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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 v18 14/18] trace-cmd: Add host trace clock as guest trace argument
Date: Fri, 13 Dec 2019 17:30:25 +0200
Message-ID: <20191213153029.133570-15-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20191213153029.133570-1-tz.stoyanov@gmail.com>

When tracing host and guest machines, both should use the same
tracing clock for event timestamps. If a clock is specified
as host tracing argument, with option "-C clock_name", the same
is injected as guest tracing argument. If the user wants to use
different tracing clocks, it can specify it using "-C clock_name"
as guest tracing argument. In that case, the one specified by
the user has higher priority.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 tracecmd/include/trace-local.h |  1 +
 tracecmd/trace-record.c        | 24 ++++++++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 90933cc..4c8d6cb 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -165,6 +165,7 @@ enum buffer_instance_flags {
 	BUFFER_FL_PROFILE	= 1 << 1,
 	BUFFER_FL_GUEST		= 1 << 2,
 	BUFFER_FL_AGENT		= 1 << 3,
+	BUFFER_FL_HAS_CLOCK	= 1 << 4,
 };
 
 struct func_list {
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index e4e2d63..51b40ff 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -5405,6 +5405,8 @@ static void parse_record_options(int argc,
 	char *sav;
 	int name_counter = 0;
 	int neg_event = 0;
+	struct buffer_instance *instance;
+	bool guest_sync_set = false;
 
 	init_common_record_context(ctx, curr_cmd);
 
@@ -5448,6 +5450,8 @@ static void parse_record_options(int argc,
 		 */
 		if (c != 'B' && c != 'A' && is_guest(ctx->instance)) {
 			add_arg(ctx->instance, c, opts, long_options, optarg);
+			if (c == 'C')
+				ctx->instance->flags |= BUFFER_FL_HAS_CLOCK;
 			continue;
 		}
 
@@ -5562,6 +5566,9 @@ static void parse_record_options(int argc,
 			break;
 		case 'C':
 			tracecmd_alloc_instance_clock(ctx->instance->ftrace, optarg);
+			ctx->instance->flags |= BUFFER_FL_HAS_CLOCK;
+			if (is_top_instance(ctx->instance))
+				guest_sync_set = true;
 			break;
 		case 'v':
 			neg_event = 1;
@@ -5779,14 +5786,27 @@ static void parse_record_options(int argc,
 
 	/* If --date is specified, prepend it to all guest VM flags */
 	if (ctx->date) {
-		struct buffer_instance *instance;
-
 		for_all_instances(instance) {
 			if (is_guest(instance))
 				add_argv(instance, "--date", true);
 		}
 	}
 
+	if (guest_sync_set) {
+		/* If -C is specified, prepend clock to all guest VM flags */
+		for_all_instances(instance) {
+			if (tracecmd_get_instance_clock(top_instance.ftrace)) {
+				if (is_guest(instance) &&
+				    !(instance->flags & BUFFER_FL_HAS_CLOCK)) {
+					add_argv(instance,
+						 tracecmd_get_instance_clock(top_instance.ftrace),
+						 true);
+					add_argv(instance, "-C", true);
+				}
+			}
+		}
+	}
+
 	if (!ctx->filtered && ctx->instance->filter_mod)
 		add_func(&ctx->instance->filter_funcs,
 			 ctx->instance->filter_mod, "*");
-- 
2.23.0


  parent reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-13 15:30 [PATCH v18 00/18]Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 01/18] trace-cmd: Implement new lib API: tracecmd_local_events_system() Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 02/18] trace-cmd: Add support for negative time offsets in trace.dat file Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 03/18] trace-cmd: Add implementations of htonll() and ntohll() Tzvetomir Stoyanov (VMware)
2019-12-21  2:34   ` Steven Rostedt
2019-12-13 15:30 ` [PATCH v18 04/18] trace-cmd: Add new library APIs for ftrace instances Tzvetomir Stoyanov (VMware)
2019-12-21  3:03   ` Steven Rostedt
2020-01-06 14:47     ` Tzvetomir Stoyanov
2019-12-13 15:30 ` [PATCH v18 05/18] trace-cmd: Add new library API for local CPU count Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 06/18] trace-cmd: Add new library API for reading ftrace buffers Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 07/18] trace-cmd: Find and store pids of tasks, which run virtual CPUs of given VM Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 08/18] trace-cmd: Implement new API tracecmd_add_option_v() Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 09/18] trace-cmd: Add new API to generate a unique ID of the tracing session Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 10/18] trace-cmd: Store the session tracing ID in the trace.dat file Tzvetomir Stoyanov (VMware)
2019-12-20 20:04   ` Steven Rostedt
2020-01-06 14:33     ` Tzvetomir Stoyanov
2019-12-13 15:30 ` [PATCH v18 11/18] trace-cmd: Exchange tracing IDs between host and guest Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 12/18] trace-cmd: Implement new option in trace.dat file: TRACECMD_OPTION_TIME_SHIFT Tzvetomir Stoyanov (VMware)
2019-12-21  3:19   ` Steven Rostedt
2019-12-13 15:30 ` [PATCH v18 13/18] trace-cmd: Add guest information in host's trace.dat file Tzvetomir Stoyanov (VMware)
2019-12-20 20:52   ` Steven Rostedt
2020-01-06 14:43     ` Tzvetomir Stoyanov
2020-01-06 14:55       ` Steven Rostedt
2019-12-13 15:30 ` Tzvetomir Stoyanov (VMware) [this message]
2019-12-13 15:30 ` [PATCH v18 15/18] trace-cmd: Refactor few trace-cmd internal functions Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 16/18] trace-cmd: Basic infrastructure for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
2019-12-21  4:48   ` Steven Rostedt
2020-01-31  9:53     ` Tzvetomir Stoyanov
2020-01-31 14:49       ` Steven Rostedt
2019-12-13 15:30 ` [PATCH v18 17/18] trace-cmd: [POC] PTP-like algorithm " Tzvetomir Stoyanov (VMware)
2019-12-13 15:30 ` [PATCH v18 18/18] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)

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