On 13/01/2015 22:14, Gerhard Wiesinger wrote: > > I also had a look at the kernel code again: > http://lxr.free-electrons.com/source/kernel/time/timekeeping.c?v=3.17#L493 > 499 do { > 500 seq = read_seqcount_begin(&tk_core.seq); > 501 > 502 ts->tv_sec = tk->xtime_sec; > 503 nsecs = timekeeping_get_ns(&tk->tkr); > 504 > 505 } while (read_seqcount_retry(&tk_core.seq, seq)); > > So it looks like that the seqcount always changes and therefore loops > forever here (as far as I digged it down this is the only loop here). > > Might be something wrong with the memory barriers in recent qemu-kvm > releases?
No, that's not possible. Unless you pause/resume or migrate the VM, all of the handling of kvmclock is entirely in the kernel. Paolo
