Re: [Qemu-devel] sda abort with virtio-scsi

[Paolo Bonzini]

On 04/02/2016 00:34, Jim Minter wrote:
> I was worried there was
> some way in which the contention could cause an abort and perhaps thence
> the lockup (which does not seem to recover when the host load goes down).

I don't know... It's not the most tested code, but it is not very
complicated either.

The certain points that can be extracted from the kernel messages are:
1) there was a cancellation request that took a long time, >20 seconds;
2) despite taking a long time, it _did_ recover sooner or later because
otherwise you'd not have the lockup splat either.

Paolo

>> Firing the NMI watchdog is fixed in more recent QEMU, which has
>> asynchronous cancellation, assuming you're running RHEL's QEMU 1.5.3
>> (try /usr/libexec/qemu-kvm --version, or rpm -qf /usr/libexec/qemu-kvm).
> 
> /usr/libexec/qemu-kvm --version reports QEMU emulator version 1.5.3
> (qemu-kvm-1.5.3-105.el7_2.3)