On 11/17/2009 11:59 AM, Jan Kiszka wrote:
Jan Kiszka wrote:
Dietmar Maurer wrote:
Hi Jan,
The ubuntu code puts some barrier around the read.
http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-hardy.git;a=commitdiff;h=198b348d96c9769153e72ca2461f8d841ddff1cc
You simply override this with your own code - without barrier. Do you think this is correct?
Unless I messed it up again, I "overwrote" it with what is in latest
mainline regarding native_read_tsc. But I will check once more.
The removal of those barriers came with
0d12cdd5f883f508d33b85c1bae98fa28987c8c7 (sched: improve sched_clock()
performance). So this is now an upstream question:
Do we bother about the precision of native_read_tsc in svm or not?
I doubt it matters. rdtsc will be followed by a return to the guest or
userspace, either of which is expensive enough to swamp any speculation.
--
error compiling committee.c: too many arguments to function
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