user/sven/linux.git/kernel/power, branch v5.14.9

PM: EM: Increase energy calculation precision

2021-09-15T08:02:20Z

[ Upstream commit 7fcc17d0cb12938d2b3507973a6f93fc9ed2c7a1 ] 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 => 100 energy_w_task = 480 * 228 / 1024 = 106.87 => 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 => 127 energy_w_task = 160 * 296 / 355 = 133.41 => 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 Reviewed-by: Dietmar Eggemann Signed-off-by: Lukasz Luba Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM: hibernate: disable when there are active secretmem users

2021-07-08T18:48:21Z

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 Acked-by: David Hildenbrand Acked-by: James Bottomley Cc: Alexander Viro Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christopher Lameter Cc: Dan Williams Cc: Dave Hansen Cc: David Hildenbrand Cc: Elena Reshetova Cc: Hagen Paul Pfeifer Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: James Bottomley Cc: "Kirill A. Shutemov" Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael Kerrisk Cc: Palmer Dabbelt Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Rick Edgecombe Cc: Roman Gushchin Cc: Shakeel Butt Cc: Shuah Khan Cc: Thomas Gleixner Cc: Tycho Andersen Cc: Will Deacon Cc: kernel test robot Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

PM: hibernate: remove leading spaces before tabs

2021-06-11T16:52:05Z

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 Signed-off-by: Rafael J. Wysocki

PM: sleep: remove trailing spaces and tabs

2021-06-11T16:49:09Z

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 Signed-off-by: Rafael J. Wysocki

PM: hibernate: fix spelling mistakes

2021-05-24T14:17:07Z

Fix some spelling mistakes in comments: corresonds ==> corresponds alocated ==> allocated unitialized ==> uninitialized Deompression ==> Decompression Signed-off-by: Zhen Lei Signed-off-by: Rafael J. Wysocki

PM: sleep: fix typos in comments

2021-04-08T17:37:21Z

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 Signed-off-by: Rafael J. Wysocki

PM: EM: postpone creating the debugfs dir till fs_initcall

2021-03-23T18:53:48Z

The debugfs directory '/sys/kernel/debug/energy_model' is needed before the Energy Model registration can happen. With the recent change in debugfs subsystem it's not allowed to create this directory at early stage (core_initcall). Thus creating this directory would fail. Postpone the creation of the EM debug dir to later stage: fs_initcall. It should be safe since all clients: CPUFreq drivers, Devfreq drivers will be initialized in later stages. The custom debug log below prints the time of creation the EM debug dir at fs_initcall and successful registration of EMs at later stages. [ 1.505717] energy_model: creating rootdir [ 3.698307] cpu cpu0: EM: created perf domain [ 3.709022] cpu cpu1: EM: created perf domain Fixes: 56348560d495 ("debugfs: do not attempt to create a new file before the filesystem is initalized") Reported-by: Ionela Voinescu Signed-off-by: Lukasz Luba Reviewed-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki

Merge branches 'powercap' and 'pm-misc'

2021-02-15T17:50:01Z

* powercap: powercap: intel_rapl: Use topology interface in rapl_init_domains() powercap: intel_rapl: Use topology interface in rapl_add_package() powercap/intel_rapl: add support for AlderLake Mobile powercap/drivers/dtpm: Fix size of object being allocated powercap/drivers/dtpm: Fix an IS_ERR() vs NULL check powercap/drivers/dtpm: Fix some missing unlock bugs powercap/drivers/dtpm: Fix a double shift bug powercap/drivers/dtpm: Fix __udivdi3 and __aeabi_uldivmod unresolved symbols powercap/drivers/dtpm: Add CPU energy model based support powercap/drivers/dtpm: Add API for dynamic thermal power management Documentation/powercap/dtpm: Add documentation for dtpm units: Add Watt units * pm-misc: PM: Kconfig: remove unneeded "default n" options PM: EM: update Kconfig description and drop "default n" option

PM: sleep: Constify static struct attribute_group

2021-02-12T15:46:59Z

The only usage of suspend_attr_group is to put its address in an array of pointers to const attribute_group structs. Make it const to allow the compiler to put it into read-only memory. Signed-off-by: Rikard Falkeborn Signed-off-by: Rafael J. Wysocki

PM: Kconfig: remove unneeded "default n" options

2021-02-12T15:43:23Z

Remove "default n" options. If the "default" line is removed, it defaults to 'n'. Signed-off-by: Lukasz Luba Signed-off-by: Rafael J. Wysocki