[ltt-dev] [PATCH] We now rely on the lib userspace rcu API for the trace_clock_read64 function that will now use get_cycles which is architecture _aware_

[David Goulet]

---
 include/ust/clock.h |   72 +++++----------------------------------------------
 1 files changed, 7 insertions(+), 65 deletions(-)

diff --git a/include/ust/clock.h b/include/ust/clock.h
index cb8a663..27279b6 100644
--- a/include/ust/clock.h
+++ b/include/ust/clock.h
@@ -18,8 +18,6 @@
 #ifndef UST_CLOCK_H
 #define UST_CLOCK_H
 
-#include <time.h>
-#include <sys/time.h>
 #include <ust/kcompat/kcompat.h>
 
 /* TRACE CLOCK */
@@ -35,77 +33,21 @@
    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.
-
+   We now use the lib userspace RCU API for clock read.
 */
 
-#define TRACE_CLOCK_GENERIC
-#ifdef TRACE_CLOCK_GENERIC
-
-static __inline__ u64 trace_clock_read64(void)
-{
-	struct timespec ts;
-	u64 retval;
-
-	clock_gettime(CLOCK_MONOTONIC, &ts);
-	retval = ts.tv_sec;
-	retval *= 1000000000;
-	retval += ts.tv_nsec;
-
-	return retval;
-}
-
-#else
-
-#if __i386 || __x86_64
-
-/* WARNING: Make sure to set frequency and scaling functions that will not
- * result in lttv timestamps (sec.nsec) with seconds greater than 2**32-1.
+/*
+ * Generic trace_clock_read64 function
  */
 static __inline__ u64 trace_clock_read64(void)
 {
-	uint32_t low;
-	uint32_t high;
-	uint64_t retval;
-	__asm__ volatile ("rdtsc\n" : "=a" (low), "=d" (high));
+	cycles_t retval;
 
-	retval = high;
-	retval <<= 32;
-	return retval | low;
+	/* Lib urcu API for cycles count */
+	retval = get_cycles();
+	return (u64)retval;
 }
 
-#endif /* __i386 || __x86_64 */
-
-#ifdef __PPC__
-
-static __inline__ u64 trace_clock_read64(void)
-{
-	unsigned long tb_l;
-	unsigned long tb_h;
-	unsigned long tb_h2;
-	u64 tb;
-
-	__asm__ (
-		"1:\n\t"
-		"mftbu %[rhigh]\n\t"
-		"mftb %[rlow]\n\t"
-		"mftbu %[rhigh2]\n\t"
-		"cmpw %[rhigh],%[rhigh2]\n\t"
-		"bne 1b\n\t"
-	: [rhigh] "=r" (tb_h), [rhigh2] "=r" (tb_h2), [rlow] "=r" (tb_l));
-	
-	tb = tb_h;
-	tb <<= 32;
-	tb |= tb_l;
-
-	return tb;
-}
-
-#endif /* __PPC__ */
-
-#endif /* ! UST_TRACE_CLOCK_GENERIC */
-
 static __inline__ u64 trace_clock_frequency(void)
 {
 	return 1000000000LL;
-- 
1.7.0.4