Mon, Jun 17, 2024 at 03:44:55AM CEST, jasowang@xxxxxxxxxx wrote: >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 Moreover, there is no "benchmark" to run anyway, is it? >performance. > >Thanks > >> >> > >> > > >> > >-- >> > >MST >> > > >> >
