First of all, with CONFIG_NO_HZ_COMMON is disabled, we don't need to call cfs_rq_has_blocked() and others_have_blocked(). And the local variable 'done' is unnecessary as well.
So we put the functions in the #ifdef block so that compiler can help us optimize the code(e.g. the local variable 'done' and the function call). After do that, we introduce a function named update_rq_blocked_load() to remove #ifdef from update_blocked_averages(), which can make the code clean. Second, there are some the same function call in update_blocked_averages() regardless of whether CONFIG_FAIR_GROUP_SCHED is enabled or not. That is rt, dl and irq's load_avg update. So let the update_others_load_avg() do it. Signed-off-by: Muchun Song <smuc...@gmail.com> --- kernel/sched/fair.c | 59 +++++++++++++++++++++++++++++---------------- 1 file changed, 38 insertions(+), 21 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index e30dea59d215..89b3b4a18eee 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7367,6 +7367,7 @@ static void attach_tasks(struct lb_env *env) rq_unlock(env->dst_rq, &rf); } +#ifdef CONFIG_NO_HZ_COMMON static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) { if (cfs_rq->avg.load_avg) @@ -7394,6 +7395,37 @@ static inline bool others_have_blocked(struct rq *rq) return false; } +static inline void update_rq_blocked_load(struct rq *rq, bool clear) +{ + rq->last_blocked_load_update_tick = jiffies; + if (clear) + rq->has_blocked_load = 0; +} +#else /* !CONFIG_NO_HZ_COMMON */ +static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) +{ + return false; +} + +static inline bool others_have_blocked(struct rq *rq) +{ + return false; +} + +static inline void update_rq_blocked_load(struct rq *rq, bool clear) +{ +} +#endif /* CONFIG_NO_HZ_COMMON */ + +static void update_others_load_avg(struct rq *rq) +{ + const struct sched_class *curr = rq->curr->sched_class; + + update_rt_rq_load_avg(rq_clock_task(rq), rq, curr == &rt_sched_class); + update_dl_rq_load_avg(rq_clock_task(rq), rq, curr == &dl_sched_class); + update_irq_load_avg(rq, 0); +} + #ifdef CONFIG_FAIR_GROUP_SCHED static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) @@ -7417,7 +7449,6 @@ static void update_blocked_averages(int cpu) { struct rq *rq = cpu_rq(cpu); struct cfs_rq *cfs_rq, *pos; - const struct sched_class *curr_class; struct rq_flags rf; bool done = true; @@ -7455,19 +7486,12 @@ static void update_blocked_averages(int cpu) done = false; } - curr_class = rq->curr->sched_class; - update_rt_rq_load_avg(rq_clock_task(rq), rq, curr_class == &rt_sched_class); - update_dl_rq_load_avg(rq_clock_task(rq), rq, curr_class == &dl_sched_class); - update_irq_load_avg(rq, 0); + update_others_load_avg(rq); /* Don't need periodic decay once load/util_avg are null */ - if (others_have_blocked(rq)) + if (done && others_have_blocked(rq)) done = false; -#ifdef CONFIG_NO_HZ_COMMON - rq->last_blocked_load_update_tick = jiffies; - if (done) - rq->has_blocked_load = 0; -#endif + update_rq_blocked_load(rq, done); rq_unlock_irqrestore(rq, &rf); } @@ -7522,22 +7546,15 @@ static inline void update_blocked_averages(int cpu) { struct rq *rq = cpu_rq(cpu); struct cfs_rq *cfs_rq = &rq->cfs; - const struct sched_class *curr_class; struct rq_flags rf; rq_lock_irqsave(rq, &rf); update_rq_clock(rq); update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq); - curr_class = rq->curr->sched_class; - update_rt_rq_load_avg(rq_clock_task(rq), rq, curr_class == &rt_sched_class); - update_dl_rq_load_avg(rq_clock_task(rq), rq, curr_class == &dl_sched_class); - update_irq_load_avg(rq, 0); -#ifdef CONFIG_NO_HZ_COMMON - rq->last_blocked_load_update_tick = jiffies; - if (!cfs_rq_has_blocked(cfs_rq) && !others_have_blocked(rq)) - rq->has_blocked_load = 0; -#endif + update_others_load_avg(rq); + update_rq_blocked_load(rq, !cfs_rq_has_blocked(cfs_rq) && + !others_have_blocked(rq)); rq_unlock_irqrestore(rq, &rf); } -- 2.17.1