As the VM do not track activity of objects and instead use a large
hammer to forcibly idle and evict all of their associated objects when
one is released, it is possible for that to cause a recursion when we
need to wait for free space on a ring and call retire requests.
(intel_ring_begin -> intel_ring_wait_request ->
i915_gem_retire_requests_ring -> i915_gem_context_free ->
i915_gem_evict_vm -> i915_gpu_idle -> intel_ring_begin etc)
In order to remove the requirement for calling retire-requests from
intel_ring_wait_request, we have to inline a couple of steps from
retiring requests, notably we have to record the position of the request
we wait for and use that to update the available ring space.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 25 +++++--------------------
1 file changed, 5 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 10ff32d09c14..0da7c257159a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1431,28 +1431,16 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
cleanup_status_page(ring);
}
-static int intel_ring_wait_seqno(struct intel_ring_buffer *ring, u32 seqno)
-{
- int ret;
-
- ret = i915_wait_seqno(ring, seqno);
- if (!ret)
- i915_gem_retire_requests_ring(ring);
-
- return ret;
-}
-
static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
{
struct drm_i915_gem_request *request;
- u32 seqno = 0;
+ u32 seqno = 0, tail;
int ret;
- i915_gem_retire_requests_ring(ring);
-
if (ring->last_retired_head != -1) {
ring->head = ring->last_retired_head;
ring->last_retired_head = -1;
+
ring->space = ring_space(ring);
if (ring->space >= n)
return 0;
@@ -1469,6 +1457,7 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
space += ring->size;
if (space >= n) {
seqno = request->seqno;
+ tail = request->tail;
break;
}
@@ -1483,15 +1472,11 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n)
if (seqno == 0)
return -ENOSPC;
- ret = intel_ring_wait_seqno(ring, seqno);
+ ret = i915_wait_seqno(ring, seqno);
if (ret)
return ret;
- if (WARN_ON(ring->last_retired_head == -1))
- return -ENOSPC;
-
- ring->head = ring->last_retired_head;
- ring->last_retired_head = -1;
+ ring->head = tail;
ring->space = ring_space(ring);
if (WARN_ON(ring->space < n))
return -ENOSPC;
--
1.8.5.3
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
