Re: [Qemu-devel] [PATCH v2 0/5] dataplane snapshot fixes

[Paolo Bonzini <pbonzini@redhat.com>]

On 27/10/2015 15:09, Denis V. Lunev wrote:
> The following test
>     while /bin/true ; do
>         virsh snapshot-create rhel7
>         sleep 10
>         virsh snapshot-delete rhel7 --current
>     done
> with enabled iothreads on a running VM leads to a lot of troubles: hangs,
> asserts, errors.
> 
> Though (in general) HMP snapshot code is terrible. I think it should be
> dropped at once and replaced with blkdev transactions code. Though is
> could not fit to QEMU 2.5/stable at all.
> 
> Anyway, I think that the construction like
>     assert(aio_context_is_locked(aio_context));
> should be widely used to ensure proper locking.
> 
> Changes from v1:
> - aio-context locking added
> - comment is rewritten
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Stefan Hajnoczi <stefanha@redhat.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>

For patches 4-5:

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

For patches 1-3 I'm not sure, because we will remove RFifoLock
relatively soon and regular pthread recursive mutexes do not have an
equivalent of rfifolock_is_locked.

Paolo