1. 26 10月, 2012 2 次提交
  2. 19 10月, 2012 1 次提交
  3. 18 10月, 2012 2 次提交
  4. 16 10月, 2012 1 次提交
  5. 13 10月, 2012 1 次提交
  6. 12 10月, 2012 1 次提交
  7. 06 10月, 2012 1 次提交
  8. 05 10月, 2012 1 次提交
  9. 04 10月, 2012 3 次提交
  10. 03 10月, 2012 1 次提交
  11. 01 10月, 2012 3 次提交
  12. 28 9月, 2012 3 次提交
  13. 27 9月, 2012 3 次提交
  14. 26 9月, 2012 10 次提交
  15. 25 9月, 2012 4 次提交
    • J
      time: Convert x86_64 to using new update_vsyscall · 650ea024
      John Stultz 提交于
      Switch x86_64 to using sub-ns precise vsyscall
      
      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>
      650ea024
    • 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
    • J
      time: Move update_vsyscall definitions to timekeeper_internal.h · 189374ae
      John Stultz 提交于
      Since users will need to include timekeeper_internal.h, move
      update_vsyscall definitions to timekeeper_internal.h.
      
      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>
      189374ae
    • J
      jiffies: Remove compile time assumptions about CLOCK_TICK_RATE · b3c869d3
      John Stultz 提交于
      CLOCK_TICK_RATE is used to accurately caclulate exactly how
      a tick will be at a given HZ.
      
      This is useful, because while we'd expect NSEC_PER_SEC/HZ,
      the underlying hardware will have some granularity limit,
      so we won't be able to have exactly HZ ticks per second.
      
      This slight error can cause timekeeping quality problems
      when using the jiffies or other jiffies driven clocksources.
      Thus we currently use compile time CLOCK_TICK_RATE value to
      generate SHIFTED_HZ and NSEC_PER_JIFFIES, which we then use
      to adjust the jiffies clocksource to correct this error.
      
      Unfortunately though, since CLOCK_TICK_RATE is a compile
      time value, and the jiffies clocksource is registered very
      early during boot, there are a number of cases where there
      are different possible hardware timers that have different
      tick rates. This causes problems in cases like ARM where
      there are numerous different types of hardware, each having
      their own compile-time CLOCK_TICK_RATE, making it hard to
      accurately support different hardware with a single kernel.
      
      For the most part, this doesn't matter all that much, as not
      too many systems actually utilize the jiffies or jiffies driven
      clocksource. Usually there are other highres clocksources
      who's granularity error is negligable.
      
      Even so, we have some complicated calcualtions that we do
      everywhere to handle these edge cases.
      
      This patch removes the compile time SHIFTED_HZ value, and
      introduces a register_refined_jiffies() function. This results
      in the default jiffies clock as being assumed a perfect HZ
      freq, and allows archtectures that care about jiffies accuracy
      to call register_refined_jiffies() with the tick rate, specified
      dynamically at boot.
      
      This allows us, where necessary, to not have a compile time
      CLOCK_TICK_RATE constant, simplifies the jiffies code, and
      still provides a way to have an accurate jiffies clock.
      
      NOTE: Since this patch does not add register_refinied_jiffies()
      calls for every arch, it may cause time quality regressions
      in some cases. Its likely these will not be noticable, but
      if they are an issue, adding the following to the end of
      setup_arch() should resolve the regression:
      	register_refinied_jiffies(CLOCK_TICK_RATE)
      
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      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>
      b3c869d3
  16. 23 9月, 2012 2 次提交
    • S
      Use get_online_cpus to avoid races involving CPU hotplug · 429227bb
      Silas Boyd-Wickizer 提交于
      If arch/x86/kernel/cpuid.c is a module, a CPU might offline or online
      between the for_each_online_cpu() loop and the call to
      register_hotcpu_notifier in cpuid_init or the call to
      unregister_hotcpu_notifier in cpuid_exit.  The potential races can
      lead to leaks/duplicates, attempts to destroy non-existant devices, or
      random pointer dereferences.
      
      For example, in cpuid_exit if:
      
              for_each_online_cpu(cpu)
                      cpuid_device_destroy(cpu);
              class_destroy(cpuid_class);
              __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
              <----- CPU onlines
              unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);
      
      the hotcpu notifier will attempt to create a device for the
      cpuid_class, which the module already destroyed.
      
      This fix surrounds for_each_online_cpu and register_hotcpu_notifier or
      unregister_hotcpu_notifier with get_online_cpus+put_online_cpus.
      
      Tested on a VM.
      Signed-off-by: NSilas Boyd-Wickizer <sbw@mit.edu>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      429227bb
    • S
      Use get_online_cpus to avoid races involving CPU hotplug · a2db672a
      Silas Boyd-Wickizer 提交于
      If arch/x86/kernel/msr.c is a module, a CPU might offline or online
      between the for_each_online_cpu(i) loop and the call to
      register_hotcpu_notifier in msr_init or the call to
      unregister_hotcpu_notifier in msr_exit. The potential races can lead
      to leaks/duplicates, attempts to destroy non-existant devices, or
      random pointer dereferences.
      
      For example, in msr_init if:
      
              for_each_online_cpu(i) {
                      err = msr_device_create(i);
                      if (err != 0)
                              goto out_class;
              }
              <----- CPU offlines
              register_hotcpu_notifier(&msr_class_cpu_notifier);
      
      and the CPU never onlines before msr_exit, then the module will never
      call msr_device_destroy for the associated CPU.
      
      This fix surrounds for_each_online_cpu and register_hotcpu_notifier or
      unregister_hotcpu_notifier with get_online_cpus+put_online_cpus.
      
      Tested on a VM.
      Signed-off-by: NSilas Boyd-Wickizer <sbw@mit.edu>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      a2db672a
  17. 22 9月, 2012 1 次提交
    • S
      x86, kvm: fix kvm's usage of kernel_fpu_begin/end() · b1a74bf8
      Suresh Siddha 提交于
      Preemption is disabled between kernel_fpu_begin/end() and as such
      it is not a good idea to use these routines in kvm_load/put_guest_fpu()
      which can be very far apart.
      
      kvm_load/put_guest_fpu() routines are already called with
      preemption disabled and KVM already uses the preempt notifier to save
      the guest fpu state using kvm_put_guest_fpu().
      
      So introduce __kernel_fpu_begin/end() routines which don't touch
      preemption and use them instead of kernel_fpu_begin/end()
      for KVM's use model of saving/restoring guest FPU state.
      
      Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit
      state in the case of VMX. For eagerFPU case, host cr0.TS is always clear.
      So no need to worry about it. For the traditional lazyFPU restore case,
      change the cr0.TS bit for the host state during vm-exit to be always clear
      and cr0.TS bit is set in the __vmx_load_host_state() when the FPU
      (guest FPU or the host task's FPU) state is not active. This ensures
      that the host/guest FPU state is properly saved, restored
      during context-switch and with interrupts (using irq_fpu_usable()) not
      stomping on the active FPU state.
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
      Cc: Avi Kivity <avi@redhat.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      b1a74bf8