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From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v26 04/15] trace-cmd: Add clock parameter to timestamp synchronization plugins
Date: Thu, 21 Jan 2021 09:44:45 +0200
Message-ID: <20210121074456.157658-5-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20210121074456.157658-1-tz.stoyanov@gmail.com>

Some timestamp synchronization plugins may not support all ftrace
clocks. Added logic to timestamp synchronization plugins to declare what
ftrace clocks they support. Added logic to select plugin depending on the
ftrace clock used in the current trace session and supported clocks.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  4 +--
 lib/trace-cmd/include/trace-tsync-local.h     |  1 +
 lib/trace-cmd/trace-timesync.c                | 30 +++++++++++++++----
 tracecmd/trace-record.c                       | 10 ++++++-
 tracecmd/trace-tsync.c                        |  2 +-
 5 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 0d323947..ff700e44 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -430,8 +430,8 @@ struct tracecmd_time_sync {
 };
 
 void tracecmd_tsync_init(void);
-int tracecmd_tsync_proto_getall(struct tracecmd_tsync_protos **protos);
-const char *tracecmd_tsync_proto_select(struct tracecmd_tsync_protos *protos);
+int tracecmd_tsync_proto_getall(struct tracecmd_tsync_protos **protos, const char *clock);
+const char *tracecmd_tsync_proto_select(struct tracecmd_tsync_protos *protos, char *clock);
 bool tsync_proto_is_supported(const char *proto_name);
 void tracecmd_tsync_with_host(struct tracecmd_time_sync *tsync);
 void tracecmd_tsync_with_guest(struct tracecmd_time_sync *tsync);
diff --git a/lib/trace-cmd/include/trace-tsync-local.h b/lib/trace-cmd/include/trace-tsync-local.h
index 58841a4c..96ec89e9 100644
--- a/lib/trace-cmd/include/trace-tsync-local.h
+++ b/lib/trace-cmd/include/trace-tsync-local.h
@@ -27,6 +27,7 @@ struct clock_sync_context {
 };
 
 int tracecmd_tsync_proto_register(const char *proto_name, int accuracy,
+				  int supported_clocks,
 				  int (*init)(struct tracecmd_time_sync *),
 				  int (*free)(struct tracecmd_time_sync *),
 				  int (*calc)(struct tracecmd_time_sync *,
diff --git a/lib/trace-cmd/trace-timesync.c b/lib/trace-cmd/trace-timesync.c
index c9fde0fa..0d46d294 100644
--- a/lib/trace-cmd/trace-timesync.c
+++ b/lib/trace-cmd/trace-timesync.c
@@ -26,6 +26,7 @@ struct tsync_proto {
 	struct tsync_proto *next;
 	char proto_name[TRACECMD_TSYNC_PNAME_LENGTH];
 	int accuracy;
+	int supported_clocks;
 
 	int (*clock_sync_init)(struct tracecmd_time_sync *clock_context);
 	int (*clock_sync_free)(struct tracecmd_time_sync *clock_context);
@@ -50,6 +51,7 @@ static struct tsync_proto *tsync_proto_find(const char *proto_name)
 }
 
 int tracecmd_tsync_proto_register(const char *proto_name, int accuracy,
+				  int supported_clocks,
 				  int (*init)(struct tracecmd_time_sync *),
 				  int (*free)(struct tracecmd_time_sync *),
 				  int (*calc)(struct tracecmd_time_sync *,
@@ -64,6 +66,7 @@ int tracecmd_tsync_proto_register(const char *proto_name, int accuracy,
 		return -1;
 	strncpy(proto->proto_name, proto_name, TRACECMD_TSYNC_PNAME_LENGTH);
 	proto->accuracy = accuracy;
+	proto->supported_clocks = supported_clocks;
 	proto->clock_sync_init = init;
 	proto->clock_sync_free = free;
 	proto->clock_sync_calc = calc;
@@ -137,23 +140,29 @@ int tracecmd_tsync_get_offsets(struct tracecmd_time_sync *tsync,
  *		timestamp synchronization with a peer
  *
  * @protos: list of tsync protocol names
+ * @clock : trace clock
  *
  * Retuns pointer to a protocol name, that can be used with the peer, or NULL
  *	  in case there is no match with supported protocols.
  *	  The returned string MUST NOT be freed by the caller
  */
-const char *tracecmd_tsync_proto_select(struct tracecmd_tsync_protos *protos)
+const char *tracecmd_tsync_proto_select(struct tracecmd_tsync_protos *protos, char *clock)
 {
 	struct tsync_proto *selected = NULL;
 	struct tsync_proto *proto;
 	char **pname;
+	int clock_id = 0;
 
 	if (!protos)
 		return NULL;
 
+	clock_id = tracecmd_clock_str2id(clock);
 	pname = protos->names;
 	while (*pname) {
 		for (proto = tsync_proto_list; proto; proto = proto->next) {
+			if (proto->supported_clocks && clock_id &&
+			    !(proto->supported_clocks & clock_id))
+				continue;
 			if (strncmp(proto->proto_name, *pname, TRACECMD_TSYNC_PNAME_LENGTH))
 				continue;
 			if (selected) {
@@ -176,20 +185,28 @@ const char *tracecmd_tsync_proto_select(struct tracecmd_tsync_protos *protos)
  *				 time sync protocols
  * @protos: return, allocated list of time sync protocol names,
  *	       supported by the peer. Must be freed by free()
+ * @clock: selected trace clock
  *
  * If completed successfully 0 is returned and allocated list of strings in @protos.
  * The last list entry is NULL. In case of an error, -1 is returned.
  * @protos must be freed with free()
  */
-int tracecmd_tsync_proto_getall(struct tracecmd_tsync_protos **protos)
+int tracecmd_tsync_proto_getall(struct tracecmd_tsync_protos **protos, const char *clock)
 {
 	struct tracecmd_tsync_protos *plist = NULL;
 	struct tsync_proto *proto;
+	int clock_id = 0;
 	int count = 1;
 	int i;
 
-	for (proto = tsync_proto_list; proto; proto = proto->next)
+	if (clock)
+		clock_id =  tracecmd_clock_str2id(clock);
+	for (proto = tsync_proto_list; proto; proto = proto->next) {
+		if (proto->supported_clocks && clock_id &&
+		    !(proto->supported_clocks & clock_id))
+			continue;
 		count++;
+	}
 	plist = calloc(1, sizeof(struct tracecmd_tsync_protos));
 	if (!plist)
 		goto error;
@@ -197,9 +214,12 @@ int tracecmd_tsync_proto_getall(struct tracecmd_tsync_protos **protos)
 	if (!plist->names)
 		return -1;
 
-	for (i = 0, proto = tsync_proto_list; proto && i < (count - 1); proto = proto->next)
+	for (i = 0, proto = tsync_proto_list; proto && i < (count - 1); proto = proto->next) {
+		if (proto->supported_clocks && clock_id &&
+		    !(proto->supported_clocks & clock_id))
+			continue;
 		plist->names[i++] = proto->proto_name;
-
+	}
 	*protos = plist;
 	return 0;
 
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index a0e128d6..51b8562b 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -3675,8 +3675,11 @@ static void connect_to_agent(struct buffer_instance *instance)
 	if (!msg_handle)
 		die("Failed to allocate message handle");
 
+	if (!instance->clock)
+		instance->clock = tracefs_get_clock(NULL);
+
 	if (instance->tsync.loop_interval >= 0)
-		tracecmd_tsync_proto_getall(&protos);
+		tracecmd_tsync_proto_getall(&protos, instance->clock);
 
 	ret = tracecmd_msg_send_trace_req(msg_handle, instance->argc,
 					  instance->argv, use_fifos,
@@ -6098,6 +6101,11 @@ static void parse_record_options(int argc,
 						 (char *)top_instance.clock,
 						 true);
 					add_argv(instance, "-C", true);
+					if (!instance->clock) {
+						instance->clock = strdup((char *)top_instance.clock);
+						if (!instance->clock)
+							die("Could not allocate instance clock");
+					}
 				}
 			}
 			instance->tsync.loop_interval = top_instance.tsync.loop_interval;
diff --git a/tracecmd/trace-tsync.c b/tracecmd/trace-tsync.c
index 5781cfd2..55e9857f 100644
--- a/tracecmd/trace-tsync.c
+++ b/tracecmd/trace-tsync.c
@@ -223,7 +223,7 @@ const char *tracecmd_guest_tsync(struct tracecmd_tsync_protos *tsync_protos,
 	int fd;
 
 	fd = -1;
-	proto = tracecmd_tsync_proto_select(tsync_protos);
+	proto = tracecmd_tsync_proto_select(tsync_protos, clock);
 	if (!proto)
 		return NULL;
 #ifdef VSOCK
-- 
2.29.2


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-21  7:44 [PATCH v26 00/15] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 01/15] trace-cmd: Replace time sync protocol ID with string Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 02/15] trace-cmd: Add trace-cmd library APIs for ftrace clock name Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 03/15] trace-cmd: Move VM related logic in a separate file Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` Tzvetomir Stoyanov (VMware) [this message]
2021-01-21  7:44 ` [PATCH v26 05/15] trace-cmd: Add role parameter to timestamp synchronization plugins Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 06/15] trace-cmd: Add host / guest role in timestamp synchronization context Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 07/15] trace-cmd: Add guest CPU count PID in tracecmd_time_sync struct Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 08/15] trace-cmd: Add scaling ratio for timestamp correction Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 09/15] trace-cmd: Add time sync protocol flags Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 10/15] trace-cmd: Add timestamp synchronization per vCPU Tzvetomir Stoyanov (VMware)
2021-01-28  2:09   ` Steven Rostedt
2021-01-21  7:44 ` [PATCH v26 11/15] trace-cmd: Define a macro for packed structures Tzvetomir Stoyanov (VMware)
2021-01-28 22:44   ` Steven Rostedt
2021-01-21  7:44 ` [PATCH v26 12/15] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 13/15] trace-cmd: [POC] PTP-like algorithm for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 14/15] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
2021-01-21  7:44 ` [PATCH v26 15/15] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)

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