On Mon, 2007-10-15 at 19:35 -0500, Matt Mackall wrote: > Perhaps we need something like: > > flags = page->flags; > userflags = > FLAG_BIT(USER_REFERENCED, flags & PG_referenced) | > ... > > etc. for the flags we want to export. This will let us change to > > FLAG_BIT(USER_SLAB, PageSlab(page)) | > > if we make a virtual slab bit.
Yeah, that looks like a pretty sane scheme. Do we want to be any more abstract about it? Perhaps instead of USER_SLAB, it should be USER_KERNEL_INTERNAL, or USER_KERNEL_USE. The slab itself is going away as we speak. :) > And it shows up in grep. > > Unfortunately, i386 test_bit is an asm inline and not a macro so we > can't hope for the compiler to fold up a bunch of identity bit > mappings for us. We could also Yeah, that looks like a pretty sane scheme. Do we want to be any more abstract about it? Perhaps instead of USER_SLAB, it should be USER_KERNEL_INTERNAL, or USER_KERNEL_USE. The slab itself is going away as we speak. For the bits that we want to export, we could also add the unoptimized access functions for any that don't already have them: #define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) Anybody changing bit behavior will certainly go check all of the callers, such as ClearPageReserved() *and* __ClearPageReserved(). -- Dave - 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/
