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authorDaniel Vetter <daniel.vetter@ffwll.ch>2015-12-11 19:28:27 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-12-11 19:28:27 +0100
commit618100f8a84b8a97f7c1a0e03acf0d466102f40f (patch)
treeac2d163c55da7c9704402581553cad68e3671a51 /kernel/sched/core.c
parent9e7d18c08a4ec3b76b6a0994e93258decb250fbe (diff)
parent0bdf5a05647a66dcc6394986e061daeac9b1cf96 (diff)
Merge tag 'drm-i915-get-eld' of tiwai/sound into drm-intel-next-queued
Add get_eld audio component for i915/HD-audio Currently, the HDMI/DP audio status and ELD are notified and obtained via the hardware-level communication over HD-audio unsolicited event and verbs although the graphics driver holds the exactly same information. As we already have a notification via audio component, this is another step forward; namely, the audio driver may fetch directly the audio status and ELD via the new component op. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r--kernel/sched/core.c36
1 files changed, 30 insertions, 6 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4d568ac9319e..7063c6a07440 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1947,13 +1947,38 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
#ifdef CONFIG_SMP
/*
+ * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be
+ * possible to, falsely, observe p->on_cpu == 0.
+ *
+ * One must be running (->on_cpu == 1) in order to remove oneself
+ * from the runqueue.
+ *
+ * [S] ->on_cpu = 1; [L] ->on_rq
+ * UNLOCK rq->lock
+ * RMB
+ * LOCK rq->lock
+ * [S] ->on_rq = 0; [L] ->on_cpu
+ *
+ * Pairs with the full barrier implied in the UNLOCK+LOCK on rq->lock
+ * from the consecutive calls to schedule(); the first switching to our
+ * task, the second putting it to sleep.
+ */
+ smp_rmb();
+
+ /*
* If the owning (remote) cpu is still in the middle of schedule() with
* this task as prev, wait until its done referencing the task.
*/
while (p->on_cpu)
cpu_relax();
/*
- * Pairs with the smp_wmb() in finish_lock_switch().
+ * Combined with the control dependency above, we have an effective
+ * smp_load_acquire() without the need for full barriers.
+ *
+ * Pairs with the smp_store_release() in finish_lock_switch().
+ *
+ * This ensures that tasks getting woken will be fully ordered against
+ * their previous state and preserve Program Order.
*/
smp_rmb();
@@ -2039,7 +2064,6 @@ out:
*/
int wake_up_process(struct task_struct *p)
{
- WARN_ON(task_is_stopped_or_traced(p));
return try_to_wake_up(p, TASK_NORMAL, 0);
}
EXPORT_SYMBOL(wake_up_process);
@@ -5847,13 +5871,13 @@ static int init_rootdomain(struct root_domain *rd)
{
memset(rd, 0, sizeof(*rd));
- if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&rd->span, GFP_KERNEL))
goto out;
- if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&rd->online, GFP_KERNEL))
goto free_span;
- if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL))
goto free_online;
- if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
goto free_dlo_mask;
init_dl_bw(&rd->dl_bw);