On Mon, Aug 08, 2022 at 10:56:45PM +0800, Aaron Lu wrote: > This is an early RFC. While all reviews are welcome, reviewing this code > now will be a waste of time for the x86 subsystem maintainers. I would, > however, appreciate a preliminary review from the folks on the to and cc > list. I'm posting it to the list in case anyone else is interested in > seeing this early version. Last time[1] I tried to merge pages back in direct mapping it lead to substantial performance regression for some workloads. I cannot find the report right now, but I remember it was something graphics related. Have you done any performance evaluation? My take away was that the merge has to be batched. Like log where changes to direct mapping happens and come back to then and merge when the number of changes cross some limit. Also I don't see you handling set_memory_4k(). Huh? [1] https://lore.kernel.org/lkml/20200416213229.19174-1-kirill.shutemov@xxxxxxxxxxxxxxx/ -- Kiryl Shutsemau / Kirill A. Shutemov
