as kernel-doc</title>
<updated>2021-08-16T16:49:39Z</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2021-08-10T01:44:42Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=dbcfa7156f48ebb72dfc8f4e5d702af8ca1d4b3a'/>
<id>urn:sha1:dbcfa7156f48ebb72dfc8f4e5d702af8ca1d4b3a</id>
<content type='text'>
Fix kernel-doc warnings in kernel/power/main.c by unmarking the
comment block as kernel-doc notation. This eliminates the following
kernel-doc warnings:

kernel/power/main.c:593: warning: expecting prototype for state(). Prototype was for state_show() instead
kernel/power/main.c:593: warning: Function parameter or member 'kobj' not described in 'state_show'
kernel/power/main.c:593: warning: Function parameter or member 'attr' not described in 'state_show'
kernel/power/main.c:593: warning: Function parameter or member 'buf' not described in 'state_show'

Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: EM: Increase energy calculation precision</title>
<updated>2021-08-06T13:30:42Z</updated>
<author>
<name>Lukasz Luba</name>
<email>lukasz.luba@arm.com</email>
</author>
<published>2021-08-03T10:27:43Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=7fcc17d0cb12938d2b3507973a6f93fc9ed2c7a1'/>
<id>urn:sha1:7fcc17d0cb12938d2b3507973a6f93fc9ed2c7a1</id>
<content type='text'>
The Energy Model (EM) provides useful information about device power in
each performance state to other subsystems like: Energy Aware Scheduler
(EAS). The energy calculation in EAS does arithmetic operation based on
the EM em_cpu_energy(). Current implementation of that function uses
em_perf_state::cost as a pre-computed cost coefficient equal to:
cost = power * max_frequency / frequency.
The 'power' is expressed in milli-Watts (or in abstract scale).

There are corner cases when the EAS energy calculation for two Performance
Domains (PDs) return the same value. The EAS compares these values to
choose smaller one. It might happen that this values are equal due to
rounding error. In such scenario, we need better resolution, e.g. 1000
times better. To provide this possibility increase the resolution in the
em_perf_state::cost for 64-bit architectures. The cost of increasing
resolution on 32-bit is pretty high (64-bit division) and is not justified
since there are no new 32bit big.LITTLE EAS systems expected which would
benefit from this higher resolution.

This patch allows to avoid the rounding to milli-Watt errors, which might
occur in EAS energy estimation for each PD. The rounding error is common
for small tasks which have small utilization value.

There are two places in the code where it makes a difference:
1. In the find_energy_efficient_cpu() where we are searching for
best_delta. We might suffer there when two PDs return the same result,
like in the example below.

Scenario:
Low utilized system e.g. ~200 sum_util for PD0 and ~220 for PD1. There
are quite a few small tasks ~10-15 util. These tasks would suffer for
the rounding error. These utilization values are typical when running games
on Android. One of our partners has reported 5..10mA less battery drain
when running with increased resolution.

Some details:
We have two PDs: PD0 (big) and PD1 (little)
Let's compare w/o patch set ('old') and w/ patch set ('new')
We are comparing energy w/ task and w/o task placed in the PDs

a) 'old' w/o patch set, PD0
task_util = 13
cost = 480
sum_util_w/o_task = 215
sum_util_w_task = 228
scale_cpu = 1024
energy_w/o_task = 480 * 215 / 1024 = 100.78 =&gt; 100
energy_w_task = 480 * 228 / 1024 = 106.87 =&gt; 106
energy_diff = 106 - 100 = 6
(this is equal to 'old' PD1's energy_diff in 'c)')

b) 'new' w/ patch set, PD0
task_util = 13
cost = 480 * 1000 = 480000
sum_util_w/o_task = 215
sum_util_w_task = 228
energy_w/o_task = 480000 * 215 / 1024 = 100781
energy_w_task = 480000 * 228 / 1024  = 106875
energy_diff = 106875 - 100781 = 6094
(this is not equal to 'new' PD1's energy_diff in 'd)')

c) 'old' w/o patch set, PD1
task_util = 13
cost = 160
sum_util_w/o_task = 283
sum_util_w_task = 293
scale_cpu = 355
energy_w/o_task = 160 * 283 / 355 = 127.55 =&gt; 127
energy_w_task = 160 * 296 / 355 = 133.41 =&gt; 133
energy_diff = 133 - 127 = 6
(this is equal to 'old' PD0's energy_diff in 'a)')

d) 'new' w/ patch set, PD1
task_util = 13
cost = 160 * 1000 = 160000
sum_util_w/o_task = 283
sum_util_w_task = 293
scale_cpu = 355
energy_w/o_task = 160000 * 283 / 355 = 127549
energy_w_task = 160000 * 296 / 355 =   133408
energy_diff = 133408 - 127549 = 5859
(this is not equal to 'new' PD0's energy_diff in 'b)')

2. Difference in the 6% energy margin filter at the end of
find_energy_efficient_cpu(). With this patch the margin comparison also
has better resolution, so it's possible to have better task placement
thanks to that.

Fixes: 27871f7a8a341ef ("PM: Introduce an Energy Model management framework")
Reported-by: CCJ Yeh &lt;CCj.Yeh@mediatek.com&gt;
Reviewed-by: Dietmar Eggemann &lt;dietmar.eggemann@arm.com&gt;
Signed-off-by: Lukasz Luba &lt;lukasz.luba@arm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: sleep: check RTC features instead of ops in suspend_test</title>
<updated>2021-08-04T18:23:05Z</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2021-08-04T10:44:07Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=4fac49fd0a349aa3afb3ad7ec778a00592c7ab59'/>
<id>urn:sha1:4fac49fd0a349aa3afb3ad7ec778a00592c7ab59</id>
<content type='text'>
Test RTC_FEATURE_ALARM instead of relying on ops-&gt;set_alarm to know whether
alarms are available.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: sleep: s2idle: Replace deprecated CPU-hotplug functions</title>
<updated>2021-08-04T18:18:13Z</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2021-08-03T14:16:13Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=d2c8cce647f3022d5960a3bf2b50a2da341d9c8b'/>
<id>urn:sha1:d2c8cce647f3022d5960a3bf2b50a2da341d9c8b</id>
<content type='text'>
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: hibernate: disable when there are active secretmem users</title>
<updated>2021-07-08T18:48:21Z</updated>
<author>
<name>Mike Rapoport</name>
<email>rppt@linux.ibm.com</email>
</author>
<published>2021-07-08T01:08:07Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=9a436f8ff6316c3c1a21a758e14ded930bd615d9'/>
<id>urn:sha1:9a436f8ff6316c3c1a21a758e14ded930bd615d9</id>
<content type='text'>
It is unsafe to allow saving of secretmem areas to the hibernation
snapshot as they would be visible after the resume and this essentially
will defeat the purpose of secret memory mappings.

Prevent hibernation whenever there are active secret memory users.

Link: https://lkml.kernel.org/r/20210518072034.31572-6-rppt@kernel.org
Signed-off-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christopher Lameter &lt;cl@linux.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Elena Reshetova &lt;elena.reshetova@intel.com&gt;
Cc: Hagen Paul Pfeifer &lt;hagen@jauu.net&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Bottomley &lt;jejb@linux.ibm.com&gt;
Cc: "Kirill A. Shutemov" &lt;kirill@shutemov.name&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Michael Kerrisk &lt;mtk.manpages@gmail.com&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Palmer Dabbelt &lt;palmerdabbelt@google.com&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Cc: Roman Gushchin &lt;guro@fb.com&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tycho Andersen &lt;tycho@tycho.ws&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>PM: hibernate: remove leading spaces before tabs</title>
<updated>2021-06-11T16:52:05Z</updated>
<author>
<name>Zhen Lei</name>
<email>thunder.leizhen@huawei.com</email>
</author>
<published>2021-06-08T08:13:14Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=480f0de68caddfe336b8cc0c74a40328779940d3'/>
<id>urn:sha1:480f0de68caddfe336b8cc0c74a40328779940d3</id>
<content type='text'>
 1) Run the following command to find and remove the leading spaces
    before tabs:
    $ find kernel/power/ -type f | xargs sed -r -i 's/^[ ]+\t/\t/'
 2) Manually check and correct if necessary

Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: sleep: remove trailing spaces and tabs</title>
<updated>2021-06-11T16:49:09Z</updated>
<author>
<name>Zhen Lei</name>
<email>thunder.leizhen@huawei.com</email>
</author>
<published>2021-06-08T07:44:37Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=03466883a0fdb5c38f2907b027565b9f253688a8'/>
<id>urn:sha1:03466883a0fdb5c38f2907b027565b9f253688a8</id>
<content type='text'>
Run the following command to find and remove the trailing spaces and tabs:

$ find kernel/power/ -type f | xargs sed -r -i 's/[ \t]+$//'

Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: hibernate: fix spelling mistakes</title>
<updated>2021-05-24T14:17:07Z</updated>
<author>
<name>Zhen Lei</name>
<email>thunder.leizhen@huawei.com</email>
</author>
<published>2021-05-24T09:30:10Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=6be2408a1ef632a48149044d1757c80ab1096213'/>
<id>urn:sha1:6be2408a1ef632a48149044d1757c80ab1096213</id>
<content type='text'>
Fix some spelling mistakes in comments:

corresonds ==&gt; corresponds
alocated ==&gt; allocated
unitialized ==&gt; uninitialized
Deompression ==&gt; Decompression

Signed-off-by: Zhen Lei &lt;thunder.leizhen@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
<entry>
<title>PM: sleep: fix typos in comments</title>
<updated>2021-04-08T17:37:21Z</updated>
<author>
<name>Lu Jialin</name>
<email>lujialin4@huawei.com</email>
</author>
<published>2021-04-08T08:14:44Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=e4b2897ae1a81cce79a8f5fcceda74c3f31c4b73'/>
<id>urn:sha1:e4b2897ae1a81cce79a8f5fcceda74c3f31c4b73</id>
<content type='text'>
Change "occured" to "occurred" in kernel/power/autosleep.c.

Change "consiting" to "consisting" in kernel/power/snapshot.c.

Change "avaiable" to "available" in kernel/power/swap.c.

No functionality changed.

Signed-off-by: Lu Jialin &lt;lujialin4@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
</entry>
</feed>
