Re: [Qemu-devel] Debugging Migration

[Denis V. Lunev]

On 10/07/2015 02:02 AM, John Snow wrote:
> On 10/06/2015 06:40 PM, Denis V. Lunev wrote:
> > On 10/06/2015 09:46 PM, John Snow wrote:
> > > Is there a convenient way of "pausing" or stalling a live migration to
> > > allow methodical testing of race conditions?
> > >
> > > I'd like to instrument something along the lines of:
> > >
> > > (1) Live migration begins.
> > > (2) migration is artificially halted or paused, but QEMU is allowed to
> > > run.
> > > (3) Some additional qtest/QMP commands are received and processed.
> > > (4) migration is allowed to resume.
> > >
> > > Does anyone have perhaps even test patches to instrument this sort of
> > > thing, or is it up to detective john to add it if he wants it?
> > >
> > > Thanks,
> > > --js
> > we have performed some experiments with migration "test mode".
> > The idea was to estimate the time to migrate and estimate
> > expected downtime for distributed resource management.
> > In this mode the migration was not performed but all stuff around
> > like dirty bitmap was touched.
> >
> > There are several patches for this in my queue but they are very
> > hackish.
> >
> > Will it help you?
> >
> > Den
> It certainly won't hurt me to look at them if you'll share :)
>
> --js

sent as
[RFC 0/8]  QEMUFile-way to gather VM's memory statistics

Sorry, I have lost threading accidentally.

Once again, that code is dirty and IMHO does not meet QEMU coding
standards at the moment.

Den