[Mesa-dev] [PATCH 4/4] gallium/hud: handle a thread switch for API-thread-busy monitoring

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

---
 src/gallium/auxiliary/hud/hud_cpu.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/gallium/auxiliary/hud/hud_cpu.c b/src/gallium/auxiliary/hud/hud_cpu.c
index 1cba353..302445d 100644
--- a/src/gallium/auxiliary/hud/hud_cpu.c
+++ b/src/gallium/auxiliary/hud/hud_cpu.c
@@ -237,24 +237,30 @@ struct thread_info {
 
 static void
 query_api_thread_busy_status(struct hud_graph *gr)
 {
    struct thread_info *info = gr->query_data;
    int64_t now = os_time_get_nano();
 
    if (info->last_time) {
       if (info->last_time + gr->pane->period*1000 <= now) {
          int64_t thread_now = pipe_current_thread_get_time_nano();
-
-         hud_graph_add_value(gr,
-                             (thread_now - info->last_thread_time) * 100 /
-                             (now - info->last_time));
+         unsigned percent = (thread_now - info->last_thread_time) * 100 /
+                            (now - info->last_time);
+
+         /* Check if the context changed a thread, so that we don't show
+          * a random value. When a thread is changed, the new thread clock
+          * is different, which can result in "percent" being very high.
+          */
+         if (percent > 100)
+            percent = 0;
+         hud_graph_add_value(gr, percent);
 
          info->last_thread_time = thread_now;
          info->last_time = now;
       }
    } else {
       /* initialize */
       info->last_time = now;
       info->last_thread_time = pipe_current_thread_get_time_nano();
    }
 }
-- 
2.7.4