Messages in this thread |  | | | Date | Thu, 13 Nov 2008 21:22:55 -0800 | | From | Jeremy Fitzhardinge <> | | Subject | Re: [PATCH 1/2] mm: implement remap_pfn_range with apply_to_page_range |
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Nick Piggin wrote: > On Friday 14 November 2008 13:56, Jeremy Fitzhardinge wrote: > >> Nick Piggin wrote: >> >>> This isn't performance critical to anyone? >>> >> The only difference should be between having the specialized code and an >> indirect function call, no? >> > > Indirect function call per pte. It's going to be slower surely. >
Yes, though changing the calling convention to handle (up to) a whole page worth of ptes in one call would be fairly simple I think.
> It is accepted practice to (carefully) duplicate the page table walking > functions in memory management code. I don't think that's a problem, > there is already so many instances of them (just be sure to stick to > exactly the same form and variable names, and any update or bugfix to > any of them is trivially applicable to all). >
I think that's pretty awful practice, frankly, and I'd much prefer there to be a single iterator function which everyone uses. The open-coded iterators everywhere just makes it completely impractical to even think about other kinds of pagetable structures. (Of course we have at least two "general purpose" pagetable walkers now...)
J
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