From: Andres Rodriguez <andres.rodriguez@amd.com>
Date: Fri, 27 Oct 2017 19:35:34 -0400
Subject: drm/amdkfd: use a high priority workqueue for IH work
Git-commit: 48e876a20e79566f1736413d4f42dc66f3ab2f16
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
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>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_device.c | 2 +-
drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c | 3 ++-
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 1 +
3 files changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
@@ -403,7 +403,7 @@ void kgd2kfd_interrupt(struct kfd_dev *k
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);
}
--- a/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c
@@ -61,6 +61,7 @@ int kfd_interrupt_init(struct kfd_dev *k
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 *
* 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);
}
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -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;