user/sven/linux.git/kernel/power, branch v5.10.77

PM: EM: Increase energy calculation precision

2021-09-15T07:50:37Z

[ 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: EM: postpone creating the debugfs dir till fs_initcall

2021-03-30T12:32:04Z

[ Upstream commit fb9d62b27ab1e07d625591549c314b7d406d21df ] 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 Signed-off-by: Sasha Levin

PM: hibernate: flush swap writer after marking

2021-02-03T22:28:40Z

commit fef9c8d28e28a808274a18fbd8cc2685817fd62a upstream. Flush the swap writer after, not before, marking the files, to ensure the signature is properly written. Fixes: 6f612af57821 ("PM / Hibernate: Group swap ops") Signed-off-by: Laurent Badel Cc: All applicable Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: sleep: fix typo in kernel/power/process.c

2020-10-27T18:11:44Z

Fix a typo in a comment in freeze_processes(). Signed-off-by: Jackie Zamow [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

kernel/: fix repeated words in comments

2020-10-16T18:11:19Z

Fix multiple occurrences of duplicated words in kernel/. Fix one typo/spello on the same line as a duplicate word. Change one instance of "the the" to "that the". Otherwise just drop one of the repeated words. Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.org Signed-off-by: Linus Torvalds

Merge tag 'pm-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2020-10-14T17:45:41Z

Pull power management updates from Rafael Wysocki: "These rework the collection of cpufreq statistics to allow it to take place if fast frequency switching is enabled in the governor, rework the frequency invariance handling in the cpufreq core and drivers, add new hardware support to a couple of cpufreq drivers, fix a number of assorted issues and clean up the code all over. Specifics: - Rework cpufreq statistics collection to allow it to take place when fast frequency switching is enabled in the governor (Viresh Kumar). - Make the cpufreq core set the frequency scale on behalf of the driver and update several cpufreq drivers accordingly (Ionela Voinescu, Valentin Schneider). - Add new hardware support to the STI and qcom cpufreq drivers and improve them (Alain Volmat, Manivannan Sadhasivam). - Fix multiple assorted issues in cpufreq drivers (Jon Hunter, Krzysztof Kozlowski, Matthias Kaehlcke, Pali Rohár, Stephan Gerhold, Viresh Kumar). - Fix several assorted issues in the operating performance points (OPP) framework (Stephan Gerhold, Viresh Kumar). - Allow devfreq drivers to fetch devfreq instances by DT enumeration instead of using explicit phandles and modify the devfreq core code to support driver-specific devfreq DT bindings (Leonard Crestez, Chanwoo Choi). - Improve initial hardware resetting in the tegra30 devfreq driver and clean up the tegra cpuidle driver (Dmitry Osipenko). - Update the cpuidle core to collect state entry rejection statistics and expose them via sysfs (Lina Iyer). - Improve the ACPI _CST code handling diagnostics (Chen Yu). - Update the PSCI cpuidle driver to allow the PM domain initialization to occur in the OSI mode as well as in the PC mode (Ulf Hansson). - Rework the generic power domains (genpd) core code to allow domain power off transition to be aborted in the absence of the "power off" domain callback (Ulf Hansson). - Fix two suspend-to-idle issues in the ACPI EC driver (Rafael Wysocki). - Fix the handling of timer_expires in the PM-runtime framework on 32-bit systems and the handling of device links in it (Grygorii Strashko, Xiang Chen). - Add IO requests batching support to the hibernate image saving and reading code and drop a bogus get_gendisk() from there (Xiaoyi Chen, Christoph Hellwig). - Allow PCIe ports to be put into the D3cold power state if they are power-manageable via ACPI (Lukas Wunner). - Add missing header file include to a power capping driver (Pujin Shi). - Clean up the qcom-cpr AVS driver a bit (Liu Shixin). - Kevin Hilman steps down as designated reviwer of adaptive voltage scaling (AVS) drivers (Kevin Hilman)" * tag 'pm-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (65 commits) cpufreq: stats: Fix string format specifier mismatch arm: disable frequency invariance for CONFIG_BL_SWITCHER cpufreq,arm,arm64: restructure definitions of arch_set_freq_scale() cpufreq: stats: Add memory barrier to store_reset() cpufreq: schedutil: Simplify sugov_fast_switch() ACPI: EC: PM: Drop ec_no_wakeup check from acpi_ec_dispatch_gpe() ACPI: EC: PM: Flush EC work unconditionally after wakeup PCI/ACPI: Whitelist hotplug ports for D3 if power managed by ACPI PM: hibernate: remove the bogus call to get_gendisk() in software_resume() cpufreq: Move traces and update to policy->cur to cpufreq core cpufreq: stats: Enable stats for fast-switch as well cpufreq: stats: Mark few conditionals with unlikely() cpufreq: stats: Remove locking cpufreq: stats: Defer stats update to cpufreq_stats_record_transition() PM: domains: Allow to abort power off when no ->power_off() callback PM: domains: Rename power state enums for genpd PM / devfreq: tegra30: Improve initial hardware resetting PM / devfreq: event: Change prototype of devfreq_event_get_edev_by_phandle function PM / devfreq: Change prototype of devfreq_get_devfreq_by_phandle function PM / devfreq: Add devfreq_get_devfreq_by_node function ...

Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

2020-10-13T19:12:44Z

Pull block updates from Jens Axboe: - Series of merge handling cleanups (Baolin, Christoph) - Series of blk-throttle fixes and cleanups (Baolin) - Series cleaning up BDI, seperating the block device from the backing_dev_info (Christoph) - Removal of bdget() as a generic API (Christoph) - Removal of blkdev_get() as a generic API (Christoph) - Cleanup of is-partition checks (Christoph) - Series reworking disk revalidation (Christoph) - Series cleaning up bio flags (Christoph) - bio crypt fixes (Eric) - IO stats inflight tweak (Gabriel) - blk-mq tags fixes (Hannes) - Buffer invalidation fixes (Jan) - Allow soft limits for zone append (Johannes) - Shared tag set improvements (John, Kashyap) - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel) - DM no-wait support (Mike, Konstantin) - Request allocation improvements (Ming) - Allow md/dm/bcache to use IO stat helpers (Song) - Series improving blk-iocost (Tejun) - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang, Xianting, Yang, Yufen, yangerkun) * tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits) block: fix uapi blkzoned.h comments blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue blk-mq: get rid of the dead flush handle code path block: get rid of unnecessary local variable block: fix comment and add lockdep assert blk-mq: use helper function to test hw stopped block: use helper function to test queue register block: remove redundant mq check block: invoke blk_mq_exit_sched no matter whether have .exit_sched percpu_ref: don't refer to ref->data if it isn't allocated block: ratelimit handle_bad_sector() message blk-throttle: Re-use the throtl_set_slice_end() blk-throttle: Open code __throtl_de/enqueue_tg() blk-throttle: Move service tree validation out of the throtl_rb_first() blk-throttle: Move the list operation after list validation blk-throttle: Fix IO hang for a corner case blk-throttle: Avoid tracking latency if low limit is invalid blk-throttle: Avoid getting the current time if tg->last_finish_time is 0 blk-throttle: Remove a meaningless parameter for throtl_downgrade_state() block: Remove redundant 'return' statement ...

PM: hibernate: remove the bogus call to get_gendisk() in software_resume()

2020-10-05T16:42:58Z

get_gendisk grabs a reference on the disk and file operation, so this code will leak both of them while having absolutely no use for the gendisk itself. This effectively reverts commit 2df83fa4bce421f ("PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format") Signed-off-by: Christoph Hellwig Signed-off-by: Rafael J. Wysocki

PM: hibernate: Batch hibernate and resume IO requests

2020-09-28T13:58:18Z

Hibernate and resume process submits individual IO requests for each page of the data, so use blk_plug to improve the batching of these requests. Testing this change with hibernate and resumes consistently shows merging of the IO requests and more than an order of magnitude improvement in hibernate and resume speed is observed. One hibernate and resume cycle for 16GB RAM out of 32GB in use takes around 21 minutes before the change, and 1 minutes after the change on a system with limited storage IOPS. Signed-off-by: Xiaoyi Chen Co-Developed-by: Anchal Agarwal Signed-off-by: Anchal Agarwal [ rjw: Subject and changelog edits, white space damage fixes ] Signed-off-by: Rafael J. Wysocki

PM: mm: cleanup swsusp_swap_check

2020-09-23T16:43:19Z

Use blkdev_get_by_dev instead of bdget + blkdev_get. Signed-off-by: Christoph Hellwig Acked-by: Rafael J. Wysocki Signed-off-by: Jens Axboe