[PATCH 21/32] drm/i915: Remove intel_context.active_link

Chris Wilson chris at chris-wilson.co.uk
Wed Apr 10 21:02:55 UTC 2019


We no longer need to track the active intel_contexts within each engine,
allowing us to drop a tricky mutex_lock from inside unpin (which may
occur inside fs_reclaim).

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_context.c           | 11 +----------
 drivers/gpu/drm/i915/gt/intel_context_types.h     |  1 -
 drivers/gpu/drm/i915/i915_debugfs.c               | 13 +++++++++----
 drivers/gpu/drm/i915/i915_gem_context.c           |  2 --
 drivers/gpu/drm/i915/i915_gem_context_types.h     |  1 -
 drivers/gpu/drm/i915/selftests/i915_gem_context.c |  1 -
 drivers/gpu/drm/i915/selftests/mock_context.c     |  1 -
 7 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 5e506e648454..1f1761fc6597 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -49,7 +49,6 @@ int __intel_context_do_pin(struct intel_context *ce)
 		return -EINTR;
 
 	if (likely(!atomic_read(&ce->pin_count))) {
-		struct i915_gem_context *ctx = ce->gem_context;
 		intel_wakeref_t wakeref;
 
 		err = 0;
@@ -58,11 +57,7 @@ int __intel_context_do_pin(struct intel_context *ce)
 		if (err)
 			goto err;
 
-		i915_gem_context_get(ctx);
-
-		mutex_lock(&ctx->mutex);
-		list_add(&ce->active_link, &ctx->active_engines);
-		mutex_unlock(&ctx->mutex);
+		i915_gem_context_get(ce->gem_context); /* for ctx->ppgtt */
 
 		intel_context_get(ce);
 		smp_mb__before_atomic(); /* flush pin before it is visible */
@@ -91,10 +86,6 @@ void intel_context_unpin(struct intel_context *ce)
 	if (likely(atomic_dec_and_test(&ce->pin_count))) {
 		ce->ops->unpin(ce);
 
-		mutex_lock(&ce->gem_context->mutex);
-		list_del(&ce->active_link);
-		mutex_unlock(&ce->gem_context->mutex);
-
 		i915_gem_context_put(ce->gem_context);
 		intel_context_put(ce);
 	}
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 3579c2708321..d5a7dbd0daee 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -38,7 +38,6 @@ struct intel_context {
 	struct intel_engine_cs *engine;
 	struct intel_engine_cs *active;
 
-	struct list_head active_link;
 	struct list_head signal_link;
 	struct list_head signals;
 
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 58956b49f392..6c6bd50d87c9 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -34,6 +34,7 @@
 
 #include "gt/intel_reset.h"
 
+#include "i915_gem_context.h"
 #include "intel_dp.h"
 #include "intel_drv.h"
 #include "intel_fbc.h"
@@ -396,9 +397,11 @@ static void print_context_stats(struct seq_file *m,
 	struct i915_gem_context *ctx;
 
 	list_for_each_entry(ctx, &i915->contexts.list, link) {
-		struct intel_context *ce;
+		struct i915_gem_engines_iter it;
+
+		for_each_gem_engine(it, ctx) {
+			struct intel_context *ce = it.context;
 
-		list_for_each_entry(ce, &ctx->active_engines, active_link) {
 			if (ce->state)
 				per_file_stats(0, ce->state->obj, &kstats);
 			if (ce->ring)
@@ -1893,7 +1896,7 @@ static int i915_context_status(struct seq_file *m, void *unused)
 		return ret;
 
 	list_for_each_entry(ctx, &dev_priv->contexts.list, link) {
-		struct intel_context *ce;
+		struct i915_gem_engines_iter it;
 
 		seq_puts(m, "HW context ");
 		if (!list_empty(&ctx->hw_id_link))
@@ -1917,7 +1920,9 @@ static int i915_context_status(struct seq_file *m, void *unused)
 		seq_putc(m, ctx->remap_slice ? 'R' : 'r');
 		seq_putc(m, '\n');
 
-		list_for_each_entry(ce, &ctx->active_engines, active_link) {
+		for_each_gem_engine(it, ctx) {
+			struct intel_context *ce = it.context;
+
 			seq_printf(m, "%s: ", ce->engine->name);
 			if (ce->state)
 				describe_obj(m, ce->state->obj);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 1fcbe39beec0..bd63e4a8b1ec 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -289,7 +289,6 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 {
 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
 	GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
-	GEM_BUG_ON(!list_empty(&ctx->active_engines));
 
 	release_hw_id(ctx);
 	i915_ppgtt_put(ctx->ppgtt);
@@ -416,7 +415,6 @@ __create_context(struct drm_i915_private *dev_priv)
 	list_add_tail(&ctx->link, &dev_priv->contexts.list);
 	ctx->i915 = dev_priv;
 	ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL);
-	INIT_LIST_HEAD(&ctx->active_engines);
 	mutex_init(&ctx->mutex);
 
 	mutex_init(&ctx->engines_mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem_context_types.h b/drivers/gpu/drm/i915/i915_gem_context_types.h
index 1610a74b0283..ccb64f170e49 100644
--- a/drivers/gpu/drm/i915/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/i915_gem_context_types.h
@@ -151,7 +151,6 @@ struct i915_gem_context {
 	atomic_t hw_id_pin_count;
 	struct list_head hw_id_link;
 
-	struct list_head active_engines;
 	struct mutex mutex;
 
 	struct i915_sched_attr sched;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
index 7fd224a4ca4c..deedd1898fe5 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
@@ -1675,7 +1675,6 @@ static int mock_context_barrier(void *arg)
 		goto out;
 	}
 	i915_request_add(rq);
-	GEM_BUG_ON(list_empty(&ctx->active_engines));
 
 	counter = 0;
 	context_barrier_inject_fault = BIT(RCS0);
diff --git a/drivers/gpu/drm/i915/selftests/mock_context.c b/drivers/gpu/drm/i915/selftests/mock_context.c
index 71c750693585..10e67c931ed1 100644
--- a/drivers/gpu/drm/i915/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/selftests/mock_context.c
@@ -50,7 +50,6 @@ mock_context(struct drm_i915_private *i915,
 	INIT_RADIX_TREE(&ctx->handles_vma, GFP_KERNEL);
 	INIT_LIST_HEAD(&ctx->handles_list);
 	INIT_LIST_HEAD(&ctx->hw_id_link);
-	INIT_LIST_HEAD(&ctx->active_engines);
 	mutex_init(&ctx->mutex);
 
 	ret = i915_gem_context_pin_hw_id(ctx);
-- 
2.20.1



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