BMC/Intel-BMC/linux.git/kernel/sched/idle.c, branch dev-5.8-intel

cpuidle: Rearrange s2idle-specific idle state entry code

2020-06-25T11:52:53+00:00

Implement call_cpuidle_s2idle() in analogy with call_cpuidle() for the s2idle-specific idle state entry and invoke it from cpuidle_idle_call() to make the s2idle-specific idle entry code path look more similar to the "regular" idle entry one. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Chen Yu

sched: Replace rq::wake_list

2020-05-28T08:54:16+00:00

The recent commit: 90b5363acd47 ("sched: Clean up scheduler_ipi()") got smp_call_function_single_async() subtly wrong. Even though it will return -EBUSY when trying to re-use a csd, that condition is not atomic and still requires external serialization. The change in ttwu_queue_remote() got this wrong. While on first reading ttwu_queue_remote() has an atomic test-and-set that appears to serialize the use, the matching 'release' is not in the right place to actually guarantee this serialization. The actual race is vs the sched_ttwu_pending() call in the idle loop; that can run the wakeup-list without consuming the CSD. Instead of trying to chain the lists, merge them. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200526161908.129371594@infradead.org

smp: Optimize send_call_function_single_ipi()

2020-05-28T08:54:15+00:00

Just like the ttwu_queue_remote() IPI, make use of _TIF_POLLING_NRFLAG to avoid sending IPIs to idle CPUs. [ mingo: Fix UP build bug. ] Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200526161907.953304789@infradead.org

idle: fix spelling mistake "iterrupts" -> "interrupts"

2020-01-17T09:19:22+00:00

There is a spelling misake in comments of cpuidle_idle_call. Fix it. Signed-off-by: Hewenliang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt (VMware) Link: https://lkml.kernel.org/r/20200110025604.34373-1-hewenliang4@huawei.com

Merge tag 'pm-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2019-11-27T03:06:44+00:00

Pull power management updates from Rafael Wysocki: "These include cpuidle changes to use nanoseconds (instead of microseconds) as the unit of time and to simplify checks for disabled idle states in the idle loop, some cpuidle fixes and governor updates, assorted cpufreq updates (driver updates mostly and a few core fixes and cleanups), devfreq updates (dominated by the tegra30 driver changes), new CPU IDs for the RAPL power capping driver, relatively minor updates of the generic power domains (genpd) and operation performance points (OPP) frameworks, and assorted fixes and cleanups. There are also two maintainer information updates: Chanwoo Choi will be maintaining the devfreq subsystem going forward and Todd Brandt is going to maintain the pm-graph utility (created by him). Specifics: - Use nanoseconds (instead of microseconds) as the unit of time in the cpuidle core and simplify checks for disabled idle states in the idle loop (Rafael Wysocki) - Fix and clean up the teo cpuidle governor (Rafael Wysocki) - Fix the cpuidle registration error code path (Zhenzhong Duan) - Avoid excessive vmexits in the ACPI cpuidle driver (Yin Fengwei) - Extend the idle injection infrastructure to be able to measure the requested duration in nanoseconds and to allow an exit latency limit for idle states to be specified (Daniel Lezcano) - Fix cpufreq driver registration and clarify a comment in the cpufreq core (Viresh Kumar) - Add NULL checks to the show() and store() methods of sysfs attributes exposed by cpufreq (Kai Shen) - Update cpufreq drivers: * Fix for a plain int as pointer warning from sparse in intel_pstate (Jamal Shareef) * Fix for a hardcoded number of CPUs and stack bloat in the powernv driver (John Hubbard) * Updates to the ti-cpufreq driver and DT files to support new platforms and migrate bindings from opp-v1 to opp-v2 (Adam Ford, H. Nikolaus Schaller) * Merging of the arm_big_little and vexpress-spc drivers and related cleanup (Sudeep Holla) * Fix for imx's default speed grade value (Anson Huang) * Minor cleanup of the s3c64xx driver (Nathan Chancellor) * CPU speed bin detection fix for sun50i (Ondrej Jirman) - Appoint Chanwoo Choi as the new devfreq maintainer. - Update the devfreq core: * Check NULL governor in available_governors_show sysfs to prevent showing wrong governor information and fix a race condition between devfreq_update_status() and trans_stat_show() (Leonard Crestez) * Add new 'interrupt-driven' flag for devfreq governors to allow interrupt-driven governors to prevent the devfreq core from polling devices for status (Dmitry Osipenko) * Improve an error message in devfreq_add_device() (Matthias Kaehlcke) - Update devfreq drivers: * tegra30 driver fixes and cleanups (Dmitry Osipenko) * Removal of unused property from dt-binding documentation for the exynos-bus driver (Kamil Konieczny) * exynos-ppmu cleanup and DT bindings update (Lukasz Luba, Marek Szyprowski) - Add new CPU IDs for CometLake Mobile and Desktop to the Intel RAPL power capping driver (Zhang Rui) - Allow device initialization in the generic power domains (genpd) framework to be more straightforward and clean it up (Ulf Hansson) - Add support for adjusting OPP voltages at run time to the OPP framework (Stephen Boyd) - Avoid freeing memory that has never been allocated in the hibernation core (Andy Whitcroft) - Clean up function headers in a header file and coding style in the wakeup IRQs handling code (Ulf Hansson, Xiaofei Tan) - Clean up the SmartReflex adaptive voltage scaling (AVS) driver for ARM (Ben Dooks, Geert Uytterhoeven) - Wrap power management documentation to fit in 80 columns (Bjorn Helgaas) - Add pm-graph utility entry to MAINTAINERS (Todd Brandt) - Update the cpupower utility: * Fix the handling of set and info subcommands (Abhishek Goel) * Fix build warnings (Nathan Chancellor) * Improve mperf_monitor handling (Janakarajan Natarajan)" * tag 'pm-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (83 commits) PM: Wrap documentation to fit in 80 columns cpuidle: Pass exit latency limit to cpuidle_use_deepest_state() cpuidle: Allow idle injection to apply exit latency limit cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks cpuidle: teo: Avoid code duplication in conditionals cpufreq: Register drivers only after CPU devices have been registered cpuidle: teo: Avoid using "early hits" incorrectly cpuidle: teo: Exclude cpuidle overhead from computations PM / Domains: Convert to dev_to_genpd_safe() in genpd_syscore_switch() mmc: tmio: Avoid boilerplate code in ->runtime_suspend() PM / Domains: Implement the ->start() callback for genpd PM / Domains: Introduce dev_pm_domain_start() ARM: OMAP2+: SmartReflex: add omap_sr_pdata definition PM / wakeirq: remove unnecessary parentheses power: avs: smartreflex: Remove superfluous cast in debugfs_create_file() call cpuidle: Use nanoseconds as the unit of time PM / OPP: Support adjusting OPP voltages at runtime PM / core: Clean up some function headers in power.h cpufreq: Add NULL checks to show() and store() methods of cpufreq cpufreq: intel_pstate: Fix plain int as pointer warning from sparse ...

Merge branch 'pm-cpuidle'

2019-11-26T09:26:26+00:00

* pm-cpuidle: cpuidle: Pass exit latency limit to cpuidle_use_deepest_state() cpuidle: Allow idle injection to apply exit latency limit cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks cpuidle: teo: Avoid code duplication in conditionals cpuidle: teo: Avoid using "early hits" incorrectly cpuidle: teo: Exclude cpuidle overhead from computations cpuidle: Use nanoseconds as the unit of time cpuidle: Consolidate disabled state checks ACPI: processor_idle: Skip dummy wait if kernel is in guest cpuidle: Do not unset the driver if it is there already cpuidle: teo: Fix "early hits" handling for disabled idle states cpuidle: teo: Consider hits and misses metrics of disabled states cpuidle: teo: Rename local variable in teo_select() cpuidle: teo: Ignore disabled idle states that are too deep

cpuidle: Pass exit latency limit to cpuidle_use_deepest_state()

2019-11-20T10:46:18+00:00

Modify cpuidle_use_deepest_state() to take an additional exit latency limit argument to be passed to find_deepest_idle_state() and make cpuidle_idle_call() pass dev->forced_idle_latency_limit_ns to it for forced idle. Suggested-by: Rafael J. Wysocki Signed-off-by: Daniel Lezcano [ rjw: Rebase and rearrange code, subject & changelog ] Signed-off-by: Rafael J. Wysocki

cpuidle: Allow idle injection to apply exit latency limit

2019-11-20T10:32:55+00:00

In some cases it may be useful to specify an exit latency limit for the idle state to be used during CPU idle time injection. Instead of duplicating the information in struct cpuidle_device or propagating the latency limit in the call stack, replace the use_deepest_state field with forced_latency_limit_ns to represent that limit, so that the deepest idle state with exit latency within that limit is forced (i.e. no governors) when it is set. A zero exit latency limit for forced idle means to use governors in the usual way (analogous to use_deepest_state equal to "false" before this change). Additionally, add play_idle_precise() taking two arguments, the duration of forced idle and the idle state exit latency limit, both in nanoseconds, and redefine play_idle() as a wrapper around that new function. This change is preparatory, no functional impact is expected. Suggested-by: Rafael J. Wysocki Signed-off-by: Daniel Lezcano [ rjw: Subject, changelog, cpuidle_use_deepest_state() kerneldoc, whitespace ] Signed-off-by: Rafael J. Wysocki

cpuidle: Use nanoseconds as the unit of time

2019-11-11T20:56:07+00:00

Currently, the cpuidle subsystem uses microseconds as the unit of time which (among other things) causes the idle loop to incur some integer division overhead for no clear benefit. In order to allow cpuidle to measure time in nanoseconds, add two new fields, exit_latency_ns and target_residency_ns, to represent the exit latency and target residency of an idle state in nanoseconds, respectively, to struct cpuidle_state and initialize them with the help of the corresponding values in microseconds provided by drivers. Additionally, change cpuidle_governor_latency_req() to return the idle state exit latency constraint in nanoseconds. Also meeasure idle state residency (last_residency_ns in struct cpuidle_device and time_ns in struct cpuidle_driver) in nanoseconds and update the cpuidle core and governors accordingly. However, the menu governor still computes typical intervals in microseconds to avoid integer overflows. Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Doug Smythies Tested-by: Doug Smythies

sched/core: Further clarify sched_class::set_next_task()

2019-11-11T07:35:21+00:00

It turns out there really is something special to the first set_next_task() invocation. In specific the 'change' pattern really should not cause balance callbacks. Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: juri.lelli@redhat.com Cc: ktkhai@virtuozzo.com Cc: mgorman@suse.de Cc: qais.yousef@arm.com Cc: qperret@google.com Cc: rostedt@goodmis.org Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Fixes: f95d4eaee6d0 ("sched/{rt,deadline}: Fix set_next_task vs pick_next_task") Link: https://lkml.kernel.org/r/20191108131909.775434698@infradead.org Signed-off-by: Ingo Molnar