On Fri, 2008-02-15 at 08:08 +0100, Ingo Molnar wrote: > * Huang, Ying <[EMAIL PROTECTED]> wrote: > > > On Thu, 2008-02-14 at 17:12 +0100, Ingo Molnar wrote: > > > this is indeed a bug (we change the attributes for a larger area than > > > needed), but your fix is unclean. Find below a cleaner solution. > > > > > > Ying, if you agree with this fix could you please test and ACK it before > > > we push it to Linus? (this fix is also in the latest x86.git#mm) > > > > I think the patch following may be better, because it is possible that > > the EFI_PAGE_SHIFT and PAGE_SHIFT are different. > > right now, EFI page size is 4096: > > include/linux/efi.h:#define EFI_PAGE_SHIFT 12 > > i doubt we'll ever change PAGE_SIZE on x86 - ia64's variable lowlevel > pagesizes are not particularly useful IMO. I think we'll at most have > some generic kernel feature that allows a larger PAGE_CACHE_SHIFT - but > on the lowlevel MMU level we'll always stay at 4K. > > and i doubt EFI_PAGE_SHIFT would want to (ever) go away from 12 either.
After looking up in UEFI specification, I found that it is specified by UEFI specification 2.1 (section 6.2, page 124) that the NumberOfPages (num_pages) of EFI_MEMORY_DESCRIPTOR (efi_memory_desc_t) must be "Number of 4KB pages in the memory region". So we need not worry about potential EFI_PAGE_SHIFT changes. Best Regards, Huang Ying > So perhaps, at least as far as arch/x86/kernel/efi*.c files go, it would > be cleaner to just replace EFI_PAGE_SHIFT with PAGE_SHIFT and > EFI_PAGE_SIZE with PAGE_SIZE? -- 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/
