On Mon, 2012-07-09 at 17:51 +0300, Avi Kivity wrote:On 07/09/2012 05:49 PM, Peter Zijlstra wrote:On Mon, 2012-07-09 at 08:47 -0600, David Ahern wrote:
I found this testing changes to perf-kvm, but found the problem extends
to just perf-record. With perf-record exclude_guest defaults to 1. See
tools/perf/util/util.c, event_attr_init().
You lost me there.. so perf-record defaults to exclude_guest=1 (which
would make the proposed patch I just send actually possible), but its
still going *bang* ?
It's possible that the DS writes overshoot the MSR... or that there's a
bug somewhere.
OK, so the first thing to stare at is in what order the MSRs are
touched, I think you first need to stop the counter, then clear the PEBS
bits, then clear the DS_AREA one.