spdk_top: add rpc for scheduler and governor

Added rpc to get name and period of currently set spdk scheduler
and name of currently set spdk governor.

Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com>
Change-Id: I5562a81a7f9e4879bd48a765c9467f70b43f73ab
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5917
Community-CI: Broadcom CI
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: Maciej Szwed <maciej.szwed@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

doc/jsonrpc.md

@@ -727,6 +727,48 @@ Example response:
 }
 ~~~
 
+### framework_get_scheduler {#rpc_framework_get_scheduler}
+
+Retrieve currently set scheduler name and period, along with current governor name.
+
+### Parameters
+
+This method has no parameters.
+
+### Response
+
+Name                    | Description
+------------------------| -----------
+scheduler_name          | Current scheduler name
+scheduler_period        | Currently set scheduler period in microseconds
+governor_name           | Governor name
+
+### Example
+
+Example request:
+
+~~~
+{
+  "jsonrpc": "2.0",
+  "method": "framework_set_scheduler",
+  "id": 1,
+}
+~~~
+
+Example response:
+
+~~~
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": {
+    "scheduler name": "static",
+    "scheduler period": 2800000000,
+    "governor name": "default"
+  }
+}
+~~~
+
 ## thread_get_stats {#rpc_thread_get_stats}
 
 Retrieve current statistics of all the threads.

include/spdk_internal/event.h

@@ -253,6 +253,12 @@ void _spdk_governor_list_add(struct spdk_governor *governor);
  */
 int _spdk_governor_set(char *name);
 
+/**
+ * Get currently set governor.
+ *
+ */
+struct spdk_governor *_spdk_governor_get(void);
+
 /**
  * Macro used to register new cores governor.
  */
@@ -320,6 +326,12 @@ void _spdk_scheduler_list_add(struct spdk_scheduler *scheduler);
  */
 int _spdk_scheduler_set(char *name);
 
+/**
+ * Get currently set scheduler.
+ *
+ */
+struct spdk_scheduler *_spdk_scheduler_get(void);
+
 /**
  * Change current scheduling period.
  *
@@ -327,6 +339,11 @@ int _spdk_scheduler_set(char *name);
  */
 void _spdk_scheduler_period_set(uint64_t period);
 
+/**
+ * Get period of currently set scheduler.
+ */
+uint64_t _spdk_scheduler_period_get(void);
+
 /*
  * Macro used to register new reactor balancer.
  */

lib/event/app_rpc.c

@@ -480,6 +480,31 @@ end:
 }
 SPDK_RPC_REGISTER("framework_set_scheduler", rpc_framework_set_scheduler, SPDK_RPC_STARTUP)
 
+static void
+rpc_framework_get_scheduler(struct spdk_jsonrpc_request *request,
+			    const struct spdk_json_val *params)
+{
+	struct spdk_json_write_ctx *w;
+	struct spdk_scheduler *scheduler = _spdk_scheduler_get();
+	uint64_t scheduler_period = _spdk_scheduler_period_get();
+	struct spdk_governor *governor = _spdk_governor_get();
+
+	if (params) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
+						 "'rpc_get_scheduler' requires no arguments");
+		return;
+	}
+
+	w = spdk_jsonrpc_begin_result(request);
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "scheduler name", scheduler->name);
+	spdk_json_write_named_uint64(w, "scheduler period", scheduler_period);
+	spdk_json_write_named_string(w, "governor name", governor->name);
+	spdk_json_write_object_end(w);
+	spdk_jsonrpc_end_result(request, w);
+}
+SPDK_RPC_REGISTER("framework_get_scheduler", rpc_framework_get_scheduler, SPDK_RPC_RUNTIME)
+
 struct rpc_thread_set_cpumask_ctx {
 	struct spdk_jsonrpc_request *request;
 	struct spdk_cpuset cpumask;

lib/event/reactor.c

@@ -132,6 +132,19 @@ _spdk_scheduler_set(char *name)
 	return 0;
 }
 
+struct spdk_scheduler *
+_spdk_scheduler_get(void)
+{
+	return g_scheduler;
+}
+
+uint64_t
+_spdk_scheduler_period_get(void)
+{
+	/* Convert from ticks to microseconds */
+	return (g_scheduler_period * SPDK_SEC_TO_USEC / spdk_get_ticks_hz());
+}
+
 void
 _spdk_scheduler_period_set(uint64_t period)
 {
@@ -1250,6 +1263,12 @@ _spdk_governor_set(char *name)
 	return 0;
 }
 
+struct spdk_governor *
+_spdk_governor_get(void)
+{
+	return &g_governor;
+}
+
 void
 _spdk_governor_list_add(struct spdk_governor *governor)
 {

scripts/rpc.py

@@ -168,6 +168,13 @@ if __name__ == "__main__":
     p.add_argument('-p', '--period', help="Scheduler period in microseconds", type=int)
     p.set_defaults(func=framework_set_scheduler)
 
+    def framework_get_scheduler(args):
+        print_dict(rpc.app.framework_get_scheduler(args.client))
+
+    p = subparsers.add_parser(
+        'framework_get_scheduler', help='Display currently set scheduler and its properties.')
+    p.set_defaults(func=framework_get_scheduler)
+
     # bdev
     def bdev_set_options(args):
         rpc.bdev.bdev_set_options(args.client,

scripts/rpc/app.py

@@ -52,6 +52,15 @@ def framework_set_scheduler(client, name, period=None):
     return client.call('framework_set_scheduler', params)
 
 
+def framework_get_scheduler(client):
+    """Query currently set scheduler.
+
+    Returns:
+        Name, period (in microseconds) of currently set scheduler and name of curently set governor.
+    """
+    return client.call('framework_get_scheduler')
+
+
 def thread_get_stats(client):
     """Query threads statistics.