On Wed, Jan 17, 2024 at 03:06:15PM -0300, Fabiano Rosas wrote:
> Oh no, you're right. Because of p->pending_job. And thinking about
> p->pending_job, wouldn't a trylock to the same job while being more
> explicit?
>
> next_channel %= migrate_multifd_channels();
> for (i = next_channel;; i = (i + 1) % migrate_multifd_channels()) {
> p = &multifd_send_state->params[i];
>
> if(qemu_mutex_trylock(&p->mutex)) {
> if (p->quit) {
> error_report("%s: channel %d has already quit!", __func__, i);
> qemu_mutex_unlock(&p->mutex);
> return -1;
> }
> next_channel = (i + 1) % migrate_multifd_channels();
> break;
> } else {
> /* channel still busy, try the next one */
> }
> }
> multifd_send_state->pages = p->pages;
> p->pages = pages;
> qemu_mutex_unlock(&p->mutex);
We probably can't for now; multifd_send_thread() will unlock the mutex
before the iochannel write()s, while the write()s will need those fields.
> Ok, then I can take block->pages_offset and block->host from the
> ramblock. I think I prefer something like this, that way we can be
> explicit about the migration assumptions.
I'm glad we reached an initial consensus. Yes let's put that in
migration/; I won't expect this code will be used by other iochannel users.
--
Peter Xu
