Commit 34db5a32 authored by Philip Yang's avatar Philip Yang Committed by Alex Deucher
Browse files

drm/amdkfd: Queue interrupt work to different CPU 



For CPX mode, each KFD node has interrupt worker to process ih_fifo to
send events to user space. Currently all interrupt workers of same adev
queue to same CPU, all workers execution are actually serialized and
this cause KFD ih_fifo overflow when CPU usage is high.

Use per-GPU unbounded highpri queue with number of workers equals to
number of partitions, let queue_work select the next CPU round robin
among the local CPUs of same NUMA.

Signed-off-by: default avatarPhilip Yang <Philip.Yang@amd.com>
Reviewed-by: default avatarFelix Kuehling <felix.kuehling@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 1b001432

drivers/gpu/drm/amd/amdkfd/kfd_device.c

+9 −16
Original line number Diff line number Diff line
@@ -649,6 +649,14 @@ static void kfd_cleanup_nodes(struct kfd_dev *kfd, unsigned int num_nodes) 
	struct kfd_node *knode;

	unsigned int i;



	/*

	 * flush_work ensures that there are no outstanding

	 * work-queue items that will access interrupt_ring. New work items

	 * can't be created because we stopped interrupt handling above.

	 */

	flush_workqueue(kfd->ih_wq);

	destroy_workqueue(kfd->ih_wq);



	for (i = 0; i < num_nodes; i++) {

		knode = kfd->nodes[i];

		device_queue_manager_uninit(knode->dqm);
@@ -1066,21 +1074,6 @@ static int kfd_resume(struct kfd_node *node) 
	return err;

}



static inline void kfd_queue_work(struct workqueue_struct *wq,

				  struct work_struct *work)

{

	int cpu, new_cpu;



	cpu = new_cpu = smp_processor_id();

	do {

		new_cpu = cpumask_next(new_cpu, cpu_online_mask) % nr_cpu_ids;

		if (cpu_to_node(new_cpu) == numa_node_id())

			break;

	} while (cpu != new_cpu);



	queue_work_on(new_cpu, wq, work);

}



/* This is called directly from KGD at ISR. */

void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry)

{
@@ -1106,7 +1099,7 @@ void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry) 
			    	patched_ihre, &is_patched)

		    && enqueue_ih_ring_entry(node,

			    	is_patched ? patched_ihre : ih_ring_entry)) {

			kfd_queue_work(node->ih_wq, &node->interrupt_work);

			queue_work(node->kfd->ih_wq, &node->interrupt_work);

			spin_unlock_irqrestore(&node->interrupt_lock, flags);

			return;

		}

drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c

+9 −16
Original line number Diff line number Diff line
@@ -62,12 +62,15 @@ int kfd_interrupt_init(struct kfd_node *node) 
		return r;

	}



	node->ih_wq = alloc_workqueue("KFD IH", WQ_HIGHPRI, 1);

	if (unlikely(!node->ih_wq)) {

	if (!node->kfd->ih_wq) {

		node->kfd->ih_wq = alloc_workqueue("KFD IH", WQ_HIGHPRI | WQ_UNBOUND,

						   node->kfd->num_nodes);

		if (unlikely(!node->kfd->ih_wq)) {

			kfifo_free(&node->ih_fifo);

			dev_err(node->adev->dev, "Failed to allocate KFD IH workqueue\n");

			return -ENOMEM;

		}

	}

	spin_lock_init(&node->interrupt_lock);



	INIT_WORK(&node->interrupt_work, interrupt_wq);
@@ -96,16 +99,6 @@ void kfd_interrupt_exit(struct kfd_node *node) 
	spin_lock_irqsave(&node->interrupt_lock, flags);

	node->interrupts_active = false;

	spin_unlock_irqrestore(&node->interrupt_lock, flags);



	/*

	 * flush_work ensures that there are no outstanding

	 * work-queue items that will access interrupt_ring. New work items

	 * can't be created because we stopped interrupt handling above.

	 */

	flush_workqueue(node->ih_wq);



	destroy_workqueue(node->ih_wq);



	kfifo_free(&node->ih_fifo);

}
@@ -155,7 +148,7 @@ static void interrupt_wq(struct work_struct *work) 
			/* If we spent more than a second processing signals,

			 * reschedule the worker to avoid soft-lockup warnings

			 */

			queue_work(dev->ih_wq, &dev->interrupt_work);

			queue_work(dev->kfd->ih_wq, &dev->interrupt_work);

			break;

		}

	}

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

+2 −1
Original line number Diff line number Diff line
@@ -274,7 +274,6 @@ struct kfd_node { 


	/* Interrupts */

	struct kfifo ih_fifo;

	struct workqueue_struct *ih_wq;

	struct work_struct interrupt_work;

	spinlock_t interrupt_lock;
@@ -367,6 +366,8 @@ struct kfd_dev { 
	struct kfd_node *nodes[MAX_KFD_NODES];

	unsigned int num_nodes;



	struct workqueue_struct *ih_wq;



	/* Kernel doorbells for KFD device */

	struct amdgpu_bo *doorbells;