Messages in this thread |  | | | Date | Wed, 30 Jan 2008 01:05:59 +0100 | | From | Andrea Arcangeli <> | | Subject | Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges |
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On Wed, Jan 30, 2008 at 01:00:39AM +0100, Andrea Arcangeli wrote: > get_user_pages, regular linux writes don't fault unless it's > explicitly writeprotect, which is mandatory in a few archs, x86 not).
actually get_user_pages doesn't fault either but it calls into set_page_dirty, however get_user_pages (unlike a userland-write) at least requires mmap_sem in read mode and the PT lock as serialization, userland writes don't, they just go ahead and mark the pte in hardware w/o faults. Anyway anonymous memory these days always mapped with dirty bit set regardless, even for read-faults, after Nick finally rightfully cleaned up the zero-page trick.
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