drm/i915: Only track live rings for retiring

We don't need to track every ring for its lifetime as they are managed
by the contexts/engines. What we do want to track are the live rings so
that we can sporadically clean up requests if userspace falls behind. We
can simply restrict the gt->rings list to being only gt->live_rings.

v2: s/live/active/ for consistency with gt.active_requests

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180430131503.5375-4-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index edc33e059191e84b395dc827b30b9244491efd8f..6268a5103dba6eda7494e49e4cc3e02cba30f83b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2061,7 +2061,8 @@ struct drm_i915_private {
 
                struct i915_gem_timeline global_timeline;
                struct list_head timelines;
-               struct list_head rings;
+
+               struct list_head active_rings;
                u32 active_requests;
                u32 request_serial;
 

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f0644d1fbd75028d57d38991d6a3c6d7dde1d09c..fa1d94a4eb5fe49a1ac937c2e9b3b852716718a6 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -141,6 +141,7 @@ static u32 __i915_gem_park(struct drm_i915_private *i915)
 {
        lockdep_assert_held(&i915->drm.struct_mutex);
        GEM_BUG_ON(i915->gt.active_requests);
+       GEM_BUG_ON(!list_empty(&i915->gt.active_rings));
 
        if (!i915->gt.awake)
                return I915_EPOCH_INVALID;
@@ -5599,9 +5600,10 @@ int i915_gem_init_early(struct drm_i915_private *dev_priv)
        if (!dev_priv->priorities)
                goto err_dependencies;
 
-       mutex_lock(&dev_priv->drm.struct_mutex);
-       INIT_LIST_HEAD(&dev_priv->gt.rings);
        INIT_LIST_HEAD(&dev_priv->gt.timelines);
+       INIT_LIST_HEAD(&dev_priv->gt.active_rings);
+
+       mutex_lock(&dev_priv->drm.struct_mutex);
        err = i915_gem_timeline_init__global(dev_priv);
        mutex_unlock(&dev_priv->drm.struct_mutex);
        if (err)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index e6535255d445bf97d16e417bd43745123da53a22..c8fc4b323e6240d3b6c7d96d674f48c2a647f73d 100644 (file)
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -322,6 +322,7 @@ static void advance_ring(struct i915_request *request)
                 * noops - they are safe to be replayed on a reset.
                 */
                tail = READ_ONCE(request->tail);
+               list_del(&ring->active_link);
        } else {
                tail = request->postfix;
        }
@@ -1096,6 +1097,8 @@ void __i915_request_add(struct i915_request *request, bool flush_caches)
        i915_gem_active_set(&timeline->last_request, request);
 
        list_add_tail(&request->ring_link, &ring->request_list);
+       if (list_is_first(&request->ring_link, &ring->request_list))
+               list_add(&ring->active_link, &request->i915->gt.active_rings);
        request->emitted_jiffies = jiffies;
 
        /*
@@ -1418,14 +1421,17 @@ static void ring_retire_requests(struct intel_ring *ring)
 
 void i915_retire_requests(struct drm_i915_private *i915)
 {
-       struct intel_ring *ring, *next;
+       struct intel_ring *ring, *tmp;
 
        lockdep_assert_held(&i915->drm.struct_mutex);
 
        if (!i915->gt.active_requests)
                return;
 
-       list_for_each_entry_safe(ring, next, &i915->gt.rings, link)
+       /* An outstanding request must be on a still active ring somewhere */
+       GEM_BUG_ON(list_empty(&i915->gt.active_rings));
+
+       list_for_each_entry_safe(ring, tmp, &i915->gt.active_rings, active_link)
                ring_retire_requests(ring);
 }
 

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ae8958007df548b6f8109e09b07022eea246b4fb..007449cfa22ba1fc01e41f13940c3eb19b929287 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1150,8 +1150,6 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size)
        }
        ring->vma = vma;
 
-       list_add(&ring->link, &engine->i915->gt.rings);
-
        return ring;
 }
 
@@ -1163,8 +1161,6 @@ intel_ring_free(struct intel_ring *ring)
        i915_vma_close(ring->vma);
        __i915_gem_object_release_unless_active(obj);
 
-       list_del(&ring->link);
-
        kfree(ring);
 }
 

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index deb80d01e0bdd881f7a563129af97baffe7c6f08..fd679cec9ac657942f8149419931a578fade8a15 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -130,7 +130,7 @@ struct intel_ring {
        void *vaddr;
 
        struct list_head request_list;
-       struct list_head link;
+       struct list_head active_link;
 
        u32 head;
        u32 tail;

diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index d95fc481e5c17444f8a1e55d9fe7f1d51b3529d6..19175ddcb45b8d773e2f349d3b959acfc4908a21 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -147,15 +147,11 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
        INIT_LIST_HEAD(&ring->request_list);
        intel_ring_update_space(ring);
 
-       list_add(&ring->link, &engine->i915->gt.rings);
-
        return ring;
 }
 
 static void mock_ring_free(struct intel_ring *ring)
 {
-       list_del(&ring->link);
-
        kfree(ring);
 }
 

diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index ac4bacf8b5b93c8a97355989e94eaf8abecebff5..f22a2b35a283c14cb424dfaa470d43ff6e601ecb 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -224,9 +224,10 @@ struct drm_i915_private *mock_gem_device(void)
        if (!i915->priorities)
                goto err_dependencies;
 
-       mutex_lock(&i915->drm.struct_mutex);
-       INIT_LIST_HEAD(&i915->gt.rings);
        INIT_LIST_HEAD(&i915->gt.timelines);
+       INIT_LIST_HEAD(&i915->gt.active_rings);
+
+       mutex_lock(&i915->drm.struct_mutex);
        err = i915_gem_timeline_init__global(i915);
        if (err) {
                mutex_unlock(&i915->drm.struct_mutex);