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    SubjectRe: [PATCH 22/37] move round_up/down to kernel.h
    On 01/19/2010 09:57 AM, Christoph Lameter wrote:
    > On Fri, 15 Jan 2010, Yinghai Lu wrote:
    >
    >>
    >> #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
    >>
    >> +/*
    >> + * This looks more complex than it should be. But we need to
    >> + * get the type for the ~ right in round_down (it needs to be
    >> + * as wide as the result!), and we want to evaluate the macro
    >> + * arguments just once each.
    >> + */
    >> +#define __round_mask(x,y) ((__typeof__(x))((y)-1))
    >> +#define round_up(x,y) ((((x)-1) | __round_mask(x,y))+1)
    >> +#define round_down(x,y) ((x) & ~__round_mask(x,y))
    >> +
    >> #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
    >> #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
    >> #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
    >
    > Note the last two lines! We already have roundup(), DIV_ROUND_UP and
    > DIV_ROUND_CLOSEST. Please integrate them properly. Maybe extract
    > __round_mask() from all of them.

    like this, using DIVIDE for all ?

    ---
    include/linux/kernel.h | 14 ++++----------
    1 file changed, 4 insertions(+), 10 deletions(-)

    Index: linux-2.6/include/linux/kernel.h
    ===================================================================
    --- linux-2.6.orig/include/linux/kernel.h
    +++ linux-2.6/include/linux/kernel.h
    @@ -44,19 +44,13 @@ extern const char linux_proc_banner[];

    #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

    -/*
    - * This looks more complex than it should be. But we need to
    - * get the type for the ~ right in round_down (it needs to be
    - * as wide as the result!), and we want to evaluate the macro
    - * arguments just once each.
    - */
    -#define __round_mask(x,y) ((__typeof__(x))((y)-1))
    -#define round_up(x,y) ((((x)-1) | __round_mask(x,y))+1)
    -#define round_down(x,y) ((x) & ~__round_mask(x,y))
    +#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
    +#define rounddown(x, y) (((x) / (y)) * (y))
    +#define round_up(x,y) roundup(x,y)
    +#define round_down(x,y) rounddown(x,y)

    #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
    #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
    -#define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
    #define DIV_ROUND_CLOSEST(x, divisor)( \
    { \
    typeof(divisor) __divisor = divisor; \

    \
     
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      Last update: 2010-01-20 21:31    [W:0.021 / U:87.528 seconds]
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