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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2011-03-16 19:05:58 -0400
committerMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2011-03-16 19:05:58 -0400
commit710944c4e1f7468dba1a0c4fa36b4cda5846f350 (patch)
tree76200076cc8da29802f888364a812a473ac9406e /arch/x86/kernel
parentd58cc7d529b3944617b1e4453f747b5cdec011c7 (diff)
trace-clock-remove-extra-barriers-on-x86
trace clock remove extra barriers on x86 Given that a tracer cannot realistically provide accuracy better than the inaccuracy between the traced action (e.g. an atomic operation) and the timestamp read, having barriers around the timestamp read is just overkill. This will speed up tracing. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/trace-clock.c2
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/kernel/trace-clock.c b/arch/x86/kernel/trace-clock.c
index ec866aa9591..37cf125a940 100644
--- a/arch/x86/kernel/trace-clock.c
+++ b/arch/x86/kernel/trace-clock.c
@@ -69,9 +69,7 @@ notrace cycles_t trace_clock_async_tsc_read(void)
cycles_t new_tsc, last_tsc;
WARN_ON(!async_tsc_refcount || !async_tsc_enabled);
- rdtsc_barrier();
new_tsc = get_cycles();
- rdtsc_barrier();
last_tsc = read_last_tsc();
do {
if (new_tsc < last_tsc)