Re: [Qemu-devel] [Spice-devel] Current qemu-master hangs when used with qxl + linux guest
On Tue, Oct 08, 2013 at 04:27:38PM +0200, Hans de Goede wrote: Hi All, I'm having this weird problem with qemu master + spice/qxl using guests. As soon as the guest starts Xorg, I get the following message from qemu: main-loop: WARNING: I/O thread spun for 1000 iterations And from then on the guest hangs and qemu consumes 100% cpu. The qemu console still works, and I can quit qemu that way. Doing ctrl+c + a thread apply all bt in qemy shows one cpu thread waiting for the iothread-lock, and all other threads waiting in poll. This happens both with non kms guests (tried RHEL-6.5, older Fedoras) as well as with kms guests (tried a fully up2date F-19). Since I've not seen any similar reports, I assume it is something with my setup ... I've tried changing various things: -removing the spice agent channel -changing the number of virtual cpus (tried 1 and 2 virtual cpus) -upgrading spice-server to the latest git master But all to no avail. This is with qemu-master build from source on a fully up2date F-20 system, using the F-20 seabios files. If someone has any clever ideas I'll happily try debugging this further. Does the QEMU build in F20 work correctly ? If so that'd give you a starting point from which to 'git bisect' the problem. Daniel -- |: http://berrange.com -o-http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
Re: [Qemu-devel] [Spice-devel] Current qemu-master hangs when used with qxl + linux guest
Hey Hans, On Tue, Oct 08, 2013 at 04:27:38PM +0200, Hans de Goede wrote: I'm having this weird problem with qemu master + spice/qxl using guests. As soon as the guest starts Xorg, I get the following message from qemu: main-loop: WARNING: I/O thread spun for 1000 iterations I've also seen that message when giving a quick try to qemu master today, so it's not just your setup. Christophe pgpVzIFUIkMm2.pgp Description: PGP signature
Re: [Qemu-devel] [Spice-devel] Current qemu-master hangs when used with qxl + linux guest
Hi, On 10/08/2013 04:30 PM, Daniel P. Berrange wrote: On Tue, Oct 08, 2013 at 04:27:38PM +0200, Hans de Goede wrote: Hi All, I'm having this weird problem with qemu master + spice/qxl using guests. As soon as the guest starts Xorg, I get the following message from qemu: main-loop: WARNING: I/O thread spun for 1000 iterations And from then on the guest hangs and qemu consumes 100% cpu. The qemu console still works, and I can quit qemu that way. Doing ctrl+c + a thread apply all bt in qemy shows one cpu thread waiting for the iothread-lock, and all other threads waiting in poll. This happens both with non kms guests (tried RHEL-6.5, older Fedoras) as well as with kms guests (tried a fully up2date F-19). Since I've not seen any similar reports, I assume it is something with my setup ... I've tried changing various things: -removing the spice agent channel -changing the number of virtual cpus (tried 1 and 2 virtual cpus) -upgrading spice-server to the latest git master But all to no avail. This is with qemu-master build from source on a fully up2date F-20 system, using the F-20 seabios files. If someone has any clever ideas I'll happily try debugging this further. Does the QEMU build in F20 work correctly ? Ah, yes it does, good dea. If so that'd give you a starting point from which to 'git bisect' the problem. Yep, note I asked for a clever idea, iow not the big hammer of bisecting :) But since 1.6.0 in F-20 worked it was not such a large bisect, so I went ahead and bisected anyways, which pointed me to commit 7b595f35d8 : aio / timers: Convert mainloop to use timeout After careful review of that commit I had a hunch what might be wrong, and it turned out to be right. So after this mail I'm going to send a patch fixing this. If you want to know the details see the patch, titled: main-loop: Don't lock starve io-threads when main_loop_tlg has pending events Regards, Hans
