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

Dimitri Sivanich
2009-05-07T18:16:19Z

On Sat, May 02, 2009 at 07:06:31PM -0000, Thomas Gleixner wrote:
> Replace the CALC_LOAD macro by a static function.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
> ---
> 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);
> }
>
> /*
>