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authorTakashi Iwai <tiwai@suse.de>2020-08-03 14:41:43 +0200
committerTakashi Iwai <tiwai@suse.de>2020-08-03 14:41:43 +0200
commit103f528d3bc35d2b6e726a3fffd879e492d191c2 (patch)
tree2829604c2386f96e228fac7841e49906f698dfff /kernel/sched/core.c
parent07c9983b567d0ef33aefc063299de95a987e12a8 (diff)
parent84569f329f7fcb40b7b1860f273b2909dabf2a2b (diff)
Merge tag 'asoc-v5.9' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v5.9 The biggest changes here one again come from Mormioto-san who has continued his dilligent work cleaning up long standing issues in the APIs, it's particularly nice to see the transition from digital_mute() to mute_stream() finally completed. There's also been a lot of work on the x86 code again, this time a big focus has been on cleaning up some issues identified by various static tests, and on the Freescale systems. Otherwise the biggest thing has been a lot of driver additions: - Convert users of digital_mute() to mute_stream(). - Simplify I/O helper functions. - Add a helper for getting the RTD from a substream. - Many, many fixes and cleanups to the x86 code. - New drivers for Freescale MQS and i.MX6sx, Intel KeemBay I2S, Maxim MAX98360A and MAX98373 Soundwire, several Mediatek boards, nVidia Tegra 186 and 210, RealTek RL6231, Samsung Midas and Aries boards (some of the first phones I worked on!) and TI J721e EVM.
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r--kernel/sched/core.c118
1 files changed, 92 insertions, 26 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8f360326861e..2142c6767682 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1311,9 +1311,6 @@ static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
void activate_task(struct rq *rq, struct task_struct *p, int flags)
{
- if (task_contributes_to_load(p))
- rq->nr_uninterruptible--;
-
enqueue_task(rq, p, flags);
p->on_rq = TASK_ON_RQ_QUEUED;
@@ -1323,9 +1320,6 @@ void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
{
p->on_rq = (flags & DEQUEUE_SLEEP) ? 0 : TASK_ON_RQ_MIGRATING;
- if (task_contributes_to_load(p))
- rq->nr_uninterruptible++;
-
dequeue_task(rq, p, flags);
}
@@ -1637,7 +1631,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
goto out;
}
- if (cpumask_equal(p->cpus_ptr, new_mask))
+ if (cpumask_equal(&p->cpus_mask, new_mask))
goto out;
/*
@@ -2236,10 +2230,10 @@ ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags,
lockdep_assert_held(&rq->lock);
-#ifdef CONFIG_SMP
if (p->sched_contributes_to_load)
rq->nr_uninterruptible--;
+#ifdef CONFIG_SMP
if (wake_flags & WF_MIGRATED)
en_flags |= ENQUEUE_MIGRATED;
#endif
@@ -2293,8 +2287,15 @@ void sched_ttwu_pending(void *arg)
rq_lock_irqsave(rq, &rf);
update_rq_clock(rq);
- llist_for_each_entry_safe(p, t, llist, wake_entry)
+ llist_for_each_entry_safe(p, t, llist, wake_entry.llist) {
+ if (WARN_ON_ONCE(p->on_cpu))
+ smp_cond_load_acquire(&p->on_cpu, !VAL);
+
+ if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq)))
+ set_task_cpu(p, cpu_of(rq));
+
ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0, &rf);
+ }
rq_unlock_irqrestore(rq, &rf);
}
@@ -2322,7 +2323,7 @@ static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags
p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED);
WRITE_ONCE(rq->ttwu_pending, 1);
- __smp_call_single_queue(cpu, &p->wake_entry);
+ __smp_call_single_queue(cpu, &p->wake_entry.llist);
}
void wake_up_if_idle(int cpu)
@@ -2369,7 +2370,7 @@ static inline bool ttwu_queue_cond(int cpu, int wake_flags)
* the soon-to-be-idle CPU as the current CPU is likely busy.
* nr_running is checked to avoid unnecessary task stacking.
*/
- if ((wake_flags & WF_ON_RQ) && cpu_rq(cpu)->nr_running <= 1)
+ if ((wake_flags & WF_ON_CPU) && cpu_rq(cpu)->nr_running <= 1)
return true;
return false;
@@ -2378,6 +2379,9 @@ static inline bool ttwu_queue_cond(int cpu, int wake_flags)
static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags)
{
if (sched_feat(TTWU_QUEUE) && ttwu_queue_cond(cpu, wake_flags)) {
+ if (WARN_ON_ONCE(cpu == smp_processor_id()))
+ return false;
+
sched_clock_cpu(cpu); /* Sync clocks across CPUs */
__ttwu_queue_wakelist(p, cpu, wake_flags);
return true;
@@ -2528,7 +2532,6 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
goto out;
success = 1;
- cpu = task_cpu(p);
trace_sched_waking(p);
p->state = TASK_RUNNING;
trace_sched_wakeup(p);
@@ -2550,7 +2553,6 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
/* We're going to change ->state: */
success = 1;
- cpu = task_cpu(p);
/*
* Ensure we load p->on_rq _after_ p->state, otherwise it would
@@ -2575,7 +2577,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
* A similar smb_rmb() lives in try_invoke_on_locked_down_task().
*/
smp_rmb();
- if (p->on_rq && ttwu_remote(p, wake_flags))
+ if (READ_ONCE(p->on_rq) && ttwu_remote(p, wake_flags))
goto unlock;
if (p->in_iowait) {
@@ -2584,9 +2586,6 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
}
#ifdef CONFIG_SMP
- p->sched_contributes_to_load = !!task_contributes_to_load(p);
- p->state = TASK_WAKING;
-
/*
* Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be
* possible to, falsely, observe p->on_cpu == 0.
@@ -2605,8 +2604,20 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
*
* Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in
* __schedule(). See the comment for smp_mb__after_spinlock().
+ *
+ * Form a control-dep-acquire with p->on_rq == 0 above, to ensure
+ * schedule()'s deactivate_task() has 'happened' and p will no longer
+ * care about it's own p->state. See the comment in __schedule().
*/
- smp_rmb();
+ smp_acquire__after_ctrl_dep();
+
+ /*
+ * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq
+ * == 0), which means we need to do an enqueue, change p->state to
+ * TASK_WAKING such that we can unlock p->pi_lock before doing the
+ * enqueue, such as ttwu_queue_wakelist().
+ */
+ p->state = TASK_WAKING;
/*
* If the owning (remote) CPU is still in the middle of schedule() with
@@ -2614,8 +2625,21 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
* which potentially sends an IPI instead of spinning on p->on_cpu to
* let the waker make forward progress. This is safe because IRQs are
* disabled and the IPI will deliver after on_cpu is cleared.
+ *
+ * Ensure we load task_cpu(p) after p->on_cpu:
+ *
+ * set_task_cpu(p, cpu);
+ * STORE p->cpu = @cpu
+ * __schedule() (switch to task 'p')
+ * LOCK rq->lock
+ * smp_mb__after_spin_lock() smp_cond_load_acquire(&p->on_cpu)
+ * STORE p->on_cpu = 1 LOAD p->cpu
+ *
+ * to ensure we observe the correct CPU on which the task is currently
+ * scheduling.
*/
- if (READ_ONCE(p->on_cpu) && ttwu_queue_wakelist(p, cpu, wake_flags | WF_ON_RQ))
+ if (smp_load_acquire(&p->on_cpu) &&
+ ttwu_queue_wakelist(p, task_cpu(p), wake_flags | WF_ON_CPU))
goto unlock;
/*
@@ -2635,6 +2659,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
psi_ttwu_dequeue(p);
set_task_cpu(p, cpu);
}
+#else
+ cpu = task_cpu(p);
#endif /* CONFIG_SMP */
ttwu_queue(p, cpu, wake_flags);
@@ -2642,7 +2668,7 @@ unlock:
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
out:
if (success)
- ttwu_stat(p, cpu, wake_flags);
+ ttwu_stat(p, task_cpu(p), wake_flags);
preempt_enable();
return success;
@@ -2763,7 +2789,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
#endif
init_numa_balancing(clone_flags, p);
#ifdef CONFIG_SMP
- p->wake_entry_type = CSD_TYPE_TTWU;
+ p->wake_entry.u_flags = CSD_TYPE_TTWU;
#endif
}
@@ -2939,6 +2965,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
* Silence PROVE_RCU.
*/
raw_spin_lock_irqsave(&p->pi_lock, flags);
+ rseq_migrate(p);
/*
* We're setting the CPU for the first time, we don't migrate,
* so use __set_task_cpu().
@@ -3003,6 +3030,7 @@ void wake_up_new_task(struct task_struct *p)
* as we're not fully set-up yet.
*/
p->recent_used_cpu = task_cpu(p);
+ rseq_migrate(p);
__set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0));
#endif
rq = __task_rq_lock(p, &rf);
@@ -4074,6 +4102,7 @@ static void __sched notrace __schedule(bool preempt)
{
struct task_struct *prev, *next;
unsigned long *switch_count;
+ unsigned long prev_state;
struct rq_flags rf;
struct rq *rq;
int cpu;
@@ -4093,9 +4122,16 @@ static void __sched notrace __schedule(bool preempt)
/*
* Make sure that signal_pending_state()->signal_pending() below
* can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
- * done by the caller to avoid the race with signal_wake_up().
+ * done by the caller to avoid the race with signal_wake_up():
*
- * The membarrier system call requires a full memory barrier
+ * __set_current_state(@state) signal_wake_up()
+ * schedule() set_tsk_thread_flag(p, TIF_SIGPENDING)
+ * wake_up_state(p, state)
+ * LOCK rq->lock LOCK p->pi_state
+ * smp_mb__after_spinlock() smp_mb__after_spinlock()
+ * if (signal_pending_state()) if (p->state & @state)
+ *
+ * Also, the membarrier system call requires a full memory barrier
* after coming from user-space, before storing to rq->curr.
*/
rq_lock(rq, &rf);
@@ -4106,10 +4142,38 @@ static void __sched notrace __schedule(bool preempt)
update_rq_clock(rq);
switch_count = &prev->nivcsw;
- if (!preempt && prev->state) {
- if (signal_pending_state(prev->state, prev)) {
+
+ /*
+ * We must load prev->state once (task_struct::state is volatile), such
+ * that:
+ *
+ * - we form a control dependency vs deactivate_task() below.
+ * - ptrace_{,un}freeze_traced() can change ->state underneath us.
+ */
+ prev_state = prev->state;
+ if (!preempt && prev_state) {
+ if (signal_pending_state(prev_state, prev)) {
prev->state = TASK_RUNNING;
} else {
+ prev->sched_contributes_to_load =
+ (prev_state & TASK_UNINTERRUPTIBLE) &&
+ !(prev_state & TASK_NOLOAD) &&
+ !(prev->flags & PF_FROZEN);
+
+ if (prev->sched_contributes_to_load)
+ rq->nr_uninterruptible++;
+
+ /*
+ * __schedule() ttwu()
+ * prev_state = prev->state; if (p->on_rq && ...)
+ * if (prev_state) goto out;
+ * p->on_rq = 0; smp_acquire__after_ctrl_dep();
+ * p->state = TASK_WAKING
+ *
+ * Where __schedule() and ttwu() have matching control dependencies.
+ *
+ * After this, schedule() must not care about p->state any more.
+ */
deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK);
if (prev->in_iowait) {
@@ -4421,6 +4485,7 @@ asmlinkage __visible void __sched preempt_schedule_irq(void)
int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags,
void *key)
{
+ WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~WF_SYNC);
return try_to_wake_up(curr->private, mode, wake_flags);
}
EXPORT_SYMBOL(default_wake_function);
@@ -4533,7 +4598,8 @@ 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))) {
+ (pi_task && dl_prio(pi_task->prio) &&
+ dl_entity_preempt(&pi_task->dl, &p->dl))) {
p->dl.dl_boosted = 1;
queue_flag |= ENQUEUE_REPLENISH;
} else