[patch 1/3] timers: use function instead of macro for calc_load

From: Thomas Gleixner
Date: Sat May 02 2009 - 15:08:36 EST


Replace the CALC_LOAD macro by a static function.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/sched.h | 5 -----
kernel/timer.c | 29 ++++++++++++++---------------
2 files changed, 14 insertions(+), 20 deletions(-)

Index: linux-2.6/include/linux/sched.h
===================================================================
--- linux-2.6.orig/include/linux/sched.h
+++ linux-2.6/include/linux/sched.h
@@ -124,11 +124,6 @@ extern unsigned long avenrun[]; /* Load
#define EXP_5 2014 /* 1/exp(5sec/5min) */
#define EXP_15 2037 /* 1/exp(5sec/15min) */

-#define CALC_LOAD(load,exp,n) \
- load *= exp; \
- load += n*(FIXED_1-exp); \
- load >>= FSHIFT;
-
extern unsigned long total_forks;
extern int nr_threads;
DECLARE_PER_CPU(unsigned long, process_counts);
Index: linux-2.6/kernel/timer.c
===================================================================
--- linux-2.6.orig/kernel/timer.c
+++ linux-2.6/kernel/timer.c
@@ -1123,14 +1123,6 @@ void update_process_times(int user_tick)
}

/*
- * Nr of active tasks - counted in fixed-point numbers
- */
-static unsigned long count_active_tasks(void)
-{
- return nr_active() * FIXED_1;
-}
-
-/*
* Hmm.. Changed this, as the GNU make sources (load.c) seems to
* imply that avenrun[] is the standard name for this kind of thing.
* Nothing else seems to be standardized: the fractional size etc
@@ -1139,25 +1131,32 @@ static unsigned long count_active_tasks(
* Requires xtime_lock to access.
*/
unsigned long avenrun[3];
-
EXPORT_SYMBOL(avenrun);

+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+ load *= exp;
+ load += active * (FIXED_1 - exp);
+ return load >> FSHIFT;
+}
+
/*
* calc_load - given tick count, update the avenrun load estimates.
* This is called while holding a write_lock on xtime_lock.
*/
-static inline void calc_load(unsigned long ticks)
+static void calc_global_load(unsigned long ticks)
{
unsigned long active_tasks; /* fixed-point */
static int count = LOAD_FREQ;

count -= ticks;
if (unlikely(count < 0)) {
- active_tasks = count_active_tasks();
+ active_tasks = nr_active() * FIXED_1;
do {
- CALC_LOAD(avenrun[0], EXP_1, active_tasks);
- CALC_LOAD(avenrun[1], EXP_5, active_tasks);
- CALC_LOAD(avenrun[2], EXP_15, active_tasks);
+ avenrun[0] = calc_load(avenrun[0], EXP_1, active_tasks);
+ avenrun[1] = calc_load(avenrun[1], EXP_5, active_tasks);
+ avenrun[2] = calc_load(avenrun[2], EXP_15, active_tasks);
count += LOAD_FREQ;
} while (count < 0);
}
@@ -1193,7 +1192,7 @@ void run_local_timers(void)
static inline void update_times(unsigned long ticks)
{
update_wall_time();
- calc_load(ticks);
+ calc_global_load(ticks);
}

/*


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