On Thu, Jun 04, 2020 at 07:45:40PM +0200, David Hildenbrand wrote: > On 04.06.20 19:22, Daniel Jordan wrote: > > IMHO the root cause of this is really the small block size. Building a cache > > on top to avoid iterating over tons of small blocks seems like papering over > > the problem, especially when one of the two affected paths in boot is a > > The memory block size dictates your memory hot(un)plug granularity. Indeed. > E.g., on powerpc that's 16MB so they have *a lot* of memory blocks. > That's why that's not papering over the problem. Increasing the memory > block size isn't always the answer. Ok. If you don't mind, what's the purpose of hotplugging at that granularity? I'm simply curious. > > cautious check that might be ready to be removed by now[0]: > > Yeah, we discussed that somewhere already. My change only highlighted > the problem. And now that it's cheap, it can just stay unless there is a > very good reason not to do it. Agreed. > > Yeah, but of course it's not as bad as it was now that it's fully parallelized. > > Right. I also observed that computing if a zone is contiguous can be > expensive. That's right, I remember that. It's on my list :)
