On Mon, Jun 10, 2024 at 10:19 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > > On Fri, Jun 07, 2024 at 01:30:34PM +0200, Jiri Pirko wrote: > > Fri, Jun 07, 2024 at 12:23:37PM CEST, mst@xxxxxxxxxx wrote: > > >On Fri, Jun 07, 2024 at 11:57:37AM +0200, Jiri Pirko wrote: > > >> >True. Personally, I would like to just drop orphan mode. But I'm not > > >> >sure others are happy with this. > > >> > > >> How about to do it other way around. I will take a stab at sending patch > > >> removing it. If anyone is against and has solid data to prove orphan > > >> mode is needed, let them provide those. > > > > > >Break it with no warning and see if anyone complains? > > > > This is now what I suggested at all. > > > > >No, this is not how we handle userspace compatibility, normally. > > > > Sure. > > > > Again: > > > > I would send orphan removal patch containing: > > 1) no module options removal. Warn if someone sets it up > > 2) module option to disable napi is ignored > > 3) orphan mode is removed from code > > > > There is no breakage. Only, hypotetically performance downgrade in some > > hypotetical usecase nobody knows of. > > Performance is why people use virtio. It's as much a breakage as any > other bug. The main difference is, with other types of breakage, they > are typically binary and we can not tolerate them at all. A tiny, > negligeable performance regression might be tolarable if it brings > other benefits. I very much doubt avoiding interrupts is > negligeable though. And making code simpler isn't a big benefit, > users do not care. It's not just making code simpler. As discussed in the past, it also fixes real bugs. > > > My point was, if someone presents > > solid data to prove orphan is needed during the patch review, let's toss > > out the patch. > > > > Makes sense? > > It's not hypothetical - if anything, it's hypothetical that performance > does not regress. And we just got a report from users that see a > regression without. So, not really. Probably, but do we need to define a bar here? Looking at git history, we didn't ask a full benchmark for a lot of commits that may touch performance. Thanks > > > > > > > > >-- > > >MST > > > >
