[Mesa-dev] [PATCH] [RFC] mesa/glthread: Call unmarshal_batch directly in glthread_finish when batch queue is empty.

[Bartosz Tomczyk]

This avoids costly thread synchronisation. With this fix games that previously regressed with mesa_glthread=true like xonotic or grid autosport.
Could someone test if games that benefit from glthread didn't regress?
---
 src/mesa/main/glthread.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/mesa/main/glthread.c b/src/mesa/main/glthread.c
index 06115b916d..d46288c242 100644
--- a/src/mesa/main/glthread.c
+++ b/src/mesa/main/glthread.c
@@ -252,12 +252,21 @@ _mesa_glthread_finish(struct gl_context *ctx)
    if (pthread_self() == glthread->thread)
       return;
 
-   _mesa_glthread_flush_batch(ctx);
-
    pthread_mutex_lock(&glthread->mutex);
 
-   while (glthread->batch_queue || glthread->busy)
-      pthread_cond_wait(&glthread->work_done, &glthread->mutex);
+   if (!(glthread->batch_queue || glthread->busy))
+   {
+      if (glthread->batch && glthread->batch->used)
+      {
+         glthread_unmarshal_batch(ctx, glthread->batch);
+      }
+      glthread_allocate_batch(ctx);
+   }
+   else
+   {
+      while (glthread->batch_queue || glthread->busy)
+         pthread_cond_wait(&glthread->work_done, &glthread->mutex);
+   }
 
    pthread_mutex_unlock(&glthread->mutex);
 }
-- 
2.12.2