Hi,
On Sat, 8 Mar 2025 at 04:18, Peter Xu <[email protected]> wrote:
> Please move all of them at the entry of postcopy_start().
* Okay.
> [1]
>
> > +int qemu_savevm_state_complete_multifd(QEMUFile *f)
> I still like the name I provided because it's more generic, above [1].
===
> Maybe the easiest as of now is one more hook like
> qemu_savevm_state_complete_precopy_prepare(),
===
* ie. use -> 'qemu_savevm_state_complete_precopy_prepare' name?
Should it be _postcopy_prepare?
>> + if (strcmp(se->idstr, "ram")) {
>> + continue;
>> + }
>> + save_section_header(f, se, QEMU_VM_SECTION_END);
>
> Maybe it should be SECTION_PART.
* Will try with SECTION_PART.
> So we provide all iterator a chance to
> do something right before switching to postcopy but before VM stop. RAM
> can register.
* ...all iterators a chance to do something? Above function only
processes "ram" entries -> strcmp(se->idstr, "ram").
* ...RAM can register?
> > +
> > + ret = se->ops->save_live_complete_precopy(f, se->opaque);
>
> Maybe we don't want to run the whole iteration but only flush. I think for
> simplicity we can make a new hook.
* ..new hook? I tried calling multifd_ram_flush_and_sync() in place of
->save_live_complete_precopy(), but it crashes QEMU.
> > + end_ts_each = qemu_clock_get_us(QEMU_CLOCK_REALTIME);
> > + trace_vmstate_downtime_save("iterable", se->idstr, se->instance_id,
> > + end_ts_each - start_ts_each);
>
> We do not need to account
> If you do flush and sync, IMHO we can keep the threads there and remove
> this shutdown, as long as we are sure it'll be properly shutdown when
> cleanup. With the assertion in dest threads, I think it should be OK.
* Okay.
Thank you.
---
- Prasad
