Re: [RFC] nbd: is the add_socket queue freeze needed on the initial (pre-start) connect path?

[Zhichao Huang]

Hi Erkun, Kuai,

Thank you both -- yes, [PATCH v8 0/8] is exactly what we need. It covers
the nbd_add_socket() and nbd_set_size() freezes I was asking about, and
also the blk_mq_update_nr_hw_queues() one in nbd_start_device() that I
hadn't gotten to. Good to see it's already reviewed.

Erkun, I especially like that patch 2 removes the freeze's root cause by
rejecting NBD_SET_SOCK on an active device, rather than relying on the
capacity==0 / bio_check_eod invariant I was reasoning about in my mail --
that's a cleaner and more robust basis for dropping the freeze.

I'll apply the series on our Firecracker + many-core setup and follow up
with our create-latency numbers and a Tested-by. Happy to help however
is useful to get it landed.

Thanks again,
Zhichao Huang <huangzhichao.1@xxxxxxxxxxxxx>