Re: [Qemu-devel] virtio-serial-pci very expensive during live migration

[Gonglei (Arei)]

Hi,


> Subject: Re: [Qemu-devel] virtio-serial-pci very expensive during live 
> migration
> 
> Il 06/05/2014 22:01, Chris Friesen ha scritto:
> >
> > It seems like the main problem is that we loop over all the queues,
> > calling virtio_pci_set_host_notifier_internal() on each of them.  That
> > in turn calls memory_region_add_eventfd(), which calls
> > memory_region_transaction_commit(), which scans over all the address
> > spaces, which seems to take the vast majority of the time.
> 
> Yes, you can wrap the entire loop with memory_region_transaction_begin
> and memory_region_transaction_commit.  Can you try that?
> 
> Paolo
We have discussed the issue before:
https://lists.gnu.org/archive/html/qemu-devel/2014-03/msg00421.html

According Paolo's advice, I have finished the patch and tested it work well.

I will post the patch later.


Best regards,
-Gonglei