1. 16 9月, 2007 1 次提交
    • T
      clockevents: prevent stale tick update on offline cpu · 5e41d0d6
      Thomas Gleixner 提交于
      Taking a cpu offline removes the cpu from the online mask before the
      CPU_DEAD notification is done. The clock events layer does the cleanup
      of the dead CPU from the CPU_DEAD notifier chain. tick_do_timer_cpu is
      used to avoid xtime lock contention by assigning the task of jiffies
      xtime updates to one CPU. If a CPU is taken offline, then this
      assignment becomes stale. This went unnoticed because most of the time
      the offline CPU went dead before the online CPU reached __cpu_die(),
      where the CPU_DEAD state is checked. In the case that the offline CPU did
      not reach the DEAD state before we reach __cpu_die(), the code in there
      goes to sleep for 100ms. Due to the stale time update assignment, the
      system is stuck forever.
      
      Take the assignment away when a cpu is not longer in the cpu_online_mask.
      We do this in the last call to tick_nohz_stop_sched_tick() when the offline
      CPU is on the way to the final play_dead() idle entry.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      5e41d0d6
  2. 22 7月, 2007 1 次提交
  3. 30 5月, 2007 1 次提交
  4. 24 5月, 2007 1 次提交
  5. 09 5月, 2007 2 次提交
    • S
      sched: dynticks idle load balancing · 46cb4b7c
      Siddha, Suresh B 提交于
      Fix the process idle load balancing in the presence of dynticks.  cpus for
      which ticks are stopped will sleep till the next event wakes it up.
      Potentially these sleeps can be for large durations and during which today,
      there is no periodic idle load balancing being done.
      
      This patch nominates an owner among the idle cpus, which does the idle load
      balancing on behalf of the other idle cpus.  And once all the cpus are
      completely idle, then we can stop this idle load balancing too.  Checks added
      in fast path are minimized.  Whenever there are busy cpus in the system, there
      will be an owner(idle cpu) doing the system wide idle load balancing.
      
      Open items:
      1. Intelligent owner selection (like an idle core in a busy package).
      2. Merge with rcu's nohz_cpu_mask?
      Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
      Acked-by: NIngo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      46cb4b7c
    • T
      highres/dyntick: prevent xtime lock contention · d3ed7824
      Thomas Gleixner 提交于
      While the !highres/!dyntick code assigns the duty of the do_timer() call to
      one specific CPU, this was dropped in the highres/dyntick part during
      development.
      
      Steven Rostedt discovered the xtime lock contention on highres/dyntick due
      to several CPUs trying to update jiffies.
      
      Add the single CPU assignement back.  In the dyntick case this needs to be
      handled carefully, as the CPU which has the do_timer() duty must drop the
      assignement and let it be grabbed by another CPU, which is active.
      Otherwise the do_timer() calls would not happen during the long sleep.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NIngo Molnar <mingo@elte.hu>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Acked-by: NMark Lord <mlord@pobox.com>
      Cc: <stable@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d3ed7824
  6. 27 2月, 2007 1 次提交
  7. 20 2月, 2007 2 次提交
  8. 17 2月, 2007 2 次提交
    • I
      [PATCH] Add debugging feature /proc/timer_list · 289f480a
      Ingo Molnar 提交于
      add /proc/timer_list, which prints all currently pending (high-res) timers,
      all clock-event sources and their parameters in a human-readable form.
      
      Sample output:
      
      Timer List Version: v0.1
      HRTIMER_MAX_CLOCK_BASES: 2
      now at 4246046273872 nsecs
      
      cpu: 0
       clock 0:
        .index:      0
        .resolution: 1 nsecs
        .get_time:   ktime_get_real
        .offset:     1273998312645738432 nsecs
      active timers:
       clock 1:
        .index:      1
        .resolution: 1 nsecs
        .get_time:   ktime_get
        .offset:     0 nsecs
      active timers:
       #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_stop_sched_tick, swapper/0
       # expires at 4246432689566 nsecs [in 386415694 nsecs]
       #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, pcscd/2050
       # expires at 4247018194689 nsecs [in 971920817 nsecs]
       #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, irqbalance/1909
       # expires at 4247351358392 nsecs [in 1305084520 nsecs]
       #3: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, crond/2157
       # expires at 4249097614968 nsecs [in 3051341096 nsecs]
       #4: <f5a90ec8>, it_real_fn, do_setitimer, syslogd/1888
       # expires at 4251329900926 nsecs [in 5283627054 nsecs]
        .expires_next   : 4246432689566 nsecs
        .hres_active    : 1
        .check_clocks   : 0
        .nr_events      : 31306
        .idle_tick      : 4246020791890 nsecs
        .tick_stopped   : 1
        .idle_jiffies   : 986504
        .idle_calls     : 40700
        .idle_sleeps    : 36014
        .idle_entrytime : 4246019418883 nsecs
        .idle_sleeptime : 4178181972709 nsecs
      
      cpu: 1
       clock 0:
        .index:      0
        .resolution: 1 nsecs
        .get_time:   ktime_get_real
        .offset:     1273998312645738432 nsecs
      active timers:
       clock 1:
        .index:      1
        .resolution: 1 nsecs
        .get_time:   ktime_get
        .offset:     0 nsecs
      active timers:
       #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_restart_sched_tick, swapper/0
       # expires at 4246050084568 nsecs [in 3810696 nsecs]
       #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, atd/2227
       # expires at 4261010635003 nsecs [in 14964361131 nsecs]
       #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, smartd/2332
       # expires at 5469485798970 nsecs [in 1223439525098 nsecs]
        .expires_next   : 4246050084568 nsecs
        .hres_active    : 1
        .check_clocks   : 0
        .nr_events      : 24043
        .idle_tick      : 4246046084568 nsecs
        .tick_stopped   : 0
        .idle_jiffies   : 986510
        .idle_calls     : 26360
        .idle_sleeps    : 22551
        .idle_entrytime : 4246043874339 nsecs
        .idle_sleeptime : 4170763761184 nsecs
      
      tick_broadcast_mask: 00000003
      event_broadcast_mask: 00000001
      
      CPU#0's local event device:
      
      Clock Event Device: lapic
       capabilities:   0000000e
       max_delta_ns:   807385544
       min_delta_ns:   1443
       mult:           44624025
       shift:          32
       set_next_event: lapic_next_event
       set_mode:       lapic_timer_setup
       event_handler:  hrtimer_interrupt
        .installed:  1
        .expires:    4246432689566 nsecs
      
      CPU#1's local event device:
      
      Clock Event Device: lapic
       capabilities:   0000000e
       max_delta_ns:   807385544
       min_delta_ns:   1443
       mult:           44624025
       shift:          32
       set_next_event: lapic_next_event
       set_mode:       lapic_timer_setup
       event_handler:  hrtimer_interrupt
        .installed:  1
        .expires:    4246050084568 nsecs
      
      Clock Event Device: hpet
       capabilities:   00000007
       max_delta_ns:   2147483647
       min_delta_ns:   3352
       mult:           61496110
       shift:          32
       set_next_event: hpet_next_event
       set_mode:       hpet_set_mode
       event_handler:  handle_nextevt_broadcast
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: john stultz <johnstul@us.ibm.com>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      289f480a
    • T
      [PATCH] tick-management: dyntick / highres functionality · 79bf2bb3
      Thomas Gleixner 提交于
      With Ingo Molnar <mingo@elte.hu>
      
      Add functions to provide dynamic ticks and high resolution timers.  The code
      which keeps track of jiffies and handles the long idle periods is shared
      between tick based and high resolution timer based dynticks.  The dyntick
      functionality can be disabled on the kernel commandline.  Provide also the
      infrastructure to support high resolution timers.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Cc: john stultz <johnstul@us.ibm.com>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      79bf2bb3