Messages in this thread |  | | Date | Mon, 7 Apr 2008 08:02:34 +0200 | From | Andrea Arcangeli <> | Subject | Re: [PATCH] mmu notifier #v11 |
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On Sun, Apr 06, 2008 at 10:45:41PM -0700, Christoph Lameter wrote: > That depends on what the notifier is being used for. Some serialization > with the external mappings has to be done anyways. And its cleaner to have
As far as I can tell no, you don't need to serialize against the secondary mmu page fault in invalidate_page, like you instead have to do in range_begin if you don't unpin the pages in range_end.
> one API that does a lock/unlock scheme. Atomic operations can easily lead > to races.
What races? Note that if you don't want to optimize XPMEM and GRU can feel free to implement their own invalidate_page as this:
invalidate_page(mm, addr) { range_begin(mm, addr, addr+PAGE_SIZE) range_end(mm, addr, addr+PAGE_SIZE) }
There's zero risk of adding races if they do this, but I doubt they want to run as slow as with EMM so I guess they'll exploit the optimization by going lock-free vs the spte page fault in invalidate_page.
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