Messages in this thread | | | Date | Mon, 25 Apr 2005 17:42:36 -0500 | From | Timur Tabi <> | Subject | Re: [PATCH][RFC][0/4] InfiniBand userspace verbs implementation |
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Andrew Morton wrote:
> This is because there is no file descriptor or anything else associated > with the pages which permits the kernel to clean stuff up on unclean > application exit. Also there are the obvious issues with permitting > pinning of unbounded amounts of memory.
Then that might explain the "bug" that we're seeing with get_user_pages(). We've been assuming that get_user_pages() mappings are permanent.
Well, I was just about to re-implement get_user_pages() support in our driver to demonstrate the bug. I guess I'll hold off on that.
If you look at the Infiniband code that was recently submitted, I think you'll see it does exactly that: after calling mlock(), the driver calls get_user_pages(), and it stores the page mappings for future use.
-- Timur Tabi Staff Software Engineer timur.tabi@ammasso.com
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