• Linus Torvalds's avatar
    Merge tag 'pm+acpi-4.6-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 277edbab
    Linus Torvalds authored
    Pull power management and ACPI updates from Rafael Wysocki:
     "This time the majority of changes go into cpufreq and they are
      significant.
    
      First off, the way CPU frequency updates are triggered is different
      now.  Instead of having to set up and manage a deferrable timer for
      each CPU in the system to evaluate and possibly change its frequency
      periodically, cpufreq governors set up callbacks to be invoked by the
      scheduler on a regular basis (basically on utilization updates).  The
      "old" governors, "ondemand" and "conservative", still do all of their
      work in process context (although that is triggered by the scheduler
      now), but intel_pstate does it all in the callback invoked by the
      scheduler with no need for any additional asynchronous processing.
    
      Of course, this eliminates the overhead related to the management of
      all those timers, but also it allows the cpufreq governor code to be
      simplified quite a bit.  On top of that, the common code and data
      structures used by the "ondemand" and "conservative" governors are
      cleaned up and made more straightforward and some long-standing and
      quite annoying problems are addressed.  In particular, the handling of
      governor sysfs attributes is modified and the related locking becomes
      more fine grained which allows some concurrency problems to be avoided
      (particularly deadlocks with the core cpufreq code).
    
      In principle, the new mechanism for triggering frequency updates
      allows utilization information to be passed from the scheduler to
      cpufreq.  Although the current code doesn't make use of it, in the
      works is a new cpufreq governor that will make decisions based on the
      scheduler's utilization data.  That should allow the scheduler and
      cpufreq to work more closely together in the long run.
    
      In addition to the core and governor changes, cpufreq drivers are
      updated too.  Fixes and optimizations go into intel_pstate, the
      cpufreq-dt driver is updated on top of some modification in the
      Operating Performance Points (OPP) framework and there are fixes and
      other updates in the powernv cpufreq driver.
    
      Apart from the cpufreq updates there is some new ACPICA material,
      including a fix for a problem introduced by previous ACPICA updates,
      and some less significant changes in the ACPI code, like CPPC code
      optimizations, ACPI processor driver cleanups and support for loading
      ACPI tables from initrd.
    
      Also updated are the generic power domains framework, the Intel RAPL
      power capping driver and the turbostat utility and we have a bunch of
      traditional assorted fixes and cleanups.
    
      Specifics:
    
       - Redesign of cpufreq governors and the intel_pstate driver to make
         them use callbacks invoked by the scheduler to trigger CPU
         frequency evaluation instead of using per-CPU deferrable timers for
         that purpose (Rafael Wysocki).
    
       - Reorganization and cleanup of cpufreq governor code to make it more
         straightforward and fix some concurrency problems in it (Rafael
         Wysocki, Viresh Kumar).
    
       - Cleanup and improvements of locking in the cpufreq core (Viresh
         Kumar).
    
       - Assorted cleanups in the cpufreq core (Rafael Wysocki, Viresh
         Kumar, Eric Biggers).
    
       - intel_pstate driver updates including fixes, optimizations and a
         modification to make it enable enable hardware-coordinated P-state
         selection (HWP) by default if supported by the processor (Philippe
         Longepe, Srinivas Pandruvada, Rafael Wysocki, Viresh Kumar, Felipe
         Franciosi).
    
       - Operating Performance Points (OPP) framework updates to improve its
         handling of voltage regulators and device clocks and updates of the
         cpufreq-dt driver on top of that (Viresh Kumar, Jon Hunter).
    
       - Updates of the powernv cpufreq driver to fix initialization and
         cleanup problems in it and correct its worker thread handling with
         respect to CPU offline, new powernv_throttle tracepoint (Shilpasri
         Bhat).
    
       - ACPI cpufreq driver optimization and cleanup (Rafael Wysocki).
    
       - ACPICA updates including one fix for a regression introduced by
         previos changes in the ACPICA code (Bob Moore, Lv Zheng, David Box,
         Colin Ian King).
    
       - Support for installing ACPI tables from initrd (Lv Zheng).
    
       - Optimizations of the ACPI CPPC code (Prashanth Prakash, Ashwin
         Chaugule).
    
       - Support for _HID(ACPI0010) devices (ACPI processor containers) and
         ACPI processor driver cleanups (Sudeep Holla).
    
       - Support for ACPI-based enumeration of the AMBA bus (Graeme Gregory,
         Aleksey Makarov).
    
       - Modification of the ACPI PCI IRQ management code to make it treat
         255 in the Interrupt Line register as "not connected" on x86 (as
         per the specification) and avoid attempts to use that value as a
         valid interrupt vector (Chen Fan).
    
       - ACPI APEI fixes related to resource leaks (Josh Hunt).
    
       - Removal of modularity from a few ACPI drivers (BGRT, GHES,
         intel_pmic_crc) that cannot be built as modules in practice (Paul
         Gortmaker).
    
       - PNP framework update to make it treat ACPI_RESOURCE_TYPE_SERIAL_BUS
         as a valid resource type (Harb Abdulhamid).
    
       - New device ID (future AMD I2C controller) in the ACPI driver for
         AMD SoCs (APD) and in the designware I2C driver (Xiangliang Yu).
    
       - Assorted ACPI cleanups (Colin Ian King, Kaiyen Chang, Oleg Drokin).
    
       - cpuidle menu governor optimization to avoid a square root
         computation in it (Rasmus Villemoes).
    
       - Fix for potential use-after-free in the generic device properties
         framework (Heikki Krogerus).
    
       - Updates of the generic power domains (genpd) framework including
         support for multiple power states of a domain, fixes and debugfs
         output improvements (Axel Haslam, Jon Hunter, Laurent Pinchart,
         Geert Uytterhoeven).
    
       - Intel RAPL power capping driver updates to reduce IPI overhead in
         it (Jacob Pan).
    
       - System suspend/hibernation code cleanups (Eric Biggers, Saurabh
         Sengar).
    
       - Year 2038 fix for the process freezer (Abhilash Jindal).
    
       - turbostat utility updates including new features (decoding of more
         registers and CPUID fields, sub-second intervals support, GFX MHz
         and RC6 printout, --out command line option), fixes (syscall jitter
         detection and workaround, reductioin of the number of syscalls
         made, fixes related to Xeon x200 processors, compiler warning
         fixes) and cleanups (Len Brown, Hubert Chrzaniuk, Chen Yu)"
    
    * tag 'pm+acpi-4.6-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (182 commits)
      tools/power turbostat: bugfix: TDP MSRs print bits fixing
      tools/power turbostat: correct output for MSR_NHM_SNB_PKG_CST_CFG_CTL dump
      tools/power turbostat: call __cpuid() instead of __get_cpuid()
      tools/power turbostat: indicate SMX and SGX support
      tools/power turbostat: detect and work around syscall jitter
      tools/power turbostat: show GFX%rc6
      tools/power turbostat: show GFXMHz
      tools/power turbostat: show IRQs per CPU
      tools/power turbostat: make fewer systems calls
      tools/power turbostat: fix compiler warnings
      tools/power turbostat: add --out option for saving output in a file
      tools/power turbostat: re-name "%Busy" field to "Busy%"
      tools/power turbostat: Intel Xeon x200: fix turbo-ratio decoding
      tools/power turbostat: Intel Xeon x200: fix erroneous bclk value
      tools/power turbostat: allow sub-sec intervals
      ACPI / APEI: ERST: Fixed leaked resources in erst_init
      ACPI / APEI: Fix leaked resources
      intel_pstate: Do not skip samples partially
      intel_pstate: Remove freq calculation from intel_pstate_calc_busy()
      intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()
      ...
    277edbab
sched.h 46.7 KB