Use an LRU policy to map usermode rings to HW compute queues.

Most compute clients use one queue, and usually the first queue
available. This results in poor pipe/queue work distribution when
multiple compute apps are running. In most cases pipe 0 queue 0 is
the only queue that gets used.

In order to better distribute work across multiple HW queues, we adopt
a policy to map the usermode ring ids to the LRU HW queue.

This fixes a large majority of multi-app compute workloads sharing the
same HW queue, even though 7 other queues are available.

v2: use ring->funcs->type instead of ring->hw_ip

Signed-off-by: Andres Rodriguez <andre...@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h           |  3 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |  3 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_queue_mgr.c | 52 +++++++++++++++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c      | 57 +++++++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h      |  4 ++
 5 files changed, 117 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index dc79c0e..a4c16a8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1517,6 +1517,9 @@ struct amdgpu_device {
        /* link all gtt */
        spinlock_t                      gtt_list_lock;
        struct list_head                gtt_list;
+       /* keep an lru list of rings by HW IP */
+       struct list_head                ring_lru_list;
+       struct mutex                    ring_lru_list_lock;
 
        /* record hw reset is performed */
        bool has_hw_reset;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 6abb238..954e3b9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -1719,6 +1719,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
        INIT_LIST_HEAD(&adev->gtt_list);
        spin_lock_init(&adev->gtt_list_lock);
 
+       INIT_LIST_HEAD(&adev->ring_lru_list);
+       mutex_init(&adev->ring_lru_list_lock);
+
        if (adev->asic_type >= CHIP_BONAIRE) {
                adev->rmmio_base = pci_resource_start(adev->pdev, 5);
                adev->rmmio_size = pci_resource_len(adev->pdev, 5);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_queue_mgr.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_queue_mgr.c
index 3918bdb..0cf5d24 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_queue_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_queue_mgr.c
@@ -97,6 +97,44 @@ static struct amdgpu_queue_mapper_funcs identity_mapper = {
        .map = amdgpu_identity_map
 };
 
+static enum amdgpu_ring_type amdgpu_hw_ip_to_ring_type(int hw_ip)
+{
+       switch (hw_ip) {
+       case AMDGPU_HW_IP_GFX:
+               return AMDGPU_RING_TYPE_GFX;
+       case AMDGPU_HW_IP_COMPUTE:
+               return AMDGPU_RING_TYPE_COMPUTE;
+       case AMDGPU_HW_IP_DMA:
+               return AMDGPU_RING_TYPE_SDMA;
+       case AMDGPU_HW_IP_UVD:
+               return AMDGPU_RING_TYPE_UVD;
+       case AMDGPU_HW_IP_VCE:
+               return AMDGPU_RING_TYPE_VCE;
+       default:
+               DRM_ERROR("Invalid HW IP specified %d\n", hw_ip);
+               return -1;
+       }
+}
+
+static int amdgpu_lru_map(struct amdgpu_device *adev,
+                         struct amdgpu_queue_mapper *mapper,
+                         int user_ring,
+                         struct amdgpu_ring **out_ring)
+{
+       int r;
+       int ring_type = amdgpu_hw_ip_to_ring_type(mapper->hw_ip);
+
+       r = amdgpu_ring_lru_get(adev, ring_type, out_ring);
+       if (r)
+               return r;
+
+       return update_cached_map(mapper, user_ring, *out_ring);
+}
+
+static struct amdgpu_queue_mapper_funcs lru_mapper = {
+       .map = amdgpu_lru_map
+};
+
 int amdgpu_queue_mgr_init(struct amdgpu_device *adev,
                          struct amdgpu_queue_mgr *mgr)
 {
@@ -107,8 +145,18 @@ int amdgpu_queue_mgr_init(struct amdgpu_device *adev,
 
        memset(mgr, 0, sizeof(*mgr));
 
-       for (i = 0; i < AMDGPU_MAX_IP_NUM; ++i)
-               amdgpu_queue_mapper_init(&mgr->mapper[i], i, &identity_mapper);
+       for (i = 0; i < AMDGPU_MAX_IP_NUM; ++i) {
+               switch (i) {
+               case AMDGPU_HW_IP_COMPUTE:
+                       amdgpu_queue_mapper_init(&mgr->mapper[i], i,
+                                                &lru_mapper);
+                       break;
+               default:
+                       amdgpu_queue_mapper_init(&mgr->mapper[i], i,
+                                                &identity_mapper);
+                       break;
+               }
+       }
 
        return 0;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 43cd539..31c6274 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -180,6 +180,8 @@ void amdgpu_ring_commit(struct amdgpu_ring *ring)
 
        if (ring->funcs->end_use)
                ring->funcs->end_use(ring);
+
+       amdgpu_ring_lru_touch(ring->adev, ring);
 }
 
 /**
@@ -279,6 +281,8 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct 
amdgpu_ring *ring,
        }
        ring->ptr_mask = (ring->ring_size / 4) - 1;
        ring->max_dw = max_dw;
+       INIT_LIST_HEAD(&ring->lru_list);
+       amdgpu_ring_lru_touch(adev, ring);
 
        if (amdgpu_debugfs_ring_init(adev, ring)) {
                DRM_ERROR("Failed to register debugfs file for rings !\n");
@@ -312,6 +316,59 @@ void amdgpu_ring_fini(struct amdgpu_ring *ring)
        ring->adev->rings[ring->idx] = NULL;
 }
 
+/**
+ * amdgpu_ring_lru_get - get the least recently used ring for a HW IP block
+ *
+ * @adev: amdgpu_device pointer
+ * @type: amdgpu_ring_type enum
+ * @ring: output ring
+ *
+ * Retreive the amdgpu_ring structure for the least recently used ring of
+ * a specific IP block (all asics).
+ * Returns 0 on success, error on failure.
+ */
+int amdgpu_ring_lru_get(struct amdgpu_device *adev, int type,
+                       struct amdgpu_ring **ring)
+{
+       struct amdgpu_ring *entry;
+
+       /* List is sorted in LRU order, find first entry corresponding
+        * to the desired HW IP */
+       *ring = NULL;
+       mutex_lock(&adev->ring_lru_list_lock);
+       list_for_each_entry(entry, &adev->ring_lru_list, lru_list) {
+               if (entry->funcs->type == type) {
+                       *ring = entry;
+                       break;
+               }
+       }
+       mutex_unlock(&adev->ring_lru_list_lock);
+
+       if (!*ring) {
+               DRM_ERROR("Ring LRU contains no entries for ring type:%d\n", 
type);
+               return -EINVAL;
+       }
+
+       amdgpu_ring_lru_touch(adev, entry);
+       return 0;
+}
+
+/**
+ * amdgpu_ring_lru_touch - mark a ring as recently being used
+ *
+ * @adev: amdgpu_device pointer
+ * @ring: ring to touch
+ *
+ * Move @ring to the the tail of the lru list
+ */
+void amdgpu_ring_lru_touch(struct amdgpu_device *adev, struct amdgpu_ring 
*ring)
+{
+       /* list_move_tail handles the case where ring isn't part of the list */
+       mutex_lock(&adev->ring_lru_list_lock);
+       list_move_tail(&ring->lru_list, &adev->ring_lru_list);
+       mutex_unlock(&adev->ring_lru_list_lock);
+}
+
 /*
  * Debugfs info
  */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index 35da5c5..b51bdcd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -144,6 +144,7 @@ struct amdgpu_ring {
        const struct amdgpu_ring_funcs  *funcs;
        struct amdgpu_fence_driver      fence_drv;
        struct amd_gpu_scheduler        sched;
+       struct list_head                lru_list;
 
        struct amdgpu_bo        *ring_obj;
        volatile uint32_t       *ring;
@@ -186,5 +187,8 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct 
amdgpu_ring *ring,
                     unsigned ring_size, struct amdgpu_irq_src *irq_src,
                     unsigned irq_type);
 void amdgpu_ring_fini(struct amdgpu_ring *ring);
+int amdgpu_ring_lru_get(struct amdgpu_device *adev, int hw_ip,
+                       struct amdgpu_ring **ring);
+void amdgpu_ring_lru_touch(struct amdgpu_device *adev, struct amdgpu_ring 
*ring);
 
 #endif
-- 
2.9.3

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to