1. 16 4月, 2013 2 次提交
    • F
      nohz: Switch from "extended nohz" to "full nohz" based naming · c5bfece2
      Frederic Weisbecker 提交于
      "Extended nohz" was used as a naming base for the full dynticks
      API and Kconfig symbols. It reflects the fact the system tries
      to stop the tick in more places than just idle.
      
      But that "extended" name is a bit opaque and vague. Rename it to
      "full" makes it clearer what the system tries to do under this
      config: try to shutdown the tick anytime it can. The various
      constraints that prevent that to happen shouldn't be considered
      as fundamental properties of this feature but rather technical
      issues that may be solved in the future.
      Reported-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      c5bfece2
    • F
      nohz: Fix old dynticks idle Kconfig backward compatibility · 0644ca5c
      Frederic Weisbecker 提交于
      In order to enforce backward compatibility with older
      config files, we want the new dynticks-idle Kconfig entry
      to default its value to the one of the old CONFIG_NO_HZ symbol
      if present.
      
      Namely we want:
      
      	config NO_HZ # old obsolete dynticks idle symbol
      		bool
      
      	config NO_HZ_IDLE # new dynticks idle symbol
      		default NO_HZ
      
      However Kconfig prevents this to work if the old symbol
      is not visible. And this is currently the case because
      NO_HZ lacks a title in order to show it in make oldconfig
      and alike.
      
      To fix this, bring a minimal title and help text to the
      obsolete Kconfig entry that explains its purpose. This
      makes the "defaulting" to work.
      Reported-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      0644ca5c
  2. 03 4月, 2013 3 次提交
    • F
      nohz: Pack nohz Kconfig option in a menu of choices · 3ca277e4
      Frederic Weisbecker 提交于
      Now the user has the choice between three implementations of
      the timer tick:
      
      * Static periodic tick
      * Idle dynticks
      * Full dynticks
      
      At least for now, these are mutually exclusive choices, so
      let's rely on the proper Kconfig feature to display these
      to the user.
      
      A new entry CONFIG_NO_HZ_IDLE is created and the old
      CONFIG_NO_HZ maps to it for config file backward compatibility.
      The old name was too general now that we have more
      granular dynticks implementations.
      
      While at it, add some explanation to help the user on
      his decision between the 3 entries.
      Reported-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      3ca277e4
    • F
      nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON · 3451d024
      Frederic Weisbecker 提交于
      We are planning to convert the dynticks Kconfig options layout
      into a choice menu. The user must be able to easily pick
      any of the following implementations: constant periodic tick,
      idle dynticks, full dynticks.
      
      As this implies a mutual exclusion, the two dynticks implementions
      need to converge on the selection of a common Kconfig option in order
      to ease the sharing of a common infrastructure.
      
      It would thus seem pretty natural to reuse CONFIG_NO_HZ to
      that end. It already implements all the idle dynticks code
      and the full dynticks depends on all that code for now.
      So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
      CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.
      
      On the other hand we want to stay backward compatible: if
      CONFIG_NO_HZ is set in an older config file, we want to
      enable CONFIG_NO_HZ_IDLE by default.
      
      But we can't afford both at the same time or we run into
      a circular dependency:
      
      1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
         CONFIG_NO_HZ
      2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE
      
      We might be able to support that from Kconfig/Kbuild but it
      may not be wise to introduce such a confusing behaviour.
      
      So to solve this, create a new CONFIG_NO_HZ_COMMON option
      which gathers the common code between idle and full dynticks
      (that common code for now is simply the idle dynticks code)
      and select it from their referring Kconfig.
      
      Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
      to it for backward compatibility.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      3451d024
    • F
      nohz: Unhide full dynticks feature from its dependencies · ab71d36d
      Frederic Weisbecker 提交于
      The full dynticks feature only shows up when all its
      Kconfig dependencies are met (RCU nocbs, RCU user mode, ...)
      
      This is far from being user friendly as those who want to
      activate this feature need to look into the Kconfig files
      and iterate through each dependency then activate these
      by hand in order to show and select the full dynticks
      Kconfig option.
      
      So process the other way around: show up the Kconfig option
      if the minimal low level dependencies are met and activate
      the high level ones when we enable the feature.
      
      Note there is one exception in the picture:
      CONFIG_VIRT_CPU_ACCOUNTING_GEN is part of a Kconfig choice
      menu and it appears we can't select it from another Kconfig
      selection when it's under such layout. So for now this
      particular item stays as a passive dependency.
      Reported-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      ab71d36d
  3. 21 3月, 2013 1 次提交
    • F
      nohz: Basic full dynticks interface · a831881b
      Frederic Weisbecker 提交于
      For extreme usecases such as Real Time or HPC, having
      the ability to shutdown the tick when a single task runs
      on a CPU is a desired feature:
      
      * Reducing the amount of interrupts improves throughput
      for CPU-bound tasks. The CPU is less distracted from its
      real job, from an execution time and from the cache point
      of views.
      
      * This also improve latency response as we have less critical
      sections.
      
      Start with introducing a very simple interface to define
      full dynticks CPU: use a boot time option defined cpumask
      through the "nohz_extended=" kernel parameter. CPUs that
      are part of this range will have their tick shutdown
      whenever possible: provided they run a single task and
      they don't do kernel activity that require the periodic
      tick. These details will be later documented in
      Documentation/*
      
      An online CPU must be kept outside this range to handle the
      timekeeping.
      Suggested-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kevin Hilman <khilman@linaro.org>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Namhyung Kim <namhyung.kim@lge.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      a831881b
  4. 01 2月, 2013 1 次提交
  5. 30 1月, 2013 1 次提交
  6. 16 1月, 2013 1 次提交
    • F
      timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK option · 05ad717c
      Feng Tang 提交于
      Make the persistent clock check a kernel config option, so that some
      platform can explicitely select it, also make CONFIG_RTC_HCTOSYS and
      RTC_SYSTOHC depend on its non-existence, which could prevent the
      persistent clock and RTC code from doing similar thing twice during
      system's init/suspend/resume phases.
      
      If the CONFIG_HAS_PERSISTENT_CLOCK=n, then no change happens for kernel
      which still does the persistent clock check in timekeeping_init().
      
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Suggested-by: NJohn Stultz <john.stultz@linaro.org>
      Signed-off-by: NFeng Tang <feng.tang@intel.com>
      [jstultz: Added dependency for RTC_SYSTOHC as well]
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      05ad717c
  7. 25 9月, 2012 2 次提交
    • J
      time: Introduce new GENERIC_TIME_VSYSCALL · 576094b7
      John Stultz 提交于
      Now that we moved everyone over to GENERIC_TIME_VSYSCALL_OLD,
      introduce the new declaration and config option for the new
      update_vsyscall method.
      
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Turner <pjt@google.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      576094b7
    • J
      time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD · 70639421
      John Stultz 提交于
      To help migrate archtectures over to the new update_vsyscall method,
      redfine CONFIG_GENERIC_TIME_VSYSCALL as CONFIG_GENERIC_TIME_VSYSCALL_OLD
      
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Turner <pjt@google.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      70639421
  8. 22 5月, 2012 1 次提交
    • T
      timers: Fixup the Kconfig consolidation fallout · 764e0da1
      Thomas Gleixner 提交于
      Sigh, I missed to check which architecture Kconfig files actually
      include the core Kconfig file. There are a few which did not. So we
      broke them.
      
      Instead of adding the includes to those, we are better off to move the
      include to init/Kconfig like we did already with irqs and others.
      
      This does not change anything for the architectures using the old
      style periodic timer mode. It just solves the build wreckage there.
      
      For those architectures which use the clock events infrastructure it
      moves the include of the core Kconfig file to "General setup" which is
      a way more logical place than having it at random locations specified
      by the architecture specific Kconfigs.
      Reported-by: NIngo Molnar <mingo@kernel.org>
      Cc: Anna-Maria Gleixner <anna-maria@glx-um.de>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      764e0da1
  9. 21 5月, 2012 1 次提交
  10. 31 3月, 2012 1 次提交
  11. 29 11月, 2011 1 次提交
  12. 08 9月, 2011 1 次提交
  13. 27 7月, 2010 1 次提交
  14. 17 10月, 2008 1 次提交
  15. 13 10月, 2007 1 次提交
  16. 17 2月, 2007 2 次提交