Messages in this thread | | | Date | Tue, 29 Jan 2002 14:10:10 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: Note describing poor dcache utilization under high memory pressure |
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On Tue, 29 Jan 2002, Oliver Xymoron wrote: > > The "detached mm" approach should be sufficiently parallel to the > read-only page directory entries that the two can use almost the same > framework.
Yes. I suspect that it can be trivially hidden in just two architecture-specific functions, ie something like "detach_pgd(pgd)" and "attach_pgd_entry(mm, address)".
> The downside is faults on reads in the detached case, but that > shouldn't be significantly worse than the original copy, thanks to the > large fanout.
Right. We'd get a few "unnecessary" page faults, but they should be on the order of 0.1% of the necessary ones. In fact, with pre-faulting in sys_fork(), I wouldn't be surprised if the common case is to not have any directory-related page faults at all.
Linus
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