On Tue 10-12-19 16:52:31, Logan Gunthorpe wrote: [...] > In my opinion, having a coder and reviewer see PAGE_KERNEL and ask if > that makes sense is a benefit. Having it hidden because we don't want > people to think about it is worse, harder to understand and results in > bugs that are more difficult to spot. My experience would disagree here. We have several examples in the MM where an overly complex and versatile APIs led to suble bugs, a lot of copy&pasting and cargo cult programing (just look at the page allocator as a shiny example - e.g. gfp_flags). So I am always trying to be carefull here. > Though, we may be overthinking this: arch_add_memory() is a low level > non-exported API that's currently used in exactly two places. This is a fair argument. Most users are and should be using add_memory(). > I don't > think there's going to be many, if any, valid new use cases coming up > for it in the future. That's more what memremap_pages() is for. OK, fair enough. If this is indeed the simplest way forward then I will not stand in the way. -- Michal Hocko SUSE Labs
