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    Subject[PATCH] Use bool for boolean flag in printk_once()
    Date
    Using the type bool (instead of int) for the __print_once flag in the
    printk_once() macro matches the intent of the code better, and allows
    the compiler to generate smaller code; eg a typical callsite with gcc
    4.3.3 on i386:

    add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-6 (-6)
    function old new delta
    static.__print_once 4 1 -3
    get_cpu_vendor 146 143 -3

    Saving 6 bytes of object size per callsite by slightly improving the
    readability of the source seems like a win to me.

    Signed-off-by: Roland Dreier <rolandd@cisco.com>
    ---
    include/linux/kernel.h | 4 ++--
    1 files changed, 2 insertions(+), 2 deletions(-)

    diff --git a/include/linux/kernel.h b/include/linux/kernel.h
    index d6320a3..f828ce9 100644
    --- a/include/linux/kernel.h
    +++ b/include/linux/kernel.h
    @@ -249,10 +249,10 @@ extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
    * Print a one-time message (analogous to WARN_ONCE() et al):
    */
    #define printk_once(x...) ({ \
    - static int __print_once = 1; \
    + static bool __print_once = true; \
    \
    if (__print_once) { \
    - __print_once = 0; \
    + __print_once = false; \
    printk(x); \
    } \
    })

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