ACPI: Eliminate us to pm ticks conversion in common path
Venkatesh Pallipadi [Wed, 2 Jun 2010 17:01:09 +0000 (10:01 -0700)]
acpi_enter_[simple|bm] routines does us to pm tick conversion on every
idle wakeup and the value is only used in /proc/acpi display. We can
store the time in us and convert it into pm ticks before printing instead and
avoid the conversion in the common path.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/processor_idle.c

index 6b38a6b..b1b3856 100644 (file)
@@ -80,7 +80,7 @@ module_param(nocst, uint, 0000);
 static unsigned int latency_factor __read_mostly = 2;
 module_param(latency_factor, uint, 0644);
 
-static s64 us_to_pm_timer_ticks(s64 t)
+static u64 us_to_pm_timer_ticks(s64 t)
 {
        return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
 }
@@ -731,10 +731,10 @@ static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 
                seq_puts(seq, "demotion[--] ");
 
-               seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
+               seq_printf(seq, "latency[%03d] usage[%08d] duration[%020Lu]\n",
                           pr->power.states[i].latency,
                           pr->power.states[i].usage,
-                          (unsigned long long)pr->power.states[i].time);
+                          us_to_pm_timer_ticks(pr->power.states[i].time));
        }
 
       end:
@@ -861,7 +861,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
        ktime_t  kt1, kt2;
        s64 idle_time_ns;
        s64 idle_time;
-       s64 sleep_ticks = 0;
 
        pr = __get_cpu_var(processors);
 
@@ -906,8 +905,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
        idle_time = idle_time_ns;
        do_div(idle_time, NSEC_PER_USEC);
 
-       sleep_ticks = us_to_pm_timer_ticks(idle_time);
-
        /* Tell the scheduler how much we idled: */
        sched_clock_idle_wakeup_event(idle_time_ns);
 
@@ -918,7 +915,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
        cx->usage++;
 
        lapic_timer_state_broadcast(pr, cx, 0);
-       cx->time += sleep_ticks;
+       cx->time += idle_time;
        return idle_time;
 }
 
@@ -940,7 +937,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
        ktime_t  kt1, kt2;
        s64 idle_time_ns;
        s64 idle_time;
-       s64 sleep_ticks = 0;
 
 
        pr = __get_cpu_var(processors);
@@ -1026,7 +1022,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
        idle_time = idle_time_ns;
        do_div(idle_time, NSEC_PER_USEC);
 
-       sleep_ticks = us_to_pm_timer_ticks(idle_time);
        /* Tell the scheduler how much we idled: */
        sched_clock_idle_wakeup_event(idle_time_ns);
 
@@ -1037,7 +1032,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
        cx->usage++;
 
        lapic_timer_state_broadcast(pr, cx, 0);
-       cx->time += sleep_ticks;
+       cx->time += idle_time;
        return idle_time;
 }