Red Hat Bugzilla – Bug 840326
KVM guest: sched_clock() broken across migration with differing TSC frequency
Last modified: 2012-07-22 14:44:46 EDT
sched_clock() should not be using TSC as its not virtualized
but passthrough, meaning that migration can change TSC frequency.
unsigned long long sched_clock(void)
unsigned long a = 0;
RHEL6 KVM guests and RHEL5 XEN guests correctly use pvclock to return
time to sched_clock, but RHEL5 i386/x86_64 KVM guests are broken.