Messages in this thread Patch in this message | | | Date | Tue, 21 Nov 2017 11:44:05 +0100 (CET) | From | Jiri Kosina <> | Subject | [PATCH] sched/deadline: Use bools for the state flags |
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From: Jiri Kosina <jkosina@suse.cz>
Commit
799ba82de01e ("sched/deadline: Use C bitfields for the state flags")
converted state flags into one-bit signed int. Signed one-bit type can be either 0 or -1, which is going to cause a problem once 1 is assigned to it and then the value later tested against 1.
The current code is okay, as all the checks are (non-)zero check, but I believe that we'd rather be safe than sorry here; remove the fragility by converting the state flags to bool.
This also silences annoying sparse complaints about this very issue when compiling any code that includes sched.h.
Fixes: 799ba82de01e ("sched/deadline: Use C bitfields for the state flags") Cc: luca abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz> --- include/linux/sched.h | 8 ++++---- kernel/sched/core.c | 8 ++++---- kernel/sched/deadline.c | 32 ++++++++++++++++---------------- 3 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h index a5dc7c98b0a2..b19fa1b96726 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -473,10 +473,10 @@ struct sched_dl_entity { * conditions between the inactive timer handler and the wakeup * code. */ - int dl_throttled : 1; - int dl_boosted : 1; - int dl_yielded : 1; - int dl_non_contending : 1; + bool dl_throttled; + bool dl_boosted; + bool dl_yielded; + bool dl_non_contending; /* * Bandwidth enforcement timer. Each -deadline task has its diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 75554f366fd3..f9bbf0f55e0e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3738,20 +3738,20 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) if (dl_prio(prio)) { if (!dl_prio(p->normal_prio) || (pi_task && dl_entity_preempt(&pi_task->dl, &p->dl))) { - p->dl.dl_boosted = 1; + p->dl.dl_boosted = true; queue_flag |= ENQUEUE_REPLENISH; } else - p->dl.dl_boosted = 0; + p->dl.dl_boosted = false; p->sched_class = &dl_sched_class; } else if (rt_prio(prio)) { if (dl_prio(oldprio)) - p->dl.dl_boosted = 0; + p->dl.dl_boosted = false; if (oldprio < prio) queue_flag |= ENQUEUE_HEAD; p->sched_class = &rt_sched_class; } else { if (dl_prio(oldprio)) - p->dl.dl_boosted = 0; + p->dl.dl_boosted = false; if (rt_prio(oldprio)) p->rt.timeout = 0; p->sched_class = &fair_sched_class; diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 2473736c7616..78cb00ae8b2f 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -133,7 +133,7 @@ void dl_change_utilization(struct task_struct *p, u64 new_bw) rq = task_rq(p); if (p->dl.dl_non_contending) { sub_running_bw(p->dl.dl_bw, &rq->dl); - p->dl.dl_non_contending = 0; + p->dl.dl_non_contending = false; /* * If the timer handler is currently running and the * timer cannot be cancelled, inactive_task_timer() @@ -251,7 +251,7 @@ static void task_non_contending(struct task_struct *p) return; } - dl_se->dl_non_contending = 1; + dl_se->dl_non_contending = true; get_task_struct(p); hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL); } @@ -271,7 +271,7 @@ static void task_contending(struct sched_dl_entity *dl_se, int flags) add_rq_bw(dl_se->dl_bw, dl_rq); if (dl_se->dl_non_contending) { - dl_se->dl_non_contending = 0; + dl_se->dl_non_contending = false; /* * If the timer handler is currently running and the * timer cannot be cancelled, inactive_task_timer() @@ -676,9 +676,9 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se, } if (dl_se->dl_yielded) - dl_se->dl_yielded = 0; + dl_se->dl_yielded = false; if (dl_se->dl_throttled) - dl_se->dl_throttled = 0; + dl_se->dl_throttled = false; } /* @@ -1051,7 +1051,7 @@ static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se) dl_time_before(rq_clock(rq), dl_next_period(dl_se))) { if (unlikely(dl_se->dl_boosted || !start_dl_timer(p))) return; - dl_se->dl_throttled = 1; + dl_se->dl_throttled = true; if (dl_se->runtime > 0) dl_se->runtime = 0; } @@ -1154,7 +1154,7 @@ static void update_curr_dl(struct rq *rq) throttle: if (dl_runtime_exceeded(dl_se) || dl_se->dl_yielded) { - dl_se->dl_throttled = 1; + dl_se->dl_throttled = true; __dequeue_task_dl(rq, curr, 0); if (unlikely(dl_se->dl_boosted || !start_dl_timer(curr))) enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH); @@ -1206,7 +1206,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) if (p->state == TASK_DEAD && dl_se->dl_non_contending) { sub_running_bw(p->dl.dl_bw, dl_rq_of_se(&p->dl)); sub_rq_bw(p->dl.dl_bw, dl_rq_of_se(&p->dl)); - dl_se->dl_non_contending = 0; + dl_se->dl_non_contending = false; } raw_spin_lock(&dl_b->lock); @@ -1216,14 +1216,14 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) goto unlock; } - if (dl_se->dl_non_contending == 0) + if (!dl_se->dl_non_contending) goto unlock; sched_clock_tick(); update_rq_clock(rq); sub_running_bw(dl_se->dl_bw, &rq->dl); - dl_se->dl_non_contending = 0; + dl_se->dl_non_contending = false; unlock: task_rq_unlock(rq, p, &rf); put_task_struct(p); @@ -1492,7 +1492,7 @@ static void yield_task_dl(struct rq *rq) * it and the bandwidth timer will wake it up and will give it * new scheduling parameters (thanks to dl_yielded=1). */ - rq->curr->dl.dl_yielded = 1; + rq->curr->dl.dl_yielded = true; update_rq_clock(rq); update_curr_dl(rq); @@ -1565,7 +1565,7 @@ static void migrate_task_rq_dl(struct task_struct *p) raw_spin_lock(&rq->lock); if (p->dl.dl_non_contending) { sub_running_bw(p->dl.dl_bw, &rq->dl); - p->dl.dl_non_contending = 0; + p->dl.dl_non_contending = false; /* * If the timer handler is currently running and the * timer cannot be cancelled, inactive_task_timer() @@ -2232,7 +2232,7 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) * while SCHED_OTHER in the meanwhile. */ if (p->dl.dl_non_contending) - p->dl.dl_non_contending = 0; + p->dl.dl_non_contending = false; /* * Since this might be the only -deadline task on the rq, @@ -2563,9 +2563,9 @@ void __dl_clear_params(struct task_struct *p) dl_se->dl_bw = 0; dl_se->dl_density = 0; - dl_se->dl_throttled = 0; - dl_se->dl_yielded = 0; - dl_se->dl_non_contending = 0; + dl_se->dl_throttled = false; + dl_se->dl_yielded = false; + dl_se->dl_non_contending = false; } bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr) -- Jiri Kosina SUSE Labs
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