Peter Xu <pet...@redhat.com> writes: > Blocktime so far only cares about the time one vcpu (or the whole system) > got blocked. It would be also be helpful if it can also report the latency > of page requests, which could be very sensitive during postcopy. > > Blocktime itself is sometimes not very important, especially when one > thinks about KVM async PF support, which means vCPUs are literally almost > not blocked at all because the guest OS is smart enough to switch to > another task when a remote fault is needed. > > However, latency is still sensitive and important because even if the guest > vCPU is running on threads that do not need a remote fault, the workload > that accesses some missing page is still affected. > > Add two entries to the report, showing how long it takes to resolve a > remote fault. Mention in the QAPI doc that this is not the real average > fault latency, but only the ones that was requested for a remote fault. > > Unwrap get_vcpu_blocktime_list() so we don't need to walk the list twice, > meanwhile add the entry checks in qtests for all postcopy tests. > > Cc: Markus Armbruster <arm...@redhat.com> > Cc: Dr. David Alan Gilbert <d...@treblig.org> > Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Fabiano Rosas <faro...@suse.de>
