X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=include%2Fust%2Fclock.h;h=ae44becae58f8bbbd9521e1df54bc7867d1992ab;hb=d4419b81b243bc3a6bdd4a09b3ca2216d044a1c7;hp=5e8f755b9c08573d1fd7ec110156fe3ea71bdaf4;hpb=9edd34bd25f52dd39b354a84f02697254121aefd;p=lttng-ust.git

diff --git a/include/ust/clock.h b/include/ust/clock.h
index 5e8f755b..ae44beca 100644
--- a/include/ust/clock.h
+++ b/include/ust/clock.h
@@ -1,9 +1,11 @@
-/* Copyright (C) 2010  Pierre-Marc Fournier
+/*
+ * Copyright (C) 2010  Pierre-Marc Fournier
+ * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * License as published by the Free Software Foundation; version 2.1 of
+ * the License.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -26,30 +28,10 @@
 
 /* TRACE CLOCK */
 
-/* There are two types of clocks that can be used.
-   - TSC based clock
-   - gettimeofday() clock
-
-   Microbenchmarks on Linux 2.6.30 on Core2 Duo 3GHz (functions are inlined):
-	 Calls (100000000) to tsc(): 4004035641 cycles or 40 cycles/call
-	 Calls (100000000) to gettimeofday(): 9723158352 cycles or 97 cycles/call
-
-   For merging traces with the kernel, a time source compatible with that of
-   the kernel is necessary.
-
-   Instead of gettimeofday(), we are now using clock_gettime for better
-   precision and monotonicity.
-*/
-
-/* Only available for x86 arch */
-#define CLOCK_TRACE_FREQ  14
-#define CLOCK_TRACE  15
-union lttng_timespec {
-	struct timespec ts;
-	uint64_t lttng_ts;
-};
-
-extern int ust_clock_source;
+/*
+ * Currently using the kernel MONOTONIC clock, waiting for kernel-side
+ * LTTng to implement mmap'd trace clock.
+ */
 
 /* Choosing correct trace clock */
 
@@ -57,39 +39,17 @@ static __inline__ uint64_t trace_clock_read64(void)
 {
 	struct timespec ts;
 	uint64_t retval;
-	union lttng_timespec *lts = (union lttng_timespec *) &ts;
 
-	clock_gettime(ust_clock_source, &ts);
-	/*
-	 * Clock source can change when loading the binary (tracectl.c)
-	 * so we must check if the clock source has changed before
-	 * returning the correct value
-	 */
-	if (likely(ust_clock_source == CLOCK_TRACE)) {
-		retval = lts->lttng_ts;
-	} else { /* CLOCK_MONOTONIC */
-		retval = ts.tv_sec;
-		retval *= 1000000000;
-		retval += ts.tv_nsec;
-	}
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	retval = ts.tv_sec;
+	retval *= 1000000000;
+	retval += ts.tv_nsec;
 
 	return retval;
 }
 
 #if __i386__ || __x86_64__
 static __inline__ uint64_t trace_clock_frequency(void)
-{
-	struct timespec ts;
-	union lttng_timespec *lts = (union lttng_timespec *) &ts;
-
-	if (likely(ust_clock_source == CLOCK_TRACE)) {
-		clock_gettime(CLOCK_TRACE_FREQ, &ts);
-		return lts->lttng_ts;
-	}
-	return 1000000000LL;
-}
-#else /* #if __i386__ || __x86_64__ */
-static __inline__ uint64_t trace_clock_frequency(void)
 {
 	return 1000000000LL;
 }