Backporting to stable... Re: [GIT PULL] io_uring thread worker change

[Stefan Metzmacher <metze@samba.org>]

Hi Jens,

> I'm sure we're going to find little things to patch up after this
> series, but testing has been pretty thorough, from the usual regression
> suite to production. Any issue that may crop up should be manageable.
> There's also a nice series of further reductions we can do on top of
> this, but I wanted to get the meat of it out sooner rather than later.
> The general worry here isn't that it's fundamentally broken. Most of the
> little issues we've found over the last week have been related to just
> changes in how thread startup/exit is done, since that's the main
> difference between using kthreads and these kinds of threads. In fact,
> if all goes according to plan, I want to get this into the 5.10 and 5.11
> stable branches as well.

That would mean that IORING_FEAT_SQPOLL_NONFIXED would be implicitly be backported
from 5.11 to 5.10, correct?

I'm wondering if I can advice people to move to 5.10 (as it's an lts release)
in order to get a kernel that is most likely very useful to use in combination
with Samba's drafted usage of io_uring, where I'd like to use IORING_FEAT_SQPOLL_NONFIXED
and IORING_FEAT_NATIVE_WORKERS in order to use SENDMSG/RECVMSG with msg_control buffers (where
the control buffers may reference file descriptors).

Thanks!
metze