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>

2 files changed, 10 insertions, 22 deletions

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 9702fa92489e..156ad803d5b7 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 c1c544513e8d..1f8244a78bee 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;
         }