Reporting objects that are not currently used by the gpu but are dirty and not yet flushed creates havoc to libdrm's bo reuse: The usually immediatly following gtt_map afterwards will stall until the gpu has executed the writeback.
v2: Fix refcount leak and missing unlock in the error path. Spotted by Chris Wilson. Signed-off-by: Daniel Vetter <daniel.vet...@ffwll.ch> --- drivers/gpu/drm/i915/i915_gem.c | 30 +++++++++++++++++++++--------- 1 files changed, 21 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 023f4db..eedc456 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4379,6 +4379,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, struct drm_i915_gem_busy *args = data; struct drm_gem_object *obj; struct drm_i915_gem_object *obj_priv; + int ret = 0; obj = drm_gem_object_lookup(dev, file_priv, args->handle); if (obj == NULL) { @@ -4396,18 +4397,29 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, i915_gem_retire_requests(dev); obj_priv = to_intel_bo(obj); - /* Don't count being on the flushing list against the object being - * done. Otherwise, a buffer left on the flushing list but not getting - * flushed (because nobody's flushing that domain) won't ever return - * unbusy and get reused by libdrm's bo cache. The other expected - * consumer of this interface, OpenGL's occlusion queries, also specs - * that the objects get unbusy "eventually" without any interference. - */ - args->busy = obj_priv->active && obj_priv->last_rendering_seqno != 0; + + /* Count all active objects as busy, even if they are currently not used + * by the gpu. Users of this interface expect objects to eventually + * become non-busy without any further actions, therefore emit any + * necessary flushes here. */ + args->busy = obj_priv->active; + + /* Unconditionally flush objects, even when the gpu still uses this + * object. Userspace calling this function indicates that it wants to + * use this buffer rather sooner than later, so issuing the required + * flush earlier is beneficial. */ + if (obj->write_domain) { + uint32_t seqno; + + i915_gem_flush(dev, 0, obj->write_domain); + seqno = i915_add_request(dev, file_priv, obj->write_domain); + if (seqno == 0) + ret = -ENOMEM; + } drm_gem_object_unreference(obj); mutex_unlock(&dev->struct_mutex); - return 0; + return ret; } int -- 1.6.6.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx