drm/i915/gem: Drop free_work for GEM contexts

The free_list and worker was introduced in commit 5f09a9c8ab6b ("drm/i915:
Allow contexts to be unreferenced locklessly"), but subsequently made
redundant by the removal of the last sleeping lock in commit 2935ed5339c4
("drm/i915: Remove logical HW ID"). As we can now free the GEM context
immediately from any context, remove the deferral of the free_list

v2: Lift removing the context from the global list into close().

Suggested-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201215152138.8158-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index ad136d009d9b22e9de64f29986f436d07d1162da..738a07b3583cf7fea1d756c98d31344e7921498a 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -334,13 +334,12 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx)
        return e;
 }
 
-static void i915_gem_context_free(struct i915_gem_context *ctx)
+void i915_gem_context_release(struct kref *ref)
 {
-       GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
+       struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref);
 
-       spin_lock(&ctx->i915->gem.contexts.lock);
-       list_del(&ctx->link);
-       spin_unlock(&ctx->i915->gem.contexts.lock);
+       trace_i915_context_free(ctx);
+       GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
 
        mutex_destroy(&ctx->engines_mutex);
        mutex_destroy(&ctx->lut_mutex);
@@ -354,37 +353,6 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
        kfree_rcu(ctx, rcu);
 }
 
-static void contexts_free_all(struct llist_node *list)
-{
-       struct i915_gem_context *ctx, *cn;
-
-       llist_for_each_entry_safe(ctx, cn, list, free_link)
-               i915_gem_context_free(ctx);
-}
-
-static void contexts_flush_free(struct i915_gem_contexts *gc)
-{
-       contexts_free_all(llist_del_all(&gc->free_list));
-}
-
-static void contexts_free_worker(struct work_struct *work)
-{
-       struct i915_gem_contexts *gc =
-               container_of(work, typeof(*gc), free_work);
-
-       contexts_flush_free(gc);
-}
-
-void i915_gem_context_release(struct kref *ref)
-{
-       struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref);
-       struct i915_gem_contexts *gc = &ctx->i915->gem.contexts;
-
-       trace_i915_context_free(ctx);
-       if (llist_add(&ctx->free_link, &gc->free_list))
-               schedule_work(&gc->free_work);
-}
-
 static inline struct i915_gem_engines *
 __context_engines_static(const struct i915_gem_context *ctx)
 {
@@ -633,6 +601,10 @@ static void context_close(struct i915_gem_context *ctx)
         */
        lut_close(ctx);
 
+       spin_lock(&ctx->i915->gem.contexts.lock);
+       list_del(&ctx->link);
+       spin_unlock(&ctx->i915->gem.contexts.lock);
+
        mutex_unlock(&ctx->mutex);
 
        /*
@@ -850,9 +822,6 @@ i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags)
            !HAS_EXECLISTS(i915))
                return ERR_PTR(-EINVAL);
 
-       /* Reap the stale contexts */
-       contexts_flush_free(&i915->gem.contexts);
-
        ctx = __create_context(i915);
        if (IS_ERR(ctx))
                return ctx;
@@ -897,9 +866,6 @@ static void init_contexts(struct i915_gem_contexts *gc)
 {
        spin_lock_init(&gc->lock);
        INIT_LIST_HEAD(&gc->list);
-
-       INIT_WORK(&gc->free_work, contexts_free_worker);
-       init_llist_head(&gc->free_list);
 }
 
 void i915_gem_init__contexts(struct drm_i915_private *i915)
@@ -907,12 +873,6 @@ void i915_gem_init__contexts(struct drm_i915_private *i915)
        init_contexts(&i915->gem.contexts);
 }
 
-void i915_gem_driver_release__contexts(struct drm_i915_private *i915)
-{
-       flush_work(&i915->gem.contexts.free_work);
-       rcu_barrier(); /* and flush the left over RCU frees */
-}
-
 static int gem_context_register(struct i915_gem_context *ctx,
                                struct drm_i915_file_private *fpriv,
                                u32 *id)
@@ -986,7 +946,6 @@ err:
 void i915_gem_context_close(struct drm_file *file)
 {
        struct drm_i915_file_private *file_priv = file->driver_priv;
-       struct drm_i915_private *i915 = file_priv->dev_priv;
        struct i915_address_space *vm;
        struct i915_gem_context *ctx;
        unsigned long idx;
@@ -998,8 +957,6 @@ void i915_gem_context_close(struct drm_file *file)
        xa_for_each(&file_priv->vm_xa, idx, vm)
                i915_vm_put(vm);
        xa_destroy(&file_priv->vm_xa);
-
-       contexts_flush_free(&i915->gem.contexts);
 }
 
 int i915_gem_vm_create_ioctl(struct drm_device *dev, void *data,

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index a133f92bbedb7a51a958138030b2713a2642549f..b5c908f3f4f22a1fba5806b3a5e94f82820dd876 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -110,7 +110,6 @@ i915_gem_context_clear_user_engines(struct i915_gem_context *ctx)
 
 /* i915_gem_context.c */
 void i915_gem_init__contexts(struct drm_i915_private *i915);
-void i915_gem_driver_release__contexts(struct drm_i915_private *i915);
 
 int i915_gem_context_open(struct drm_i915_private *i915,
                          struct drm_file *file);

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
index ae14ca24a11f2e425a6da93adc067f7163e70453..1449f54924e03086be6c9dfb2d03c548c5506fab 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
@@ -108,7 +108,6 @@ struct i915_gem_context {
 
        /** link: place with &drm_i915_private.context_list */
        struct list_head link;
-       struct llist_node free_link;
 
        /**
         * @ref: reference count

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2a48de0ed31f5921eaa3b4e9d81f884cec1c91ec..74d0c6517849ad1a16f921de9750fc49fec64edd 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1172,9 +1172,6 @@ struct drm_i915_private {
                struct i915_gem_contexts {
                        spinlock_t lock; /* locks list */
                        struct list_head list;
-
-                       struct llist_head free_list;
-                       struct work_struct free_work;
                } contexts;
 
                /*

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 58276694c848d2e5e2e83e732dffec6538d4f4a7..17a4636ee54270ec7901eb82df869399baf35510 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1207,8 +1207,6 @@ void i915_gem_driver_remove(struct drm_i915_private *dev_priv)
 
 void i915_gem_driver_release(struct drm_i915_private *dev_priv)
 {
-       i915_gem_driver_release__contexts(dev_priv);
-
        intel_gt_driver_release(&dev_priv->gt);
 
        intel_wa_list_free(&dev_priv->gt_wa_list);

diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index e946bd2087d879d8f41d060008844ca931e45946..0188f877cab2c8e262635c14501d3fb3a971d9ac 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -64,8 +64,6 @@ static void mock_device_release(struct drm_device *dev)
        mock_device_flush(i915);
        intel_gt_driver_remove(&i915->gt);
 
-       i915_gem_driver_release__contexts(i915);
-
        i915_gem_drain_workqueue(i915);
        i915_gem_drain_freed_objects(i915);