On Wed, Feb 14, 2024 at 12:02:30AM +0100, David Hildenbrand wrote: > On 13.02.24 23:59, Suren Baghdasaryan wrote: > > On Tue, Feb 13, 2024 at 2:50 PM Kent Overstreet > > <kent.overstreet@xxxxxxxxx> wrote: > > > > > > On Tue, Feb 13, 2024 at 11:48:41PM +0100, David Hildenbrand wrote: > > > > On 13.02.24 23:30, Suren Baghdasaryan wrote: > > > > > On Tue, Feb 13, 2024 at 2:17 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > > > > > > > > > > > > On 13.02.24 23:09, Kent Overstreet wrote: > > > > > > > On Tue, Feb 13, 2024 at 11:04:58PM +0100, David Hildenbrand wrote: > > > > > > > > On 13.02.24 22:58, Suren Baghdasaryan wrote: > > > > > > > > > On Tue, Feb 13, 2024 at 4:24 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > > > > > > > > > > > > > > > > > On Mon 12-02-24 13:38:46, Suren Baghdasaryan wrote: > > > > > > > > > > [...] > > > > > > > > > > > We're aiming to get this in the next merge window, for 6.9. The feedback > > > > > > > > > > > we've gotten has been that even out of tree this patchset has already > > > > > > > > > > > been useful, and there's a significant amount of other work gated on the > > > > > > > > > > > code tagging functionality included in this patchset [2]. > > > > > > > > > > > > > > > > > > > > I suspect it will not come as a surprise that I really dislike the > > > > > > > > > > implementation proposed here. I will not repeat my arguments, I have > > > > > > > > > > done so on several occasions already. > > > > > > > > > > > > > > > > > > > > Anyway, I didn't go as far as to nak it even though I _strongly_ believe > > > > > > > > > > this debugging feature will add a maintenance overhead for a very long > > > > > > > > > > time. I can live with all the downsides of the proposed implementation > > > > > > > > > > _as long as_ there is a wider agreement from the MM community as this is > > > > > > > > > > where the maintenance cost will be payed. So far I have not seen (m)any > > > > > > > > > > acks by MM developers so aiming into the next merge window is more than > > > > > > > > > > little rushed. > > > > > > > > > > > > > > > > > > We tried other previously proposed approaches and all have their > > > > > > > > > downsides without making maintenance much easier. Your position is > > > > > > > > > understandable and I think it's fair. Let's see if others see more > > > > > > > > > benefit than cost here. > > > > > > > > > > > > > > > > Would it make sense to discuss that at LSF/MM once again, especially > > > > > > > > covering why proposed alternatives did not work out? LSF/MM is not "too far" > > > > > > > > away (May). > > > > > > > > > > > > > > > > I recall that the last LSF/MM session on this topic was a bit unfortunate > > > > > > > > (IMHO not as productive as it could have been). Maybe we can finally reach a > > > > > > > > consensus on this. > > > > > > > > > > > > > > I'd rather not delay for more bikeshedding. Before agreeing to LSF I'd > > > > > > > need to see a serious proposl - what we had at the last LSF was people > > > > > > > jumping in with half baked alternative proposals that very much hadn't > > > > > > > been thought through, and I see no need to repeat that. > > > > > > > > > > > > > > Like I mentioned, there's other work gated on this patchset; if people > > > > > > > want to hold this up for more discussion they better be putting forth > > > > > > > something to discuss. > > > > > > > > > > > > I'm thinking of ways on how to achieve Michal's request: "as long as > > > > > > there is a wider agreement from the MM community". If we can achieve > > > > > > that without LSF, great! (a bi-weekly MM meeting might also be an option) > > > > > > > > > > There will be a maintenance burden even with the cleanest proposed > > > > > approach. > > > > > > > > Yes. > > > > > > > > > We worked hard to make the patchset as clean as possible and > > > > > if benefits still don't outweigh the maintenance cost then we should > > > > > probably stop trying. > > > > > > > > Indeed. > > > > > > > > > At LSF/MM I would rather discuss functonal > > > > > issues/requirements/improvements than alternative approaches to > > > > > instrument allocators. > > > > > I'm happy to arrange a separate meeting with MM folks if that would > > > > > help to progress on the cost/benefit decision. > > > > Note that I am only proposing ways forward. > > > > > > > > If you think you can easily achieve what Michal requested without all that, > > > > good. > > > > > > He requested something? > > > > Yes, a cleaner instrumentation. Unfortunately the cleanest one is not > > possible until the compiler feature is developed and deployed. And it > > still would require changes to the headers, so don't think it's worth > > delaying the feature for years. > > > > I was talking about this: "I can live with all the downsides of the proposed > implementationas long as there is a wider agreement from the MM community as > this is where the maintenance cost will be payed. So far I have not seen > (m)any acks by MM developers". > > I certainly cannot be motivated at this point to review and ack this, > unfortunately too much negative energy around here. David, this kind of reaction is exactly why I was telling Andrew I was going to submit this as a direct pull request to Linus. This is an important feature; if we can't stay focused ot the technical and get it done that's what I'll do.
