* Peter Maydell (peter.mayd...@linaro.org) wrote: > On Thu, 17 Jan 2019 at 09:46, Jason Wang <jasow...@redhat.com> wrote: > > > > > > On 2019/1/15 上午12:33, Zhang Chen wrote: > > > > > > > > > On Sat, Jan 12, 2019 at 12:15 AM Dr. David Alan Gilbert > > > <dgilb...@redhat.com <mailto:dgilb...@redhat.com>> wrote: > > > > > > * Peter Maydell (peter.mayd...@linaro.org > > > <mailto:peter.mayd...@linaro.org>) wrote: > > > > Recently I've noticed that test-filter-mirror has been hanging > > > > intermittently, typically when run on some other TCG architecture. > > > > In the instance I've just looked at, this was with s390x guest on > > > > x86-64 host, though I've also seen it on other host archs and > > > > perhaps with other guests. > > > > > > Watch out to see if you really do see it for other guests; > > > it carefully avoids using virtio-net to avoid vhost; but on s390x it > > > uses virtio-net-ccw - could that hit the vhost it was trying to avoid? > > > > > > > Below is a backtrace, though it seems to be pretty unhelpful. > > > > Anybody got any theories ? Does the mirror test rely on dirty > > > > memory bitmaps like the migration test (which also hangs > > > > occasionally with TCG due to some bug I'm sure we've investigated > > > > in the past) ? > > > > > > I don't think it relies on the CPU at all. > > > > I have no idea about this currently, but Jason and I designed the > > > test case. > > > Add Jason: Have any comments about this ? > > > > > > I can't reproduce this locally with s390x-softmmu. It looks to me the > > test should be independent to any kinds of emulation. It should pass > > when mainloop work. > > I've just seen a hang with ppc64 guest on s390x host, so it is > indeed not specific to s390x guest (and so not specific to > virtio-net either, since the ppc64 guest setup uses e1000).
Hmph, there goes that idea. I guess we need some tracing of the packet flow; do you build with tracing on and can we enable it for a test? Dave > thanks > -- PMM -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
