Now that the decaying cpu load stat indexes used by LB_BIAS are ignored in full dynticks mode, let's conditionally build that code to optimize the off case.
Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Li Zhong <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Alex Shi <[email protected]> Cc: Paul Turner <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Vincent Guittot <[email protected]> --- kernel/sched/proc.c | 45 ++++++++++++++++++++++++++++----------------- kernel/sched/sched.h | 4 ++++ 2 files changed, 32 insertions(+), 17 deletions(-) diff --git a/kernel/sched/proc.c b/kernel/sched/proc.c index 030528a..34920e4 100644 --- a/kernel/sched/proc.c +++ b/kernel/sched/proc.c @@ -394,6 +394,7 @@ static void calc_load_account_active(struct rq *this_rq) this_rq->calc_load_update += LOAD_FREQ; } +#ifdef CONFIG_NO_HZ_IDLE /* * End of global load-average stuff */ @@ -465,26 +466,13 @@ decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) return load; } -/* - * Update rq->cpu_load[] statistics. This function is usually called every - * scheduler tick (TICK_NSEC). With tickless idle this will not be called - * every tick. We fix it up based on jiffies. - */ -static void __update_cpu_load(struct rq *this_rq, unsigned long this_load) +static void update_cpu_load_decayed(struct rq *this_rq, unsigned long this_load, + unsigned long pending_updates) { - unsigned long curr_jiffies = ACCESS_ONCE(jiffies); - unsigned long pending_updates; int i, scale; + unsigned long old_load, new_load; - pending_updates = curr_jiffies - this_rq->last_load_update_tick; - this_rq->last_load_update_tick = curr_jiffies; - this_rq->nr_load_updates++; - - /* Update our load: */ - this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { - unsigned long old_load, new_load; - /* scale is effectively 1 << i now, and >> i divides by scale */ old_load = this_rq->cpu_load[i]; @@ -500,6 +488,30 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load) this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; } +} +#else /* CONFIG_NO_HZ_IDLE */ +static inline void update_cpu_load_decayed(struct rq *this_rq, unsigned long this_load, + unsigned long pending_updates) +{ } +#endif + +/* + * Update rq->cpu_load[] statistics. This function is usually called every + * scheduler tick (TICK_NSEC). With tickless idle this will not be called + * every tick. We fix it up based on jiffies. + */ +static void __update_cpu_load(struct rq *this_rq, unsigned long this_load) +{ + unsigned long curr_jiffies = ACCESS_ONCE(jiffies); + unsigned long pending_updates; + + pending_updates = curr_jiffies - this_rq->last_load_update_tick; + this_rq->last_load_update_tick = curr_jiffies; + this_rq->nr_load_updates++; + + /* Update our load: */ + this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ + update_cpu_load_decayed(this_rq, this_load, pending_updates); sched_avg_update(this_rq); } @@ -561,6 +573,5 @@ void update_cpu_load_nohz(void) void update_cpu_load_active(struct rq *this_rq) { __update_cpu_load(this_rq, this_rq->load.weight); - calc_load_account_active(this_rq); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 029601a..ffa241df 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -410,7 +410,11 @@ struct rq { * remote CPUs use both these fields when doing load calculation. */ unsigned int nr_running; +#ifdef CONFIG_NO_HZ_IDLE #define CPU_LOAD_IDX_MAX 5 +#else + #define CPU_LOAD_IDX_MAX 1 +#endif unsigned long cpu_load[CPU_LOAD_IDX_MAX]; unsigned long last_load_update_tick; #ifdef CONFIG_NO_HZ_COMMON -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
