[intel] Re-allocate backing buffer objects on BufferData.

This may allow better concurrency (noop in openarena performance now), but is
also important for the previous commit -- otherwise, we may end up with
BufferData, draw_prims, BufferData and the draw_prims would use the new VBO
data instead of old.  This could still occur with user-supplied VBOs and poor
use of MapBuffer without BufferData.

1 files changed, 2 insertions, 9 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_buffer_objects.c b/src/mesa/drivers/dri/intel/intel_buffer_objects.c
index 89b489e28a..bd1b2ca1b1 100644
--- a/src/mesa/drivers/dri/intel/intel_buffer_objects.c
+++ b/src/mesa/drivers/dri/intel/intel_buffer_objects.c
@@ -135,19 +135,12 @@ intel_bufferobj_data(GLcontext * ctx,
    if (intel_obj->region)
       intel_bufferobj_release_region(intel, intel_obj);
 
-   /* While it would seem to make sense to always reallocate the buffer here,
-    * since it should allow us better concurrency between rendering and
-    * map-cpu write-unmap, doing so was a minor (~10%) performance loss
-    * for both classic and TTM mode with openarena.  That may change with
-    * improved buffer manager algorithms.
-    */
-   if (intel_obj->buffer != NULL && intel_obj->buffer->size != size) {
+   if (intel_obj->buffer != NULL) {
       dri_bo_unreference(intel_obj->buffer);
       intel_obj->buffer = NULL;
    }
    if (size != 0) {
-      if (intel_obj->buffer == NULL)
-	 intel_bufferobj_alloc_buffer(intel, intel_obj);
+      intel_bufferobj_alloc_buffer(intel, intel_obj);
 
       if (data != NULL)
 	 dri_bo_subdata(intel_obj->buffer, 0, size, data);