Better HTTP stats

src/core/ext/transport/chttp2/transport/chttp2_transport.c

@@ -940,6 +940,9 @@ static void write_action_begin_locked(grpc_exec_ctx *exec_ctx, void *gt,
   if (r.writing) {
     grpc_closure_scheduler *scheduler =
         write_scheduler(t, r.early_results_scheduled, r.partial);
+    if (scheduler != grpc_schedule_on_exec_ctx) {
+      GRPC_STATS_INC_HTTP2_WRITES_OFFLOADED(exec_ctx);
+    }
     set_write_state(
         exec_ctx, t, r.partial ? GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE
                                : GRPC_CHTTP2_WRITE_STATE_WRITING,

src/core/lib/debug/stats_data.c

@@ -42,6 +42,7 @@ const char *grpc_stats_counter_name[GRPC_STATS_COUNTER_COUNT] = {
     "http2_op_recv_trailing_metadata",
     "http2_pings_sent",
     "http2_writes_begun",
+    "http2_writes_offloaded",
     "combiner_locks_initiated",
     "combiner_locks_scheduled_items",
     "combiner_locks_scheduled_final_items",

src/core/lib/debug/stats_data.h

@@ -44,6 +44,7 @@ typedef enum {
   GRPC_STATS_COUNTER_HTTP2_OP_RECV_TRAILING_METADATA,
   GRPC_STATS_COUNTER_HTTP2_PINGS_SENT,
   GRPC_STATS_COUNTER_HTTP2_WRITES_BEGUN,
+  GRPC_STATS_COUNTER_HTTP2_WRITES_OFFLOADED,
   GRPC_STATS_COUNTER_COMBINER_LOCKS_INITIATED,
   GRPC_STATS_COUNTER_COMBINER_LOCKS_SCHEDULED_ITEMS,
   GRPC_STATS_COUNTER_COMBINER_LOCKS_SCHEDULED_FINAL_ITEMS,
@@ -125,6 +126,8 @@ typedef enum {
   GRPC_STATS_INC_COUNTER((exec_ctx), GRPC_STATS_COUNTER_HTTP2_PINGS_SENT)
 #define GRPC_STATS_INC_HTTP2_WRITES_BEGUN(exec_ctx) \
   GRPC_STATS_INC_COUNTER((exec_ctx), GRPC_STATS_COUNTER_HTTP2_WRITES_BEGUN)
+#define GRPC_STATS_INC_HTTP2_WRITES_OFFLOADED(exec_ctx) \
+  GRPC_STATS_INC_COUNTER((exec_ctx), GRPC_STATS_COUNTER_HTTP2_WRITES_OFFLOADED)
 #define GRPC_STATS_INC_COMBINER_LOCKS_INITIATED(exec_ctx) \
   GRPC_STATS_INC_COUNTER((exec_ctx),                      \
                          GRPC_STATS_COUNTER_COMBINER_LOCKS_INITIATED)

src/core/lib/debug/stats_data.yaml

@@ -57,6 +57,7 @@
   buckets: 64
 - counter: http2_pings_sent
 - counter: http2_writes_begun
+- counter: http2_writes_offloaded
 # combiner locks
 - counter: combiner_locks_initiated
 - counter: combiner_locks_scheduled_items