Merge pull request #11532 from ctiller/optimize_for

Allow application optimization targets to be hinted to grpc (prefer latency over throughput for now)

3 files changed, 33 insertions, 2 deletions

diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 6e8eadf7a1..9157170f52 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -34,6 +34,7 @@
 #include "src/core/ext/transport/chttp2/transport/varint.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/http/parser.h"
+#include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
@@ -280,8 +281,6 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   grpc_slice_buffer_init(&t->outbuf);
   grpc_chttp2_hpack_compressor_init(&t->hpack_compressor);
 
-  GRPC_CLOSURE_INIT(&t->write_action, write_action, t,
-                    grpc_schedule_on_exec_ctx);
   GRPC_CLOSURE_INIT(&t->read_action_locked, read_action_locked, t,
                     grpc_combiner_scheduler(t->combiner));
   GRPC_CLOSURE_INIT(&t->benign_reclaimer_locked, benign_reclaimer_locked, t,
@@ -399,6 +398,8 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   }
   t->keepalive_permit_without_calls = g_default_keepalive_permit_without_calls;
 
+  t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY;
+
   if (channel_args) {
     for (i = 0; i < channel_args->num_args; i++) {
       if (0 == strcmp(channel_args->args[i].key,
@@ -487,6 +488,23 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
         t->keepalive_permit_without_calls =
             (uint32_t)grpc_channel_arg_get_integer(
                 &channel_args->args[i], (grpc_integer_options){0, 0, 1});
+      } else if (0 == strcmp(channel_args->args[i].key,
+                             GRPC_ARG_OPTIMIZATION_TARGET)) {
+        if (channel_args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s should be a string",
+                  GRPC_ARG_OPTIMIZATION_TARGET);
+        } else if (0 == strcmp(channel_args->args[i].value.string, "blend")) {
+          t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY;
+        } else if (0 == strcmp(channel_args->args[i].value.string, "latency")) {
+          t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY;
+        } else if (0 ==
+                   strcmp(channel_args->args[i].value.string, "throughput")) {
+          t->opt_target = GRPC_CHTTP2_OPTIMIZE_FOR_THROUGHPUT;
+        } else {
+          gpr_log(GPR_ERROR, "%s value '%s' unknown, assuming 'blend'",
+                  GRPC_ARG_OPTIMIZATION_TARGET,
+                  channel_args->args[i].value.string);
+        }
       } else {
         static const struct {
           const char *channel_arg_name;
@@ -540,6 +558,11 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     }
   }
 
+  GRPC_CLOSURE_INIT(&t->write_action, write_action, t,
+                    t->opt_target == GRPC_CHTTP2_OPTIMIZE_FOR_THROUGHPUT
+                        ? grpc_executor_scheduler
+                        : grpc_schedule_on_exec_ctx);
+
   t->ping_state.pings_before_data_required =
       t->ping_policy.max_pings_without_data;
   t->ping_state.is_delayed_ping_timer_set = false;
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 9fa72ddbdf..a5b67e5aba 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -67,6 +67,11 @@ typedef enum {
 } grpc_chttp2_ping_type;
 
 typedef enum {
+  GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY,
+  GRPC_CHTTP2_OPTIMIZE_FOR_THROUGHPUT,
+} grpc_chttp2_optimization_target;
+
+typedef enum {
   GRPC_CHTTP2_PCL_INITIATE = 0,
   GRPC_CHTTP2_PCL_NEXT,
   GRPC_CHTTP2_PCL_INFLIGHT,
@@ -229,6 +234,8 @@ struct grpc_chttp2_transport {
   /** should we probe bdp? */
   bool enable_bdp_probe;
 
+  grpc_chttp2_optimization_target opt_target;
+
   /** various lists of streams */
   grpc_chttp2_stream_list lists[STREAM_LIST_COUNT];
 
diff --git a/src/proto/grpc/testing/control.proto b/src/proto/grpc/testing/control.proto
index 4252a6f090..48016642f7 100644
--- a/src/proto/grpc/testing/control.proto
+++ b/src/proto/grpc/testing/control.proto
@@ -152,6 +152,7 @@ message ServerConfig {
 
   // Buffer pool size (no buffer pool specified if unset)
   int32 resource_quota_size = 1001;
+  repeated ChannelArg channel_args = 1002;
 }
 
 message ServerArgs {