Roland> Yes, because the kernel may go through and unmap pages Roland> from userspace while trying to swap. Since we have the Roland> page locked in the kernel, the physical page won't go Roland> anywhere, but userspace might end up with a different page Roland> mapped at the same virtual address.
Andrew> That shouldn't happen. If get_user_pages() has elevated Andrew> the refcount on a page then the following can happen: ... Andrew> IOW: while the page has an elevated refcount from Andrew> get_user_pages(), that physical page is 100% pinned. Andrew> Once you've done the set_page_dirty+put_page(), the page Andrew> is again under control of the VM. Hmm... I've never tested it first hand but Libor assures me there is a something like what I said. Libor, did I get the explanation right? - R. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/