From: Nikita Andreev (nik_at_kemsu.ru)
Date: Mon Mar 22 2010 - 23:55:09 PDT
Hello Paul and all,
I'm measuring the overhead of bupc_ticks_now() and bupc_ticks_to_ns() and
results doesn't look like I expected. Find the test attached.
I've made 1 million iterations and have got the following:
bupc_ticks_now: 2383ns
bupc_ticks_to_ns: 4ns
So the conversion is made lot faster than query. But documentation says: The
bupc_ticks_to_{us,ns}() conversion calls can be significantly more expensive
than the bupc_ticks_now() tick query.
What I also noticed is that first bupc_tick_to_ns call in a loop is very
slow. It can take even 1,5 milliseconds. And almost all others are very
fast.
What am I missing here?
P.S. I've performed this test on a virtual machine if it makes any
difference.
Regards,
Nikita Andreev