Re: [RFC PATCH 0/2] io_uring: add IPC channel infrastructure

[Daniel Hodges]

On Mon, Mar 16, 2026 at 04:17:05PM -0600, Jens Axboe wrote:
> On 3/16/26 6:49 AM, Daniel Hodges wrote:
> > On Sat, Mar 14, 2026 at 10:54:15AM -0600, Jens Axboe wrote:
> >> On 3/14/26 7:50 AM, Daniel Hodges wrote:
> >>> On Thu, Mar 13, 2026 at 01:07:37PM +0000, Daniel Hodges wrote:
> >>>> Performance (virtme-ng VM, single-socket, msg_size sweep 64B-32KB):
> >>>>
> >>>>   Point-to-point latency (64B-32KB messages):
> >>>>     io_uring unicast: 597-3,185 ns/msg (within 1.5-2.5x of pipe for small msgs)
> >>>
> >>> Benchmark sources used to generate the numbers in the cover letter:
> >>>
> >>>   io_uring IPC modes (broadcast, multicast, unicast):
> >>>     https://gist.github.com/hodgesds/fbcd8bb8497bc0ec2bf1f95244a984fe#file-io_uring_ipc_bench-c
> >>>
> >>>   IPC comparison (pipes, unix sockets, shm+eventfd):
> >>>     https://gist.github.com/hodgesds/fbcd8bb8497bc0ec2bf1f95244a984fe#file-ipc_comparison_bench-c
> >>
> >> Thanks for sending these, was going to ask you about them. I'll take a
> >> look at your patches Monday.
> >>
> >> -- 
> >> Jens Axboe
> > 
> > No rush, thanks for taking the time!
> 
> I took a look - and I think it's quite apparent that it's a AI vibe
> coded patch. Hence my first question is, do you have a specific use case
> in mind? Or phrased differently, was this done for a specific use case
> you have and want to pursue, or was it more of a "let's see if we can do
> this and what it'd look like" kind of thing?
> 
> I have a lot of comments on the patch itself, but let's establish the
> motivation here first.
> 
> -- 
> Jens Axboe

I've been helping Alexandre prototype a D-Bus broker replacement that
scales better on large machines. Here's some docs/benchmarks:
https://github.com/fiorix/sbus/blob/main/sbus-broker/docs/analysis.md

The idea for this RFC by trying to come up with a design if D-Bus was to
be built from the ground so that it could scale on large machines. D-Bus
was built because the kernel never really had a broadcast/multicast
solution for IPC and kdbus demonstrated that moving dbus into the kernel
wasn't viable either. So that's where I sort of landed on the idea of
what if io_uring could be used for this type of IPC.

There isn't a working io_uring backed D-Bus implementation yet as
it would require features that aren't in this patch such a handling
credentials etc. I fully acknowledge I had AI help in working on this,
but if this idea make sense I would appreciate some human direction. If
it seems like it could be feasible from your pespective I would like to
try to give it a proper attempt. Thanks!

-Daniel