On 08/02/2017 14:31, Marcelo Tosatti wrote: > The TSC correction in ptp_kvm_gettime was an attempt to handle > high load situations. Unfortunately it is incorrect because > userspace expects PTP clock reads to happen in the middle point > between realtime clock reads: > > > |* | | | | | | | | | | | |* | | | | | | | | | | | |* | > rt-read-1 ptp-clock-read-1 rt-read-2 > > The TSC correction causes the PTP clock reads to read the clock at: > > |* | | | | | | | | | | | | | | | | |* | | | | | | |* | > rt-read-1 ptp-clock-read-1 rt-read-2 > > So drop the TSC offset correction, increasing precision of synchronization > of an idle guest to <= 10ns. > > Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Applied, thanks. Paolo
