On Thu, 13 Jan 2000, Linus Torvalds wrote:
>Basically, my argument is that there is no way "swap_out()" can really
>target any special zone, except by avoiding to do the final stage in a
>long sequence of stages that it has already done. I think that's just
>completely wasteful - doing all the work, and then at the last minute
>deciding to not use the work after all. Especially as we don't really have
>any good reason to believe that it's the right thing in the first place.
The only problem in what you are suggesting is that you may end swapping
out also the wrong pages. Suppose you want to allocate 4k of DMA
memory. Why should the machine swapout lots of mbytes of data while it
could only swapout 4k? And after each swapout we have to restart from the
vma because to swapout we have to drop the pagetable lock and so the
mappings can be changed from under us.
>So that's why I think the page table walker should be completely
>zone-blind, and just not care. It's likely to be more "balanced" that way
>anyway.
The swapout will be definitely more balanced but we may end doing not
necesary swapouts.
Andrea
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Jan 15 2000 - 21:00:23 EST