ia64: Switch do_timer() to xtime_update()

local_cpu_data->itm_next = new_itm; does not need to be protected by
xtime_lock. xtime_update() takes the lock itself.

Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: johnstul@us.ibm.com
Cc: hch@infradead.org
Cc: yong.zhang0@gmail.com
LKML-Reference: <20110127145956.23248.49107.stgit@localhost>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Torben Hohn 2011-01-27 15:59:56 +01:00 committed by Thomas Gleixner
parent daad8b581e
commit 1aabd67d2e
2 changed files with 10 additions and 22 deletions

View file

@ -190,19 +190,10 @@ timer_interrupt (int irq, void *dev_id)
new_itm += local_cpu_data->itm_delta;
if (smp_processor_id() == time_keeper_id) {
/*
* Here we are in the timer irq handler. We have irqs locally
* disabled, but we don't know if the timer_bh is running on
* another CPU. We need to avoid to SMP race by acquiring the
* xtime_lock.
*/
write_seqlock(&xtime_lock);
do_timer(1);
local_cpu_data->itm_next = new_itm;
write_sequnlock(&xtime_lock);
} else
local_cpu_data->itm_next = new_itm;
if (smp_processor_id() == time_keeper_id)
xtime_update(1);
local_cpu_data->itm_next = new_itm;
if (time_after(new_itm, ia64_get_itc()))
break;
@ -222,7 +213,7 @@ timer_interrupt (int irq, void *dev_id)
* comfort, we increase the safety margin by
* intentionally dropping the next tick(s). We do NOT
* update itm.next because that would force us to call
* do_timer() which in turn would let our clock run
* xtime_update() which in turn would let our clock run
* too fast (with the potentially devastating effect
* of losing monotony of time).
*/

View file

@ -139,14 +139,11 @@ consider_steal_time(unsigned long new_itm)
run_posix_cpu_timers(p);
delta_itm += local_cpu_data->itm_delta * (stolen + blocked);
if (cpu == time_keeper_id) {
write_seqlock(&xtime_lock);
do_timer(stolen + blocked);
local_cpu_data->itm_next = delta_itm + new_itm;
write_sequnlock(&xtime_lock);
} else {
local_cpu_data->itm_next = delta_itm + new_itm;
}
if (cpu == time_keeper_id)
xtime_update(stolen + blocked);
local_cpu_data->itm_next = delta_itm + new_itm;
per_cpu(xen_stolen_time, cpu) += NS_PER_TICK * stolen;
per_cpu(xen_blocked_time, cpu) += NS_PER_TICK * blocked;
}