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sched/fair: Use reweight_entity() for set_user_nice()

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Now that we directly change load_avg and propagate that change into
the sums, sys_nice() and co should do the same, otherwise its possible
to confuse load accounting when we migrate near the weight change.

Fixes-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
[ Added changelog, fixed the call condition. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20170517095045.GA8420@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Vincent Guittot 2017-05-17 11:50:45 +02:00 committed by Ingo Molnar
parent 840c5abca4
commit 9059393e4e
3 changed files with 54 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
kernel/sched/core.c
View File

@ -733,7 +733,7 @@ int tg_nop(struct task_group *tg, void *data)
}
#endif
static void set_load_weight(struct task_struct *p)
static void set_load_weight(struct task_struct *p, bool update_load)
{
int prio = p->static_prio - MAX_RT_PRIO;
struct load_weight *load = &p->se.load;
@ -747,8 +747,16 @@ static void set_load_weight(struct task_struct *p)
return;
}
load->weight = scale_load(sched_prio_to_weight[prio]);
load->inv_weight = sched_prio_to_wmult[prio];
/*
* SCHED_OTHER tasks have to update their load when changing their
* weight
*/
if (update_load && p->sched_class == &fair_sched_class) {
reweight_task(p, prio);
} else {
load->weight = scale_load(sched_prio_to_weight[prio]);
load->inv_weight = sched_prio_to_wmult[prio];
}
}
static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
@ -2358,7 +2366,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
p->static_prio = NICE_TO_PRIO(0);
p->prio = p->normal_prio = __normal_prio(p);
set_load_weight(p);
set_load_weight(p, false);
/*
* We don't need the reset flag anymore after the fork. It has
@ -3805,7 +3813,7 @@ void set_user_nice(struct task_struct *p, long nice)
put_prev_task(rq, p);
p->static_prio = NICE_TO_PRIO(nice);
set_load_weight(p);
set_load_weight(p, true);
old_prio = p->prio;
p->prio = effective_prio(p);
delta = p->prio - old_prio;
@ -3962,7 +3970,7 @@ static void __setscheduler_params(struct task_struct *p,
*/
p->rt_priority = attr->sched_priority;
p->normal_prio = normal_prio(p);
set_load_weight(p);
set_load_weight(p, true);
}
/* Actually do priority change: must hold pi & rq lock. */
@ -5933,7 +5941,7 @@ void __init sched_init(void)
atomic_set(&rq->nr_iowait, 0);
}
set_load_weight(&init_task);
set_load_weight(&init_task, false);
/*
* The boot idle thread does lazy MMU switching as well:

63
kernel/sched/fair.c
View File

@ -2776,6 +2776,43 @@ static inline void
dequeue_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { }
#endif
static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
unsigned long weight)
{
if (se->on_rq) {
/* commit outstanding execution time */
if (cfs_rq->curr == se)
update_curr(cfs_rq);
account_entity_dequeue(cfs_rq, se);
dequeue_runnable_load_avg(cfs_rq, se);
}
dequeue_load_avg(cfs_rq, se);
update_load_set(&se->load, weight);
#ifdef CONFIG_SMP
se->avg.load_avg = div_u64(se_weight(se) * se->avg.load_sum,
LOAD_AVG_MAX - 1024 + se->avg.period_contrib);
#endif
enqueue_load_avg(cfs_rq, se);
if (se->on_rq) {
account_entity_enqueue(cfs_rq, se);
enqueue_runnable_load_avg(cfs_rq, se);
}
}
void reweight_task(struct task_struct *p, int prio)
{
struct sched_entity *se = &p->se;
struct cfs_rq *cfs_rq = cfs_rq_of(se);
struct load_weight *load = &se->load;
unsigned long weight = scale_load(sched_prio_to_weight[prio]);
reweight_entity(cfs_rq, se, weight);
load->inv_weight = sched_prio_to_wmult[prio];
}
#ifdef CONFIG_FAIR_GROUP_SCHED
# ifdef CONFIG_SMP
/*
@ -2878,32 +2915,6 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq)
}
# endif /* CONFIG_SMP */
static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
unsigned long weight)
{
if (se->on_rq) {
/* commit outstanding execution time */
if (cfs_rq->curr == se)
update_curr(cfs_rq);
account_entity_dequeue(cfs_rq, se);
dequeue_runnable_load_avg(cfs_rq, se);
}
dequeue_load_avg(cfs_rq, se);
update_load_set(&se->load, weight);
#ifdef CONFIG_SMP
se->avg.load_avg = div_u64(se_weight(se) * se->avg.load_sum,
LOAD_AVG_MAX - 1024 + se->avg.period_contrib);
#endif
enqueue_load_avg(cfs_rq, se);
if (se->on_rq) {
account_entity_enqueue(cfs_rq, se);
enqueue_runnable_load_avg(cfs_rq, se);
}
}
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
static void update_cfs_shares(struct sched_entity *se)

2
kernel/sched/sched.h
View File

@ -1529,6 +1529,8 @@ extern void init_sched_dl_class(void);
extern void init_sched_rt_class(void);
extern void init_sched_fair_class(void);
extern void reweight_task(struct task_struct *p, int prio);
extern void resched_curr(struct rq *rq);
extern void resched_cpu(int cpu);