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author | Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | 2011-03-16 19:05:58 -0400 |
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committer | Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | 2011-03-16 19:05:58 -0400 |
commit | 710944c4e1f7468dba1a0c4fa36b4cda5846f350 (patch) | |
tree | 76200076cc8da29802f888364a812a473ac9406e /arch/x86/kernel | |
parent | d58cc7d529b3944617b1e4453f747b5cdec011c7 (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.c | 2 |
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) |