[PATCH 52/74] drm/i915: "Race-to-idle" on switching to the kernel context
Chris Wilson
chris at chris-wilson.co.uk
Thu Sep 14 17:34:26 UTC 2017
During suspend we want to flush out all active contexts and their
rendering. To do so we queue a request from the kernel's context, once
we know that request is done, we know the GPU is completely idle. To
speed up that switch bump the GPU clocks.
Switching to the kernel context prior to idling is also used to enforce
a barrier before changing OA properties, and when evicting active
rendering from the global GTT. All cases where we do want to
race-to-idle.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: David Weinehall <david.weinehall at linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com>
Tested-by: David Weinehall <david.weinehall at linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 2 +
drivers/gpu/drm/i915/i915_gem.c | 1 +
drivers/gpu/drm/i915/i915_gem_context.c | 68 ++++++++++++++++++++++++---
drivers/gpu/drm/i915/i915_gem_context.h | 5 ++
drivers/gpu/drm/i915/intel_lrc.c | 2 +-
drivers/gpu/drm/i915/intel_ringbuffer.c | 2 +-
drivers/gpu/drm/i915/selftests/mock_context.c | 1 +
7 files changed, 73 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index bf117fbc0d30..7578e1957888 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2461,6 +2461,8 @@ struct drm_i915_private {
struct llist_head free_list;
struct work_struct free_work;
+ struct list_head freed_objects;
+
/* The hw wants to have a stable context identifier for the
* lifetime of the context (for OA, PASID, faults, etc).
* This is limited in execlists to 21 bits.
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ac4b2673578d..cd2f81ac7380 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3329,6 +3329,7 @@ i915_gem_idle_work_handler(struct work_struct *work)
DRM_ERROR("Timeout waiting for engines to idle\n");
intel_engines_mark_idle(dev_priv);
+ i915_gem_contexts_mark_idle(dev_priv);
i915_gem_timelines_mark_idle(dev_priv);
GEM_BUG_ON(!dev_priv->gt.awake);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 5d1ce9536749..488719e6766c 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -93,6 +93,48 @@
#define ALL_L3_SLICES(dev) (1 << NUM_L3_SLICES(dev)) - 1
+struct drm_i915_gem_object *
+i915_gem_context_create_object(struct drm_i915_private *i915,
+ unsigned long size)
+{
+ struct drm_i915_gem_object *obj, *on;
+
+ lockdep_assert_held(&i915->drm.struct_mutex);
+
+ list_for_each_entry_safe(obj, on,
+ &i915->contexts.freed_objects,
+ batch_pool_link) {
+ if (obj->mm.madv != I915_MADV_DONTNEED) {
+ /* Purge the heretic! */
+ list_del(&obj->batch_pool_link);
+ i915_gem_object_put(obj);
+ continue;
+ }
+
+ if (obj->base.size == size) {
+ list_del(&obj->batch_pool_link);
+ obj->mm.madv = I915_MADV_WILLNEED;
+ return obj;
+ }
+ }
+
+ return i915_gem_object_create(i915, size);
+}
+
+void i915_gem_contexts_mark_idle(struct drm_i915_private *i915)
+{
+ struct drm_i915_gem_object *obj, *on;
+
+ lockdep_assert_held(&i915->drm.struct_mutex);
+
+ list_for_each_entry_safe(obj, on,
+ &i915->contexts.freed_objects,
+ batch_pool_link) {
+ list_del(&obj->batch_pool_link);
+ i915_gem_object_put(obj);
+ }
+}
+
static void lut_close(struct i915_gem_context *ctx)
{
struct i915_lut_handle *lut, *ln;
@@ -119,9 +161,10 @@ static void lut_close(struct i915_gem_context *ctx)
static void i915_gem_context_free(struct i915_gem_context *ctx)
{
+ struct drm_i915_private *i915 = ctx->i915;
int i;
- lockdep_assert_held(&ctx->i915->drm.struct_mutex);
+ lockdep_assert_held(&i915->drm.struct_mutex);
GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
i915_ppgtt_put(ctx->ppgtt);
@@ -136,7 +179,11 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
if (ce->ring)
intel_ring_free(ce->ring);
- __i915_gem_object_release_unless_active(ce->state->obj);
+ /* Keep the objects around for quick reuse */
+ GEM_BUG_ON(ce->state->obj->mm.madv != I915_MADV_WILLNEED);
+ ce->state->obj->mm.madv = I915_MADV_DONTNEED;
+ list_add(&ce->state->obj->batch_pool_link,
+ &i915->contexts.freed_objects);
}
kfree(ctx->name);
@@ -144,7 +191,7 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
list_del(&ctx->link);
- ida_simple_remove(&ctx->i915->contexts.hw_ida, ctx->hw_id);
+ ida_simple_remove(&i915->contexts.hw_ida, ctx->hw_id);
kfree_rcu(ctx, rcu);
}
@@ -426,6 +473,7 @@ int i915_gem_contexts_init(struct drm_i915_private *dev_priv)
return 0;
INIT_LIST_HEAD(&dev_priv->contexts.list);
+ INIT_LIST_HEAD(&dev_priv->contexts.freed_objects);
INIT_WORK(&dev_priv->contexts.free_work, contexts_free_worker);
init_llist_head(&dev_priv->contexts.free_list);
@@ -511,12 +559,17 @@ void i915_gem_contexts_fini(struct drm_i915_private *i915)
lockdep_assert_held(&i915->drm.struct_mutex);
+ GEM_BUG_ON(work_pending(&i915->contexts.free_work));
+
/* Keep the context so that we can free it immediately ourselves */
ctx = i915_gem_context_get(fetch_and_zero(&i915->kernel_context));
GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
context_close(ctx);
i915_gem_context_free(ctx);
+ i915_gem_contexts_mark_idle(i915);
+ GEM_BUG_ON(!list_empty(&i915->contexts.freed_objects));
+
/* Must free all deferred contexts (via flush_workqueue) first */
ida_destroy(&i915->contexts.hw_ida);
}
@@ -894,6 +947,7 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *dev_priv)
for_each_engine(engine, dev_priv, id) {
struct drm_i915_gem_request *req;
+ bool active = false;
if (engine_has_kernel_context(engine))
continue;
@@ -911,11 +965,13 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *dev_priv)
prev = i915_gem_active_raw(&tl->last_request,
&dev_priv->drm.struct_mutex);
if (prev)
- i915_sw_fence_await_sw_fence_gfp(&req->submit,
- &prev->submit,
- GFP_KERNEL);
+ active |= i915_sw_fence_await_sw_fence_gfp(&req->submit,
+ &prev->submit,
+ GFP_KERNEL) > 0;
}
+ if (active)
+ gen6_rps_boost(req, NULL);
i915_add_request(req);
}
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
index 44688e22a5c2..baa111749c85 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -281,6 +281,11 @@ void i915_gem_context_release(struct kref *ctx_ref);
struct i915_gem_context *
i915_gem_context_create_gvt(struct drm_device *dev);
+struct drm_i915_gem_object *
+i915_gem_context_create_object(struct drm_i915_private *i915,
+ unsigned long size);
+void i915_gem_contexts_mark_idle(struct drm_i915_private *i915);
+
int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 95188b4ce33f..3adf7c411d5c 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2153,7 +2153,7 @@ static int execlists_context_deferred_alloc(struct i915_gem_context *ctx,
*/
context_size += LRC_HEADER_PAGES * PAGE_SIZE;
- ctx_obj = i915_gem_object_create(ctx->i915, context_size);
+ ctx_obj = i915_gem_context_create_object(ctx->i915, context_size);
if (IS_ERR(ctx_obj)) {
DRM_DEBUG_DRIVER("Alloc LRC backing obj failed.\n");
return PTR_ERR(ctx_obj);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 8581242bcac0..a31b07417311 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1352,7 +1352,7 @@ alloc_context_vma(struct intel_engine_cs *engine)
struct drm_i915_gem_object *obj;
struct i915_vma *vma;
- obj = i915_gem_object_create(i915, engine->context_size);
+ obj = i915_gem_context_create_object(i915, engine->context_size);
if (IS_ERR(obj))
return ERR_CAST(obj);
diff --git a/drivers/gpu/drm/i915/selftests/mock_context.c b/drivers/gpu/drm/i915/selftests/mock_context.c
index 098ce643ad07..082202e70ddc 100644
--- a/drivers/gpu/drm/i915/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/selftests/mock_context.c
@@ -85,6 +85,7 @@ void mock_init_contexts(struct drm_i915_private *i915)
INIT_LIST_HEAD(&i915->contexts.list);
ida_init(&i915->contexts.hw_ida);
+ INIT_LIST_HEAD(&i915->contexts.freed_objects);
INIT_WORK(&i915->contexts.free_work, contexts_free_worker);
init_llist_head(&i915->contexts.free_list);
}
--
2.14.1
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