gpu: nvgpu: gk20a: Add a gpfifo wait trace point

Add a couple of trace points for tracking when we need to wait for
space in the gpfifo ring buffer.  This wait can introduce significant
latencies to rendering with large gpfifo entry inputs so it's good to
be able to measure how often this path is taken.

Bug 1592391
Bug 1550886

Change-Id: I7f362e9c307eeffeeecaaba268ef2e3613e54597
Signed-off-by: Janne Hellsten <jhellsten@nvidia.com>
Reviewed-on: http://git-master/r/674021
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

2 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index b8f769a4..ab0333d6 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -1572,9 +1572,11 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
         /* Make sure we have enough space for gpfifo entries. If not,
          * wait for signals from completed submits */
         if (gp_free_count(c) < num_entries + extra_entries) {
+                trace_gk20a_gpfifo_submit_wait_for_space(c->g->dev->name);
                 err = wait_event_interruptible(c->submit_wq,
                         get_gp_free_count(c) >= num_entries + extra_entries ||
                         c->has_timedout);
+                trace_gk20a_gpfifo_submit_wait_for_space_done(c->g->dev->name);
         }
 
         if (c->has_timedout) {
diff --git a/include/trace/events/gk20a.h b/include/trace/events/gk20a.h
index 8fa8cb94..32e3100a 100644
--- a/include/trace/events/gk20a.h
+++ b/include/trace/events/gk20a.h
@@ -55,6 +55,16 @@ DEFINE_EVENT(gk20a, gk20a_finalize_poweron_done,
         TP_ARGS(name)
 );
 
+DEFINE_EVENT(gk20a, gk20a_gpfifo_submit_wait_for_space,
+        TP_PROTO(const char *name),
+        TP_ARGS(name)
+);
+
+DEFINE_EVENT(gk20a, gk20a_gpfifo_submit_wait_for_space_done,
+        TP_PROTO(const char *name),
+        TP_ARGS(name)
+);
+
 TRACE_EVENT(gk20a_channel_update,
         TP_PROTO(const void *channel),
         TP_ARGS(channel),