On Thu, 15 Feb 2024 10:11:05 +0100 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Feb 14, 2024 at 08:42:54PM +0100, Petr Tesařík wrote: > > On Wed, 14 Feb 2024 19:48:52 +0100 > > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > On Wed, Feb 14, 2024 at 05:31:12PM +0100, Petr Tesařík wrote: > > > > On Wed, 14 Feb 2024 16:11:05 +0100 > > > > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > > On Wed, Feb 14, 2024 at 03:55:24PM +0100, Petr Tesařík wrote: > > > > > > OK, so why didn't I send the whole thing? > > > > > > > > > > > > Decomposition of the kernel requires many more changes, e.g. in linker > > > > > > scripts. Some of them depend on this patch series. Before I go and > > > > > > clean up my code into something that can be submitted, I want to get > > > > > > feedback from guys like you, to know if the whole idea would be even > > > > > > considered, aka "Fail Fast". > > > > > > > > > > We can't honestly consider this portion without seeing how it would > > > > > work, as we don't even see a working implementation that uses it to > > > > > verify it at all. > > > > > > > > > > The joy of adding new frameworks is that you need a user before anyone > > > > > can spend the time to review it, sorry. > > > > > > > > Thank your for a quick assessment. Will it be sufficient if I send some > > > > code for illustration (with some quick&dirty hacks to bridge the gaps), > > > > or do you need clean and nice kernel code? > > > > > > We need a real user in the kernel, otherwise why would we even consider > > > it? Would you want to review a new subsystem that does nothing and has > > > no real users? If not, why would you want us to? :) > > > > Greg, please enlighten me on the process. How is something like this > > supposed to get in? > > If you were in our shoes, what would you want to see in order to be able > to properly review and judge if a new subsystem was ok to accept? > > > Subsystem maintainers will not review code that depends on core features > > not yet reviewed by the respective maintainers. If I add only the API > > and a stub implementation, then it brings no benefit and attempts to > > introduce the API will be dismissed. I would certainly do just that if > > I was a maintainer... > > Exactly, you need a real user. Er, what I was trying to say was rather: You need a real implementation of a core feature before a subsystem maintainer considers using it for their subsystem. But I get your point. I need *both*. > > I could try to pack everything (base infrastructure, arch > > implementations, API users) into one big patch with pretty much > > everybody on the Cc list, but how is that ever going to get reviewed? > > How are we supposed to know if any of this even works at all if you > don't show that it actually works and is useful? Has any of that work > even been done yet? I'm guessing it has (otherwise you wouldn't have > posted this), but you are expecting us to just "trust us, stuff in the > future is going to use this and need it" here. Understood. > Again, we can not add new infrastructure for things that have no users, > nor do you want us to. Ideally you will have at least 3 different > users, as that seems to be the "magic number" that shows that the > api/interface will actually work well, and is flexible enough. Just > one user is great for proof-of-concept, but that usually isn't good > enough to determine if it will work for others (and so it wouldn't need > to be infrastructure at all, but rather just part of that one feature on > its own.) > > > Should I just go and maintain an out-of-tree repo for a few years, > > hoping that it gets merged one day, like bcachefs? Is this the way? > > No, show us how this is going to be used. OK, working on it. > Again, think about what you would want if you had to review this. Review, or merge? For a review, I would want enough information to understand what it is *and* where it is going. As a matter of fact, hpa does not like the x86 implementation. For reasons that I do not fully understand (yet), but if the concept turns out to be impractical, then my submission will serve a purpose, as I can save myself (and anybody else with a similar idea) a lot of work by failing fast. Is this a valid way to get early feedback? Thanks, Petr T
