Re: [Libguestfs] [PATCH libnbd 2/2] socket-activation: Allow multiple connections

On Sun, Nov 7, 2021 at 4:00 PM Richard W.M. Jones <rjones(a)redhat.com&gt; wrote: > > On Sun, Nov 07, 2021 at 03:27:47PM +0200, Nir Soffer wrote: > > When using qemu-nbd with systemd socket activation, trying to connect > > additional clients concurrently fails with: > > > > nbd_connect_uri: connect: server backlog overflowed, see > > https://bugzilla.redhat.com/1925045: Resource temporarily > > unavailable > > > > But this bug was fixed in qemu-nbd long time ago; turns out that libnbd > > has the same bug, creating the server socket with: > > > > listen(s, 1); > > > > Use SOMAXCONN so we can have multiple connections for better > > performance. I think this can be very useful for nbdcopy. > > Apart from the problems in API mentioned in the other review, this > patch ordering isn't bisectable. > > What's the motivation for this patch series? Why is it not bissectable?

In general, I like to add first tests before I modify code. In the best case the test also reproduces the issue. Having a failing test in the build is better than having a bug. In this case the test is too simple, we need to use multiple threads to reproduce the issue. We can switch the order if you don't like this approach. Nir