Re: Live Migration ToDo

[Artyom]

Yes, the original postcopy paper (https://kartikgopalan.github.io/publications/hines09postcopy_osr.pdf) suggests optimizations. For example, prepaging uses hints from the VM's page access patterns to reduce both the number of major network faults and the duration of the migration phase. After examining the code in migration/, I could not find any mention of these optimizations. Perhaps the ideas from the paper have already been tried to implement in QEMU, but they were abandoned?

On Tue, Apr 26, 2022 at 1:51 AM Peter Xu <peterx@redhat.com> wrote:

On Tue, Apr 26, 2022 at 01:39:58AM +0300, Artyom wrote:
> Thank you for your response. Yes, I would like to work on some task, and
> eventually I would like to use it as my student project. For example, it
> might be possible to implement the technique from the article Post-Copy,
> Hines, 2009: demand paging, active push, prepaging and dynamic
> self-ballooning. As far as I understood from the postcopy documentation,
> the pages are pushed sequentially, but it is possible to implement a new
> prepaging strategy. Or are there any obstacles to implementing the ideas of
> this paper in QEMU?

I'm a bit confused.  Firstly, Dave implemented postcopy for QEMU years ago,
please see migration/postcopy-ram.c.  Or do you mean you want to implement
some specific optimization for QEMU's postcopy?

Thanks,

--
Peter Xu