Re: get_user_pages ?

From: Nick Piggin
Date: Sat Apr 22 2006 - 15:56:58 EST


Mark Hounschell wrote:

OK, I'd suggest either using vm_insert_page, or converting it all over
to a ->nopage handler then.



I set the bit back on after get_user_pages and now I seem to be OK.

You've looked at the code some obviously. What is in my future WRT these
changes being made that you referenced above and the depreciation of
some of the calls in use. Given my situation, do you foresee anything
that will keep me from being able to get valid bus addresses for my pte?

Well remap_pfn_range / io_remap_pfn_range is a good option, but it
shouldn't really support get_user_pages so I suspect you are just
lucky there (ie. on some platforms you might not have a struct page
for your bus address, and other times the final put_page will try
to free the page).

If you definitely have struct pages, vm_insert_page is an option,
unless the memory is allocated with dma_alloc_* or similar, in
which case you should probably be using remap_pfn_range.

--
SUSE Labs, Novell Inc.
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