Linus Torvalds writes: (Summary) It's not like it's
per-thread, only per process, and very few people have so many
processes that a page per process matters.
processes that a page per process matters.
But regardless, I think we're better off with a "wait and see" approach. IOW, try to use 5-level whenever possible for now, and _if_ somebody actually can show that 4-level page tables perform better or have some other advantage, we can then try to be clever later when it's all tested and it's just an optimization, not a "that code won't even run normally and gets basically zero coverage".
normally and gets basically zero coverage".
Linus
Linus
Linus
processes that a page per process matters.
But regardless, I think we're better off with a "wait and see" approach. IOW, try to use 5-level whenever possible for now, and _if_ somebody actually can show that 4-level page tables perform better or have some other advantage, we can then try to be clever later when it's all tested and it's just an optimization, not a "that code won't even run normally and gets basically zero coverage".
normally and gets basically zero coverage".
Linus
Linus
Linus