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[Xen-devel] [PATCH v2 1/2] xen: sched: rtds code clean-up

From: Tianyang Chen <tiche@xxxxxxxxxxxxx>

Date: Sat, 25 Jun 2016 20:48:33 -0400

Cc: dario.faggioli@xxxxxxxxxx, Tianyang Chen <tiche@xxxxxxxxxxxxx>, george.dunlap@xxxxxxxxxx, mengxu@xxxxxxxxxxxxx

Delivery-date: Sun, 26 Jun 2016 06:48:00 +0000

List-id: Xen developer discussion <xen-devel.lists.xen.org>

No functional change: -aligned comments in rt_vcpu struct -removed double underscores from the names of some functions -fixed coding sytle for control structures involving lists -fixed typos in the comments -added comments for UPDATE_LIMIT_SHIFT Signed-off-by: Tianyang Chen <tiche@xxxxxxxxxxxxx> --- Changes since v1: -added a detailed list of changes --- xen/common/sched_rt.c | 90 ++++++++++++++++++++++++++----------------------- 1 file changed, 48 insertions(+), 42 deletions(-) diff --git a/xen/common/sched_rt.c b/xen/common/sched_rt.c index 7f8f411..255d1f6 100644 --- a/xen/common/sched_rt.c +++ b/xen/common/sched_rt.c @@ -80,7 +80,7 @@ * in schedule.c * * The functions involes RunQ and needs to grab locks are: - * vcpu_insert, vcpu_remove, context_saved, __runq_insert + * vcpu_insert, vcpu_remove, context_saved, runq_insert */ @@ -107,6 +107,12 @@ */ #define RTDS_MIN_BUDGET (MICROSECS(10)) +/* + * UPDATE_LIMIT_SHIFT: a constant used in rt_update_deadline(). When finding + * the next deadline, performing addition could be faster if the difference + * between cur_deadline and now is small. If the difference is bigger than + * 1024 * period, use multiplication. + */ #define UPDATE_LIMIT_SHIFT 10 /* @@ -158,12 +164,12 @@ static void repl_timer_handler(void *data); /* - * Systme-wide private data, include global RunQueue/DepletedQ + * System-wide private data, include global RunQueue/DepletedQ * Global lock is referenced by schedule_data.schedule_lock from all * physical cpus. It can be grabbed via vcpu_schedule_lock_irq() */ struct rt_private { - spinlock_t lock; /* the global coarse grand lock */ + spinlock_t lock; /* the global coarse-grained lock */ struct list_head sdom; /* list of availalbe domains, used for dump */ struct list_head runq; /* ordered list of runnable vcpus */ struct list_head depletedq; /* unordered list of depleted vcpus */ @@ -176,7 +182,7 @@ struct rt_private { * Virtual CPU */ struct rt_vcpu { - struct list_head q_elem; /* on the runq/depletedq list */ + struct list_head q_elem; /* on the runq/depletedq list */ struct list_head replq_elem; /* on the replenishment events list */ /* Up-pointers */ @@ -188,11 +194,11 @@ struct rt_vcpu { s_time_t budget; /* VCPU current infomation in nanosecond */ - s_time_t cur_budget; /* current budget */ - s_time_t last_start; /* last start time */ - s_time_t cur_deadline; /* current deadline for EDF */ + s_time_t cur_budget; /* current budget */ + s_time_t last_start; /* last start time */ + s_time_t cur_deadline; /* current deadline for EDF */ - unsigned flags; /* mark __RTDS_scheduled, etc.. */ + unsigned flags; /* mark __RTDS_scheduled, etc.. */ }; /* @@ -241,13 +247,13 @@ static inline struct list_head *rt_replq(const struct scheduler *ops) * and the replenishment events queue. */ static int -__vcpu_on_q(const struct rt_vcpu *svc) +vcpu_on_q(const struct rt_vcpu *svc) { return !list_empty(&svc->q_elem); } static struct rt_vcpu * -__q_elem(struct list_head *elem) +q_elem(struct list_head *elem) { return list_entry(elem, struct rt_vcpu, q_elem); } @@ -303,7 +309,7 @@ rt_dump_vcpu(const struct scheduler *ops, const struct rt_vcpu *svc) svc->cur_budget, svc->cur_deadline, svc->last_start, - __vcpu_on_q(svc), + vcpu_on_q(svc), vcpu_runnable(svc->vcpu), svc->flags, keyhandler_scratch); @@ -339,28 +345,28 @@ rt_dump(const struct scheduler *ops) replq = rt_replq(ops); printk("Global RunQueue info:\n"); - list_for_each( iter, runq ) + list_for_each ( iter, runq ) { - svc = __q_elem(iter); + svc = q_elem(iter); rt_dump_vcpu(ops, svc); } printk("Global DepletedQueue info:\n"); - list_for_each( iter, depletedq ) + list_for_each ( iter, depletedq ) { - svc = __q_elem(iter); + svc = q_elem(iter); rt_dump_vcpu(ops, svc); } printk("Global Replenishment Events info:\n"); - list_for_each( iter, replq ) + list_for_each ( iter, replq ) { svc = replq_elem(iter); rt_dump_vcpu(ops, svc); } printk("Domain info:\n"); - list_for_each( iter, &prv->sdom ) + list_for_each ( iter, &prv->sdom ) { struct vcpu *v; @@ -380,7 +386,7 @@ rt_dump(const struct scheduler *ops) /* * update deadline and budget when now >= cur_deadline - * it need to be updated to the deadline of the current period + * it needs to be updated to the deadline of the current period */ static void rt_update_deadline(s_time_t now, struct rt_vcpu *svc) @@ -463,14 +469,14 @@ deadline_queue_insert(struct rt_vcpu * (*qelem)(struct list_head *), return !pos; } #define deadline_runq_insert(...) \ - deadline_queue_insert(&__q_elem, ##__VA_ARGS__) + deadline_queue_insert(&q_elem, ##__VA_ARGS__) #define deadline_replq_insert(...) \ deadline_queue_insert(&replq_elem, ##__VA_ARGS__) static inline void -__q_remove(struct rt_vcpu *svc) +q_remove(struct rt_vcpu *svc) { - ASSERT( __vcpu_on_q(svc) ); + ASSERT( vcpu_on_q(svc) ); list_del_init(&svc->q_elem); } @@ -506,13 +512,13 @@ replq_remove(const struct scheduler *ops, struct rt_vcpu *svc) * Insert svc without budget in DepletedQ unsorted; */ static void -__runq_insert(const struct scheduler *ops, struct rt_vcpu *svc) +runq_insert(const struct scheduler *ops, struct rt_vcpu *svc) { struct rt_private *prv = rt_priv(ops); struct list_head *runq = rt_runq(ops); ASSERT( spin_is_locked(&prv->lock) ); - ASSERT( !__vcpu_on_q(svc) ); + ASSERT( !vcpu_on_q(svc) ); ASSERT( vcpu_on_replq(svc) ); /* add svc to runq if svc still has budget */ @@ -840,12 +846,12 @@ rt_vcpu_insert(const struct scheduler *ops, struct vcpu *vc) if ( now >= svc->cur_deadline ) rt_update_deadline(now, svc); - if ( !__vcpu_on_q(svc) && vcpu_runnable(vc) ) + if ( !vcpu_on_q(svc) && vcpu_runnable(vc) ) { replq_insert(ops, svc); if ( !vc->is_running ) - __runq_insert(ops, svc); + runq_insert(ops, svc); } vcpu_schedule_unlock_irq(lock, vc); @@ -867,8 +873,8 @@ rt_vcpu_remove(const struct scheduler *ops, struct vcpu *vc) BUG_ON( sdom == NULL ); lock = vcpu_schedule_lock_irq(vc); - if ( __vcpu_on_q(svc) ) - __q_remove(svc); + if ( vcpu_on_q(svc) ) + q_remove(svc); if ( vcpu_on_replq(svc) ) replq_remove(ops,svc); @@ -955,7 +961,7 @@ burn_budget(const struct scheduler *ops, struct rt_vcpu *svc, s_time_t now) * lock is grabbed before calling this function */ static struct rt_vcpu * -__runq_pick(const struct scheduler *ops, const cpumask_t *mask) +runq_pick(const struct scheduler *ops, const cpumask_t *mask) { struct list_head *runq = rt_runq(ops); struct list_head *iter; @@ -964,9 +970,9 @@ __runq_pick(const struct scheduler *ops, const cpumask_t *mask) cpumask_t cpu_common; cpumask_t *online; - list_for_each(iter, runq) + list_for_each ( iter, runq ) { - iter_svc = __q_elem(iter); + iter_svc = q_elem(iter); /* mask cpu_hard_affinity & cpupool & mask */ online = cpupool_domain_cpumask(iter_svc->vcpu->domain); @@ -1028,7 +1034,7 @@ rt_schedule(const struct scheduler *ops, s_time_t now, bool_t tasklet_work_sched } else { - snext = __runq_pick(ops, cpumask_of(cpu)); + snext = runq_pick(ops, cpumask_of(cpu)); if ( snext == NULL ) snext = rt_vcpu(idle_vcpu[cpu]); @@ -1052,7 +1058,7 @@ rt_schedule(const struct scheduler *ops, s_time_t now, bool_t tasklet_work_sched { if ( snext != scurr ) { - __q_remove(snext); + q_remove(snext); set_bit(__RTDS_scheduled, &snext->flags); } if ( snext->vcpu->processor != cpu ) @@ -1081,9 +1087,9 @@ rt_vcpu_sleep(const struct scheduler *ops, struct vcpu *vc) if ( curr_on_cpu(vc->processor) == vc ) cpu_raise_softirq(vc->processor, SCHEDULE_SOFTIRQ); - else if ( __vcpu_on_q(svc) ) + else if ( vcpu_on_q(svc) ) { - __q_remove(svc); + q_remove(svc); replq_remove(ops, svc); } else if ( svc->flags & RTDS_delayed_runq_add ) @@ -1201,7 +1207,7 @@ rt_vcpu_wake(const struct scheduler *ops, struct vcpu *vc) } /* on RunQ/DepletedQ, just update info is ok */ - if ( unlikely(__vcpu_on_q(svc)) ) + if ( unlikely(vcpu_on_q(svc)) ) { SCHED_STAT_CRANK(vcpu_wake_onrunq); return; @@ -1245,7 +1251,7 @@ rt_vcpu_wake(const struct scheduler *ops, struct vcpu *vc) /* Replenishment event got cancelled when we blocked. Add it back. */ replq_insert(ops, svc); /* insert svc to runq/depletedq because svc is not in queue now */ - __runq_insert(ops, svc); + runq_insert(ops, svc); runq_tickle(ops, svc); } @@ -1268,7 +1274,7 @@ rt_context_saved(const struct scheduler *ops, struct vcpu *vc) if ( test_and_clear_bit(__RTDS_delayed_runq_add, &svc->flags) && likely(vcpu_runnable(vc)) ) { - __runq_insert(ops, svc); + runq_insert(ops, svc); runq_tickle(ops, svc); } else @@ -1414,10 +1420,10 @@ static void repl_timer_handler(void *data){ rt_update_deadline(now, svc); list_add(&svc->replq_elem, &tmp_replq); - if ( __vcpu_on_q(svc) ) + if ( vcpu_on_q(svc) ) { - __q_remove(svc); - __runq_insert(ops, svc); + q_remove(svc); + runq_insert(ops, svc); } } @@ -1435,12 +1441,12 @@ static void repl_timer_handler(void *data){ if ( curr_on_cpu(svc->vcpu->processor) == svc->vcpu && !list_empty(runq) ) { - struct rt_vcpu *next_on_runq = __q_elem(runq->next); + struct rt_vcpu *next_on_runq = q_elem(runq->next); if ( svc->cur_deadline > next_on_runq->cur_deadline ) runq_tickle(ops, next_on_runq); } - else if ( __vcpu_on_q(svc) && + else if ( vcpu_on_q(svc) && test_and_clear_bit(__RTDS_depleted, &svc->flags) ) runq_tickle(ops, svc); -- 1.7.9.5 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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