Re: [Qemu-devel] [PATCH v7 41/42] Disable mlock around incoming postcopy

[Juan Quintela]

Amit Shah <address@hidden> wrote:
> On (Tue) 14 Jul 2015 [17:22:13], Juan Quintela wrote:
>> "Dr. David Alan Gilbert (git)" <address@hidden> wrote:
>
>> > +    if (enable_mlock) {
>> > +        if (os_mlock() < 0) {
>> > +            error_report("mlock: %s", strerror(errno));
>> > +            /*
>> > +             * It doesn't feel right to fail at this point, we have a 
>> > valid
>> > +             * VM state.
>> > +             */
>> 
>> realtime_init() exit in case of os_mlock() fails, so current code is:
>
> Yea, I was wondering the same - but then I thought: would the realtime
> case want a migration to happen at all?

Then disable migration with realtime looks like saner.  But that
decission don't belong to this series.

>
>> - we start qemu with mlock requset
>> - we mlock memory
>> - we start postcopy
>> - we munlock memory
>> - we mlock memory
>> 
>> I wmill really, really preffer having a check if memory is mlocked, and
>> it that case, just abort migration altogether.  Or better still, wait to
>> enable mlock *until* we have finished postcopy, no?
>
>               Amit