lib/trace: add trace_get_info RPC

Add rpc method trace_get_info to show name of shared memory file,
list of the available trace point groups and mask of the available trace points for each group.

Fixes #2747

Signed-off-by: Xinrui Mao <xinrui.mao@intel.com>
Change-Id: I2098283bed454dc46644fd2ca1b9568ab2aea81b
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15426
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <smatsumoto@nvidia.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Xiaodong Liu <xiaodong.liu@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Community-CI: Mellanox Build Bot

CHANGELOG.md

@@ -58,6 +58,11 @@ Added spdk_rpc_set_allowlist to restrict allowed RPCs to the specified list.
 Promoted the application to example to match similar programs: fio_plugin and perf.
 It can now be found inside `examples/bdev/bdevperf`.
 
+### trace
+
+New `trace_get_info` RPC was added to get name of shared memory file, list of the
+available trace point groups and mask of the available trace points for each group.
+
 ### util
 
 New API `spdk_fd_group_get_epoll_event` that returns the epoll(7) event that

doc/jsonrpc.md

@@ -1173,6 +1173,76 @@ Example response:
 }
 ~~~
 
+### trace_get_info {#rpc_trace_get_info}
+
+Get name of shared memory file, list of the available trace point groups
+and mask of the available trace points for each group
+
+#### Parameters
+
+No parameters required
+
+#### Example
+
+Example request:
+
+~~~json
+{
+  "jsonrpc": "2.0",
+  "method": "trace_get_info",
+  "id": 1
+}
+~~~
+
+Example response:
+
+~~~json
+{
+  "jsonrpc": "2.0",
+  "id": 1,
+  "result": {
+    "tpoint_shm_path": "/dev/shm/spdk_tgt_trace.pid3071944",
+    "tpoint_group_mask": "0x8",
+    "iscsi_conn": {
+      "mask": "0x2",
+      "tpoint_mask": "0x0"
+    },
+    "scsi": {
+      "mask": "0x4",
+      "tpoint_mask": "0x0"
+    },
+    "bdev": {
+      "mask": "0x8",
+      "tpoint_mask": "0xffffffffffffffff"
+    },
+    "nvmf_tcp": {
+      "mask": "0x20",
+      "tpoint_mask": "0x0"
+    },
+    "blobfs": {
+      "mask": "0x80",
+      "tpoint_mask": "0x0"
+    },
+    "thread": {
+      "mask": "0x400",
+      "tpoint_mask": "0x0"
+    },
+    "nvme_pcie": {
+      "mask": "0x800",
+      "tpoint_mask": "0x0"
+    },
+    "nvme_tcp": {
+      "mask": "0x2000",
+      "tpoint_mask": "0x0"
+    },
+    "bdev_nvme": {
+      "mask": "0x4000",
+      "tpoint_mask": "0x0"
+    }
+  }
+}
+~~~
+
 ### log_set_print_level {#rpc_log_set_print_level}
 
 Set the current level at which output will additionally be

lib/trace/Makefile

@@ -7,7 +7,7 @@ SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
 SO_VER := 7
-SO_MINOR := 0
+SO_MINOR := 1
 
 C_SRCS = trace.c trace_flags.c trace_rpc.c
 LIBNAME = trace

lib/trace/trace.c

@@ -13,6 +13,7 @@
 #include "spdk/log.h"
 #include "spdk/cpuset.h"
 #include "spdk/likely.h"
+#include "trace_internal.h"
 
 static int g_trace_fd = -1;
 static char g_shm_name[64];
@@ -271,3 +272,9 @@ spdk_trace_cleanup(void)
 		shm_unlink(g_shm_name);
 	}
 }
+
+const char *
+trace_get_shm_name(void)
+{
+	return g_shm_name;
+}

lib/trace/trace_internal.h

@@ -0,0 +1,14 @@
+/*   SPDX-License-Identifier: BSD-3-Clause
+ *   Copyright (C) 2022 Intel Corporation.
+ *   All rights reserved.
+ */
+
+#ifndef __TRACE_INTERNAL_H__
+#define __TRACE_INTERNAL_H__
+
+#include "spdk/trace.h"
+
+/* Get shared memory file name. */
+const char *trace_get_shm_name(void);
+
+#endif

lib/trace/trace_rpc.c

@@ -7,6 +7,7 @@
 #include "spdk/util.h"
 #include "spdk/trace.h"
 #include "spdk/log.h"
+#include "trace_internal.h"
 
 struct rpc_tpoint_group {
 	char *name;
@@ -211,3 +212,52 @@ rpc_trace_get_tpoint_group_mask(struct spdk_jsonrpc_request *request,
 }
 SPDK_RPC_REGISTER("trace_get_tpoint_group_mask", rpc_trace_get_tpoint_group_mask,
 		  SPDK_RPC_STARTUP | SPDK_RPC_RUNTIME)
+
+static void
+rpc_trace_get_info(struct spdk_jsonrpc_request *request,
+		   const struct spdk_json_val *params)
+{
+	char shm_path[128];
+	uint64_t tpoint_group_mask;
+	uint64_t tpoint_mask;
+	char tpoint_mask_str[20];
+	char mask_str[20];
+	struct spdk_json_write_ctx *w;
+	struct spdk_trace_register_fn *register_fn;
+
+	if (params != NULL) {
+		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
+						 "trace_get_info requires no parameters");
+		return;
+	}
+
+	snprintf(shm_path, sizeof(shm_path), "/dev/shm%s", trace_get_shm_name());
+	tpoint_group_mask = spdk_trace_get_tpoint_group_mask();
+
+	w = spdk_jsonrpc_begin_result(request);
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "tpoint_shm_path", shm_path);
+
+	snprintf(mask_str, sizeof(mask_str), "0x%" PRIx64, tpoint_group_mask);
+	spdk_json_write_named_string(w, "tpoint_group_mask", mask_str);
+
+	register_fn = spdk_trace_get_first_register_fn();
+	while (register_fn) {
+
+		tpoint_mask = spdk_trace_get_tpoint_mask(register_fn->tgroup_id);
+
+		spdk_json_write_named_object_begin(w, register_fn->name);
+		snprintf(mask_str, sizeof(mask_str), "0x%lx", (1UL << register_fn->tgroup_id));
+		spdk_json_write_named_string(w, "mask", mask_str);
+		snprintf(tpoint_mask_str, sizeof(tpoint_mask_str), "0x%lx", tpoint_mask);
+		spdk_json_write_named_string(w, "tpoint_mask", tpoint_mask_str);
+		spdk_json_write_object_end(w);
+
+		register_fn = spdk_trace_get_next_register_fn(register_fn);
+	}
+
+	spdk_json_write_object_end(w);
+	spdk_jsonrpc_end_result(request, w);
+}
+SPDK_RPC_REGISTER("trace_get_info", rpc_trace_get_info,
+		  SPDK_RPC_STARTUP | SPDK_RPC_RUNTIME)

python/spdk/rpc/trace.py

@@ -53,3 +53,12 @@ def trace_get_tpoint_group_mask(client):
         List of trace point group mask
     """
     return client.call('trace_get_tpoint_group_mask')
+
+
+def trace_get_info(client):
+    """Get name of shared memory file and list of the available trace point groups
+
+    Returns:
+        Name of shared memory file and list of the available trace point groups
+    """
+    return client.call('trace_get_info')

scripts/rpc.py

@@ -1803,6 +1803,13 @@ Format: 'user:u1 secret:s1 muser:mu1 msecret:ms1,user:u2 secret:s2 muser:mu2 mse
     p = subparsers.add_parser('trace_get_tpoint_group_mask', help='get trace point group mask')
     p.set_defaults(func=trace_get_tpoint_group_mask)
 
+    def trace_get_info(args):
+        print_dict(rpc.trace.trace_get_info(args.client))
+
+    p = subparsers.add_parser('trace_get_info',
+                              help='get name of shared memory file and list of the available trace point groups')
+    p.set_defaults(func=trace_get_info)
+
     # log
     def log_set_flag(args):
         rpc.log.log_set_flag(args.client, flag=args.flag)

test/rpc/rpc.sh

@@ -40,7 +40,18 @@ function rpc_plugins() {
 	}
 }
 
-$SPDK_BIN_DIR/spdk_tgt &
+function rpc_trace_cmd_test() {
+	local info
+
+	info=$($rpc trace_get_info)
+	[ "$(jq length <<< "$info")" -gt 2 ]
+	[ "$(jq 'has("tpoint_group_mask")' <<< "$info")" = "true" ]
+	[ "$(jq 'has("tpoint_shm_path")' <<< "$info")" = "true" ]
+	[ "$(jq 'has("bdev")' <<< "$info")" = "true" ]
+	[ "$(jq -r .bdev.tpoint_mask <<< "$info")" != "0x0" ]
+}
+
+$SPDK_BIN_DIR/spdk_tgt -e bdev &
 spdk_pid=$!
 trap 'killprocess $spdk_pid; exit 1' SIGINT SIGTERM EXIT
 waitforlisten $spdk_pid
@@ -51,6 +62,7 @@ export PYTHONPATH=$PYTHONPATH:$testdir
 rpc=rpc_cmd
 run_test "rpc_integrity" rpc_integrity
 run_test "rpc_plugins" rpc_plugins
+run_test "rpc_trace_cmd_test" rpc_trace_cmd_test
 # same integrity test, but with rpc_cmd() instead
 rpc="rpc_cmd"
 run_test "rpc_daemon_integrity" rpc_integrity