X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=wrapper%2Ftrace-clock.h;h=d6439c7fb13bb1249560e1351cf649a94056414f;hb=39e088f37e7cb43f35af05b81bf1e23542623802;hp=b145b826571ee4fe3095973a0f6360de3344c9e6;hpb=b07252070edd244987bf160c1ee488d4796bb3a3;p=lttng-modules.git

diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
index b145b826..d6439c7f 100644
--- a/wrapper/trace-clock.h
+++ b/wrapper/trace-clock.h
@@ -36,12 +36,17 @@
 #include <linux/version.h>
 #include <asm/local.h>
 #include "../lttng-kernel-version.h"
+#include "../lttng-clock.h"
+#include "percpu-defs.h"
 #include "random.h"
 
-#if LTTNG_KERNEL_RANGE(3,10,0, 3,10,14) || LTTNG_KERNEL_RANGE(3,11,0, 3,11,3)
+#if ((LTTNG_KERNEL_RANGE(3,10,0, 3,10,14) && !LTTNG_RHEL_KERNEL_RANGE(3,10,0,7,0, 3,10,14,0,0)) \
+	|| LTTNG_KERNEL_RANGE(3,11,0, 3,11,3))
 #error "Linux kernels 3.10 and 3.11 introduce a deadlock in the timekeeping subsystem. Fixed by commit 7bd36014460f793c19e7d6c94dab67b0afcfcb7f \"timekeeping: Fix HRTICK related deadlock from ntp lock changes\" in Linux."
 #endif
 
+extern struct lttng_trace_clock *lttng_trace_clock;
+
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0))
 
 DECLARE_PER_CPU(local_t, lttng_last_tsc);
@@ -88,7 +93,7 @@ static inline u64 trace_clock_fixup(u64 src_now, u64 last)
 #endif /* #else #if (BITS_PER_LONG == 32) */
 
 /*
- * Always called with preemption disabled. Can be interrupted.
+ * Sometimes called with preemption enabled. Can be interrupted.
  */
 static inline u64 trace_clock_monotonic_wrapper(void)
 {
@@ -97,7 +102,8 @@ static inline u64 trace_clock_monotonic_wrapper(void)
 	local_t *last_tsc;
 
 	/* Use fast nmi-safe monotonic clock provided by the Linux kernel. */
-	last_tsc = &__get_cpu_var(lttng_last_tsc);
+	preempt_disable();
+	last_tsc = lttng_this_cpu_ptr(&lttng_last_tsc);
 	last = local_read(last_tsc);
 	/*
 	 * Read "last" before "now". It is not strictly required, but it ensures
@@ -110,6 +116,7 @@ static inline u64 trace_clock_monotonic_wrapper(void)
 	if (((long) now - (long) last) < 0)
 		now = trace_clock_fixup(now, last);
 	result = local_cmpxchg(last_tsc, last, (unsigned long) now);
+	preempt_enable();
 	if (result == last) {
 		/* Update done. */
 		return now;
@@ -140,26 +147,31 @@ static inline u64 trace_clock_monotonic_wrapper(void)
 }
 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)) */
 
-static inline u32 trace_clock_read32(void)
-{
-	return (u32) trace_clock_monotonic_wrapper();
-}
-
-static inline u64 trace_clock_read64(void)
+static inline u64 trace_clock_read64_monotonic(void)
 {
 	return (u64) trace_clock_monotonic_wrapper();
 }
 
-static inline u64 trace_clock_freq(void)
+static inline u64 trace_clock_freq_monotonic(void)
 {
 	return (u64) NSEC_PER_SEC;
 }
 
-static inline int trace_clock_uuid(char *uuid)
+static inline int trace_clock_uuid_monotonic(char *uuid)
 {
 	return wrapper_get_bootid(uuid);
 }
 
+static inline const char *trace_clock_name_monotonic(void)
+{
+	return "monotonic";
+}
+
+static inline const char *trace_clock_description_monotonic(void)
+{
+	return "Monotonic Clock";
+}
+
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0))
 static inline int get_trace_clock(void)
 {
@@ -178,6 +190,67 @@ static inline void put_trace_clock(void)
 {
 }
 
+static inline u64 trace_clock_read64(void)
+{
+	struct lttng_trace_clock *ltc = ACCESS_ONCE(lttng_trace_clock);
+
+	if (likely(!ltc)) {
+		return trace_clock_read64_monotonic();
+	} else {
+		read_barrier_depends();	/* load ltc before content */
+		return ltc->read64();
+	}
+}
+
+static inline u64 trace_clock_freq(void)
+{
+	struct lttng_trace_clock *ltc = ACCESS_ONCE(lttng_trace_clock);
+
+	if (!ltc) {
+		return trace_clock_freq_monotonic();
+	} else {
+		read_barrier_depends();	/* load ltc before content */
+		return ltc->freq();
+	}
+}
+
+static inline int trace_clock_uuid(char *uuid)
+{
+	struct lttng_trace_clock *ltc = ACCESS_ONCE(lttng_trace_clock);
+
+	read_barrier_depends();	/* load ltc before content */
+	/* Use default UUID cb when NULL */
+	if (!ltc || !ltc->uuid) {
+		return trace_clock_uuid_monotonic(uuid);
+	} else {
+		return ltc->uuid(uuid);
+	}
+}
+
+static inline const char *trace_clock_name(void)
+{
+	struct lttng_trace_clock *ltc = ACCESS_ONCE(lttng_trace_clock);
+
+	if (!ltc) {
+		return trace_clock_name_monotonic();
+	} else {
+		read_barrier_depends();	/* load ltc before content */
+		return ltc->name();
+	}
+}
+
+static inline const char *trace_clock_description(void)
+{
+	struct lttng_trace_clock *ltc = ACCESS_ONCE(lttng_trace_clock);
+
+	if (!ltc) {
+		return trace_clock_description_monotonic();
+	} else {
+		read_barrier_depends();	/* load ltc before content */
+		return ltc->description();
+	}
+}
+
 #endif /* CONFIG_HAVE_TRACE_CLOCK */
 
 #endif /* _LTTNG_TRACE_CLOCK_H */