Il 08/07/2013 19:32, Frederic Konrad ha scritto: > Hi everybody, > > We get some issues with reverse execution caused by indeterminism. > > Something catched our attention: > static void icount_warp_rt(void *opaque), cpus.c:276 > > We have the feeling that icount is synchronized with rt_clock, is that > possible?
When the CPU is idle, yes. Note that the same thing happened before the series you linked. This is the relevant code: - /* Wait for either IO to occur or the next - timer event. */ - add = qemu_next_deadline(); - /* We advance the timer before checking for IO. - Limit the amount we advance so that early IO - activity won't get the guest too far ahead. */ - if (add > 10000000) - add = 10000000; - delta += add; - qemu_icount += qemu_icount_round (add); It was adding to the icount while waiting for the next timer event to happen. > According to this Paolo's series > <http://lists.gnu.org/archive/html/qemu-devel/2011-04/msg01271.html> > this must be called when the cpus are sleeping, but > I saw this called frequently during the execution, is that the expected > behaviour? What workload are you running? For anything that is not CPU bound I'd expect that to be the case. Paolo > If not what's the best way to fix that?
