drm/amdkfd: use a high priority workqueue for IH work

In systems under heavy load the IH work may experience significant
scheduling delays.

Under load + system workqueue:
    Max Latency: 7.023695 ms
    Avg Latency: 0.263994 ms

Under load + high priority workqueue:
    Max Latency: 1.162568 ms
    Avg Latency: 0.163213 ms

Further work is required to measure the impact of per-cpu settings on IH
performance.

Signed-off-by: Andres Rodriguez <andres.rodriguez@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Acked-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
This commit is contained in:
Andres Rodriguez 2017-10-27 19:35:34 -04:00 committed by Oded Gabbay
parent 0f875e3f3e
commit 48e876a20e
3 changed files with 4 additions and 2 deletions

View File

@ -403,7 +403,7 @@ void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry)
if (kfd->interrupts_active
&& interrupt_is_wanted(kfd, ih_ring_entry)
&& enqueue_ih_ring_entry(kfd, ih_ring_entry))
schedule_work(&kfd->interrupt_work);
queue_work(kfd->ih_wq, &kfd->interrupt_work);
spin_unlock(&kfd->interrupt_lock);
}

View File

@ -61,6 +61,7 @@ int kfd_interrupt_init(struct kfd_dev *kfd)
return r;
}
kfd->ih_wq = alloc_workqueue("KFD IH", WQ_HIGHPRI, 1);
spin_lock_init(&kfd->interrupt_lock);
INIT_WORK(&kfd->interrupt_work, interrupt_wq);
@ -95,7 +96,7 @@ void kfd_interrupt_exit(struct kfd_dev *kfd)
* work-queue items that will access interrupt_ring. New work items
* can't be created because we stopped interrupt handling above.
*/
flush_work(&kfd->interrupt_work);
flush_workqueue(kfd->ih_wq);
kfifo_free(&kfd->ih_fifo);
}

View File

@ -184,6 +184,7 @@ struct kfd_dev {
/* Interrupts */
struct kfifo ih_fifo;
struct workqueue_struct *ih_wq;
struct work_struct interrupt_work;
spinlock_t interrupt_lock;