From f8a7fde4561067a8ebc956b27afeb530ac97cb9d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 28 Oct 2016 13:58:29 +0100 Subject: [PATCH] drm/i915: Defer active reference until required We only need the active reference to keep the object alive after the handle has been deleted (so as to prevent a synchronous gem_close). Why then pay the price of a kref on every execbuf when we can insert that final active ref just in time for the handle deletion? Signed-off-by: Chris Wilson Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-6-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_drv.h | 28 ++++++++++++++++++++ drivers/gpu/drm/i915/i915_gem.c | 22 ++++++++++++++- drivers/gpu/drm/i915/i915_gem_batch_pool.c | 2 +- drivers/gpu/drm/i915/i915_gem_context.c | 2 +- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 -- drivers/gpu/drm/i915/i915_gem_gtt.c | 7 ++++- drivers/gpu/drm/i915/i915_gem_render_state.c | 3 ++- drivers/gpu/drm/i915/intel_ringbuffer.c | 15 ++++++++--- 8 files changed, 71 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index cf4b2427aff3..edc59d08d017 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2246,6 +2246,12 @@ struct drm_i915_gem_object { #define __I915_BO_ACTIVE(bo) \ ((READ_ONCE((bo)->flags) >> I915_BO_ACTIVE_SHIFT) & I915_BO_ACTIVE_MASK) + /** + * Have we taken a reference for the object for incomplete GPU + * activity? + */ +#define I915_BO_ACTIVE_REF (I915_BO_ACTIVE_SHIFT + I915_NUM_ENGINES) + /** * This is set if the object has been written to since last bound * to the GTT @@ -2407,6 +2413,28 @@ i915_gem_object_has_active_engine(const struct drm_i915_gem_object *obj, return obj->flags & BIT(engine + I915_BO_ACTIVE_SHIFT); } +static inline bool +i915_gem_object_has_active_reference(const struct drm_i915_gem_object *obj) +{ + return test_bit(I915_BO_ACTIVE_REF, &obj->flags); +} + +static inline void +i915_gem_object_set_active_reference(struct drm_i915_gem_object *obj) +{ + lockdep_assert_held(&obj->base.dev->struct_mutex); + __set_bit(I915_BO_ACTIVE_REF, &obj->flags); +} + +static inline void +i915_gem_object_clear_active_reference(struct drm_i915_gem_object *obj) +{ + lockdep_assert_held(&obj->base.dev->struct_mutex); + __clear_bit(I915_BO_ACTIVE_REF, &obj->flags); +} + +void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj); + static inline unsigned int i915_gem_object_get_tiling(struct drm_i915_gem_object *obj) { diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 537f502123ea..c0103044dede 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2661,7 +2661,10 @@ i915_gem_object_retire__read(struct i915_gem_active *active, list_move_tail(&obj->global_list, &request->i915->mm.bound_list); - i915_gem_object_put(obj); + if (i915_gem_object_has_active_reference(obj)) { + i915_gem_object_clear_active_reference(obj); + i915_gem_object_put(obj); + } } static bool i915_context_is_banned(const struct i915_gem_context *ctx) @@ -2935,6 +2938,12 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file) list_for_each_entry_safe(vma, vn, &obj->vma_list, obj_link) if (vma->vm->file == fpriv) i915_vma_close(vma); + + if (i915_gem_object_is_active(obj) && + !i915_gem_object_has_active_reference(obj)) { + i915_gem_object_set_active_reference(obj); + i915_gem_object_get(obj); + } mutex_unlock(&obj->base.dev->struct_mutex); } @@ -4475,6 +4484,17 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj) intel_runtime_pm_put(dev_priv); } +void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj) +{ + lockdep_assert_held(&obj->base.dev->struct_mutex); + + GEM_BUG_ON(i915_gem_object_has_active_reference(obj)); + if (i915_gem_object_is_active(obj)) + i915_gem_object_set_active_reference(obj); + else + i915_gem_object_put(obj); +} + int i915_gem_suspend(struct drm_device *dev) { struct drm_i915_private *dev_priv = to_i915(dev); diff --git a/drivers/gpu/drm/i915/i915_gem_batch_pool.c b/drivers/gpu/drm/i915/i915_gem_batch_pool.c index ed989596d9a3..cb25cad3318c 100644 --- a/drivers/gpu/drm/i915/i915_gem_batch_pool.c +++ b/drivers/gpu/drm/i915/i915_gem_batch_pool.c @@ -73,7 +73,7 @@ void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool) list_for_each_entry_safe(obj, next, &pool->cache_list[n], batch_pool_link) - i915_gem_object_put(obj); + __i915_gem_object_release_unless_active(obj); INIT_LIST_HEAD(&pool->cache_list[n]); } diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 5dca32ac1c67..47e888cc721f 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -155,7 +155,7 @@ void i915_gem_context_free(struct kref *ctx_ref) if (ce->ring) intel_ring_free(ce->ring); - i915_vma_put(ce->state); + __i915_gem_object_release_unless_active(ce->state->obj); } put_pid(ctx->pid); diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 61365ae22b53..4cafce97998a 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1290,8 +1290,6 @@ void i915_vma_move_to_active(struct i915_vma *vma, * add the active reference first and queue for it to be dropped * *last*. */ - if (!i915_gem_object_is_active(obj)) - i915_gem_object_get(obj); i915_gem_object_set_active(obj, idx); i915_gem_active_set(&obj->last_read[idx], req); diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 947d5ad51fb7..a3a364478a89 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -3734,11 +3734,16 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma) void i915_vma_unpin_and_release(struct i915_vma **p_vma) { struct i915_vma *vma; + struct drm_i915_gem_object *obj; vma = fetch_and_zero(p_vma); if (!vma) return; + obj = vma->obj; + i915_vma_unpin(vma); - i915_vma_put(vma); + i915_vma_close(vma); + + __i915_gem_object_release_unless_active(obj); } diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c index a98c0f42badd..e7c3dbcc6c81 100644 --- a/drivers/gpu/drm/i915/i915_gem_render_state.c +++ b/drivers/gpu/drm/i915/i915_gem_render_state.c @@ -224,7 +224,8 @@ int i915_gem_render_state_init(struct drm_i915_gem_request *req) i915_vma_move_to_active(so.vma, req, 0); err_unpin: i915_vma_unpin(so.vma); + i915_vma_close(so.vma); err_obj: - i915_gem_object_put(obj); + __i915_gem_object_release_unless_active(obj); return ret; } diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 8ef735faa603..8eee9675d3bf 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1762,14 +1762,19 @@ static void cleanup_phys_status_page(struct intel_engine_cs *engine) static void cleanup_status_page(struct intel_engine_cs *engine) { struct i915_vma *vma; + struct drm_i915_gem_object *obj; vma = fetch_and_zero(&engine->status_page.vma); if (!vma) return; + obj = vma->obj; + i915_vma_unpin(vma); - i915_gem_object_unpin_map(vma->obj); - i915_vma_put(vma); + i915_vma_close(vma); + + i915_gem_object_unpin_map(obj); + __i915_gem_object_release_unless_active(obj); } static int init_status_page(struct intel_engine_cs *engine) @@ -1967,7 +1972,11 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size) void intel_ring_free(struct intel_ring *ring) { - i915_vma_put(ring->vma); + struct drm_i915_gem_object *obj = ring->vma->obj; + + i915_vma_close(ring->vma); + __i915_gem_object_release_unless_active(obj); + kfree(ring); } -- 2.39.5