X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lttng-events.c;h=a3758229c745ef53fa0929d766fc95dce8d66bec;hb=ba21566bd4d49e97184ac34bec82a95f47da28b4;hp=0ef87a8c992a9224b613b218ac1e324b95440a43;hpb=a90917c3f8c4ed79117f1caa333b29a2108084ec;p=lttng-modules.git

diff --git a/lttng-events.c b/lttng-events.c
index 0ef87a8c..a3758229 100644
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -14,8 +14,10 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
+#include <linux/utsname.h>
 #include "wrapper/uuid.h"
 #include "wrapper/vmalloc.h"	/* for wrapper_vmalloc_sync_all() */
+#include "wrapper/random.h"
 #include "lttng-events.h"
 #include "lttng-tracer.h"
 
@@ -111,6 +113,11 @@ int lttng_session_enable(struct lttng_session *session)
 	ACCESS_ONCE(session->active) = 1;
 	ACCESS_ONCE(session->been_active) = 1;
 	ret = _lttng_session_metadata_statedump(session);
+	if (ret) {
+		ACCESS_ONCE(session->active) = 0;
+		goto end;
+	}
+	ret = lttng_statedump_start(session);
 	if (ret)
 		ACCESS_ONCE(session->active) = 0;
 end:
@@ -794,8 +801,8 @@ int _lttng_stream_packet_context_declare(struct lttng_session *session)
 {
 	return lttng_metadata_printf(session,
 		"struct packet_context {\n"
-		"	uint64_t timestamp_begin;\n"
-		"	uint64_t timestamp_end;\n"
+		"	uint64_clock_monotonic_t timestamp_begin;\n"
+		"	uint64_clock_monotonic_t timestamp_end;\n"
 		"	uint32_t events_discarded;\n"
 		"	uint32_t content_size;\n"
 		"	uint32_t packet_size;\n"
@@ -821,11 +828,11 @@ int _lttng_event_header_declare(struct lttng_session *session)
 	"	enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
 	"	variant <id> {\n"
 	"		struct {\n"
-	"			uint27_t timestamp;\n"
+	"			uint27_clock_monotonic_t timestamp;\n"
 	"		} compact;\n"
 	"		struct {\n"
 	"			uint32_t id;\n"
-	"			uint64_t timestamp;\n"
+	"			uint64_clock_monotonic_t timestamp;\n"
 	"		} extended;\n"
 	"	} v;\n"
 	"} align(%u);\n"
@@ -834,11 +841,11 @@ int _lttng_event_header_declare(struct lttng_session *session)
 	"	enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
 	"	variant <id> {\n"
 	"		struct {\n"
-	"			uint32_t timestamp;\n"
+	"			uint32_clock_monotonic_t timestamp;\n"
 	"		} compact;\n"
 	"		struct {\n"
 	"			uint32_t id;\n"
-	"			uint64_t timestamp;\n"
+	"			uint64_clock_monotonic_t timestamp;\n"
 	"		} extended;\n"
 	"	} v;\n"
 	"} align(%u);\n\n",
@@ -847,6 +854,33 @@ int _lttng_event_header_declare(struct lttng_session *session)
 	);
 }
 
+ /*
+ * Approximation of NTP time of day to clock monotonic correlation,
+ * taken at start of trace.
+ * Yes, this is only an approximation. Yes, we can (and will) do better
+ * in future versions.
+ */
+static
+uint64_t measure_clock_offset(void)
+{
+	uint64_t offset, monotonic[2], realtime;
+	struct timespec rts = { 0, 0 };
+	unsigned long flags;
+
+	/* Disable interrupts to increase correlation precision. */
+	local_irq_save(flags);
+	monotonic[0] = trace_clock_read64();
+	getnstimeofday(&rts);      
+	monotonic[1] = trace_clock_read64();
+	local_irq_restore(flags);
+
+	offset = (monotonic[0] + monotonic[1]) >> 1;
+	realtime = rts.tv_sec * NSEC_PER_SEC;
+	realtime += rts.tv_nsec;
+	offset = realtime - offset;
+	return offset;
+}
+
 /*
  * Output metadata into this session's metadata buffers.
  */
@@ -854,7 +888,7 @@ static
 int _lttng_session_metadata_statedump(struct lttng_session *session)
 {
 	unsigned char *uuid_c = session->uuid.b;
-	unsigned char uuid_s[37];
+	unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
 	struct lttng_channel *chan;
 	struct lttng_event *event;
 	int ret = 0;
@@ -910,6 +944,71 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
 	if (ret)
 		goto end;
 
+	ret = lttng_metadata_printf(session,
+		"env {\n"
+		"	domain = \"%s\";\n"
+		"	sysname = \"%s\";\n"
+		"	release = \"%s\";\n"
+		"	version = \"%s\";\n"
+		"};\n\n",
+		"kernel",
+		utsname()->sysname,
+		utsname()->release,
+		utsname()->version
+		);
+	if (ret)
+		goto end;
+
+	ret = lttng_metadata_printf(session,
+		"clock {\n"
+		"	name = %s;\n",
+		"monotonic"
+		);
+	if (ret)
+		goto end;
+
+	if (!trace_clock_uuid(clock_uuid_s)) {
+		ret = lttng_metadata_printf(session,
+			"	uuid = \"%s\";\n",
+			clock_uuid_s
+			);
+		if (ret)
+			goto end;
+	}
+
+	ret = lttng_metadata_printf(session,
+		"	description = \"Monotonic Clock\";\n"
+		"	freq = %llu; /* Frequency, in Hz */\n"
+		"	/* clock value offset from Epoch is: offset * (1/freq) */\n"
+		"	offset = %llu;\n"
+		"};\n\n",
+		(unsigned long long) trace_clock_freq(),
+		(unsigned long long) measure_clock_offset()
+		);
+	if (ret)
+		goto end;
+
+	ret = lttng_metadata_printf(session,
+		"typealias integer {\n"
+		"	size = 27; align = 1; signed = false;\n"
+		"	map = clock.monotonic.value;\n"
+		"} := uint27_clock_monotonic_t;\n"
+		"\n"
+		"typealias integer {\n"
+		"	size = 32; align = %u; signed = false;\n"
+		"	map = clock.monotonic.value;\n"
+		"} := uint32_clock_monotonic_t;\n"
+		"\n"
+		"typealias integer {\n"
+		"	size = 64; align = %u; signed = false;\n"
+		"	map = clock.monotonic.value;\n"
+		"} := uint64_clock_monotonic_t;\n\n",
+		lttng_alignof(uint32_t) * CHAR_BIT,
+		lttng_alignof(uint64_t) * CHAR_BIT
+		);
+	if (ret)
+		goto end;
+
 	ret = _lttng_stream_packet_context_declare(session);
 	if (ret)
 		goto end;