lkml.org 
[lkml]   [2011]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH v2 13/20] ia64: switch do_timer() to xtime_update()
From
Date
local_cpu_data->itm_next = new_itm;  does not need to be protected
by this lock. and xtime_update() takes the lock itself.


Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Torben Hohn <torbenh@gmx.de>
---
arch/ia64/kernel/time.c | 19 +++++--------------
arch/ia64/xen/time.c | 13 +++++--------
2 files changed, 10 insertions(+), 22 deletions(-)
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 9702fa9..156ad80 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -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 @@ skip_process_time_accounting:
* 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).
*/
diff --git a/arch/ia64/xen/time.c b/arch/ia64/xen/time.c
index c1c5445..1f8244a 100644
--- a/arch/ia64/xen/time.c
+++ b/arch/ia64/xen/time.c
@@ -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;
}


\
 
 \ /
  Last update: 2011-01-27 16:15    [from the cache]
©2003-2011 Jasper Spaans