During TSC synchronization test, use rdtsc() rather than rdtsc32(), to

protect against 32-bit TSC overflow while the sync test is running.

On dual-socket Xeon E5-2600 (SNB) systems with up to 32 threads, there
is non-trivial chance (2-3%) that TSC synchronization test fails due to
32-bit TSC overflow while the synchronization test is running.

Sponsored by: Intel
Reviewed by: jkim
Discussed with: jkim, kib

1 files changed, 5 insertions, 5 deletions

diff --git a/sys/x86/x86/tsc.c b/sys/x86/x86/tsc.c
index 94bd520..04231b8 100644
--- a/sys/x86/x86/tsc.c
+++ b/sys/x86/x86/tsc.c
@@ -363,11 +363,11 @@ init_TSC(void)
 static void								\
 tsc_read_##x(void *arg)							\
 {									\
-	uint32_t *tsc = arg;						\
+	uint64_t *tsc = arg;						\
 	u_int cpu = PCPU_GET(cpuid);					\
 									\
 	__asm __volatile("cpuid" : : : "eax", "ebx", "ecx", "edx");	\
-	tsc[cpu * 3 + x] = rdtsc32();					\
+	tsc[cpu * 3 + x] = rdtsc();					\
 }
 TSC_READ(0)
 TSC_READ(1)
@@ -379,8 +379,8 @@ TSC_READ(2)
 static void
 comp_smp_tsc(void *arg)
 {
-	uint32_t *tsc;
-	int32_t d1, d2;
+	uint64_t *tsc;
+	int64_t d1, d2;
 	u_int cpu = PCPU_GET(cpuid);
 	u_int i, j, size;
 
@@ -401,7 +401,7 @@ comp_smp_tsc(void *arg)
 static int
 test_smp_tsc(void)
 {
-	uint32_t *data, *tsc;
+	uint64_t *data, *tsc;
 	u_int i, size;
 
 	if (!smp_tsc && !tsc_is_invariant)