Re: [PATCH-v2 1/2] kernel.h: Add DIV_ROUND_UP_ULL andDIV_ROUND_UP_SECTOR_T macro usage

From: Nicholas A. Bellinger
Date: Tue Jul 26 2011 - 04:44:38 EST


On Tue, 2011-07-26 at 07:35 +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
>
> Add new DIV_ROUND_UP_SECTOR_T macro usage for 32-bit architectures requiring
> a new DIV_ROUND_UP_ULL, and existing 64-bit usage with DIV_ROUND_UP.
>
> Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Reported-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
> ---
> include/linux/kernel.h | 8 ++++++++
> 1 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 953352a..e81b647 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -56,6 +56,14 @@
>
> #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
> #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
> +#define DIV_ROUND_UP_ULL(ll,d) \
> + ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
> +
> +#if BITS_PER_LONG == 32
> +# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
> +#else
> +# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
> +#endif
>

Hi Andrew,

Is CONFIG_LBDAF=n usage going to have problems with the above..?

Things are looking as expected AFAICT with some quick tests with
CONFIG_LBDAF=y on i386, but still need to verify the CONFIG_LBDAF=n on
32-bit as well. Any more comments here are appercitated.

Thank you,

--nab



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