[Mesa-dev] [PATCH 3/5] i965/query: Remove redundant drm_intel_bo_references call in CheckQuery.

Kenneth Graunke kenneth at whitecape.org
Fri Dec 12 23:15:40 PST 2014

CheckQuery calls drm_intel_bo_references to see if the batch references
the query BO, and if so, flushes.  It then checks if the query BO is
busy, and if not, calls gen6_queryobj_get_results().

Stupidly, gen6_queryobj_get_results() immediately did a second redundant
drm_intel_bo_references check, even though we know the buffer is not
referenced and in fact idle.

This patch moves the batch-flush check out of gen6_queryobj_get_results
and into WaitQuery() (the other caller).  That way, both callers do a
single batch-flush check.

This should only be a minor improvement, since it would only affect
the first CheckQuery call where the result is actually available.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86969
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Eero Tamminen <eero.t.tamminen at intel.com>
 src/mesa/drivers/dri/i965/gen6_queryobj.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen6_queryobj.c b/src/mesa/drivers/dri/i965/gen6_queryobj.c
index 537c1d9..9d2e5c4 100644
--- a/src/mesa/drivers/dri/i965/gen6_queryobj.c
+++ b/src/mesa/drivers/dri/i965/gen6_queryobj.c
@@ -121,13 +121,6 @@ gen6_queryobj_get_results(struct gl_context *ctx,
    if (query->bo == NULL)
-   /* If the application has requested the query result, but this batch is
-    * still contributing to it, flush it now so the results will be present
-    * when mapped.
-    */
-   if (drm_intel_bo_references(brw->batch.bo, query->bo))
-      intel_batchbuffer_flush(brw);
    if (unlikely(brw->perf_debug)) {
       if (drm_intel_bo_busy(query->bo)) {
          perf_debug("Stalling on the GPU waiting for a query object.\n");
@@ -304,8 +297,16 @@ gen6_end_query(struct gl_context *ctx, struct gl_query_object *q)
 static void gen6_wait_query(struct gl_context *ctx, struct gl_query_object *q)
+   struct brw_context *brw = brw_context(ctx);
    struct brw_query_object *query = (struct brw_query_object *)q;
+   /* If the application has requested the query result, but this batch is
+    * still contributing to it, flush it now to finish that work so the
+    * result will become available (eventually).
+    */
+   if (drm_intel_bo_references(brw->batch.bo, query->bo))
+      intel_batchbuffer_flush(brw);
    gen6_queryobj_get_results(ctx, query);

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