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  1. 20 9月, 2007 11 次提交
  3. 17 9月, 2007 24 次提交
  5. 16 9月, 2007 5 次提交
    • T
      clockevents: prevent stale tick update on offline cpu · 5e41d0d6
      由 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
    • T
      clockevents: do not shutdown the oneshot broadcast device · 31d9b393
      由 Thomas Gleixner 提交于 
      When a cpu goes offline it is removed from the broadcast masks. If the
mask becomes empty the code shuts down the broadcast device. This is
wrong, because the broadcast device needs to be ready for the online
cpu going idle (into a c-state, which stops the local apic timer).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      31d9b393
    • T
      clockevents: Enforce oneshot broadcast when broadcast mask is set on resume · 07eec6af
      由 Thomas Gleixner 提交于 
      The jinxed VAIO refuses to resume without hitting keys on the keyboard
when this is not enforced. It is unclear why the cpu ends up in a lower
C State without notifying the clock events layer, but enforcing the
oneshot broadcast here is safe.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      07eec6af
    • V
      ACPI: Reevaluate C/P/T states when a cpu becomes online · 729c6ba3
      由 Venkatesh Pallipadi 提交于 
      Reevaluate C/P/T states when a cpu becomes online. This avoids
the caching of the broadcast information in the clockevents layer.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <len.brown@intel.com>
      729c6ba3
    • T
      timekeeping: Prevent time going backwards on resume · 6a669ee8
      由 Thomas Gleixner 提交于 
      Timekeeping resume adjusts xtime by adding the slept time in seconds and
resets the reference value of the clock source (clock->cycle_last).
clock->cycle last is used to calculate the delta between the last xtime
update and the readout of the clock source in __get_nsec_offset(). xtime
plus the offset is the current time. The resume code ignores the delta
which had already elapsed between the last xtime update and the actual
time of suspend. If the suspend time is short, then we can see time
going backwards on resume.

Suspend:
offs_s = clock->read() - clock->cycle_last;
now = xtime + offs_s;
timekeeping_suspend_time = read_rtc();

Resume:
sleep_time = read_rtc() - timekeeping_suspend_time;
xtime.tv_sec += sleep_time;
clock->cycle_last = clock->read();
offs_r = clock->read() - clock->cycle_last;
now = xtime + offs_r;

if sleep_time_seconds == 0 and offs_r < offs_s, then time goes
backwards.

Fix this by storing the offset from the last xtime update and add it to
xtime during resume, when we reset clock->cycle_last:

sleep_time = read_rtc() - timekeeping_suspend_time;
xtime.tv_sec += sleep_time;
xtime += offs_s;	/* Fixup xtime offset at suspend time */
clock->cycle_last = clock->read();
offs_r = clock->read() - clock->cycle_last;
now = xtime + offs_r;

Thanks to Marcelo for tracking this down on the OLPC and providing the
necessary details to analyze the root cause.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Tosatti <marcelo@kvack.org>
      6a669ee8