On Mon, 24 Dec 2018, Michal Hocko wrote: > I didn't and do not plan to break any userspace. You have relied on a > (undocumented) side effect of the implementation at the time. Moreover > you have relied on something that has been explicitly documented to be > unstable. Instead I have provided you with an interface that actually > provides a long term maintainable API. This should be somthing you > should have done at the time when you needed the functionality. > > Backporting a proper API to your or whatever older kernel should quite > easy and use it in a userspace should be as well. > > In the presentce of all this. Do we really have to break the API even > further? If you absolutely insist then I will not argue further but it > strikes me as odd how you keep insisting on bending our APIs, push them > to dark corners for very corner case usecases of yours and potentially > break other usecases. This is by far not the first example. Rather than blaming users for parsing a line in smaps which happened to be the only way to determine whether a vma was eligible to be backed by hugepages, I think you should take responsibility for it. These users are not me, I didn't write any code that parses VmFlags myself, I only get the bug reports about it when you broke it. So I'll reiterate: please do not break userspace. I'm not interested in having a 100 email thread about this when a clear and simple fix exists that actually doesn't break user code.
