Re: [PATCH 1/3] perf tools: Add test_and_set_bit function

From: Namhyung Kim
Date: Tue Nov 04 2014 - 03:39:25 EST


Hi Jiri,

On Sun, 26 Oct 2014 23:44:03 +0100, Jiri Olsa wrote:
> Set a bit and return its old value. Stolen from kernel
> sources, will be used in next patches.
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>

For all 3 patches,

Acked-by: Namhyung Kim <namhyung@xxxxxxxxx>

Thanks,
Namhyung


> ---
> tools/perf/util/include/linux/bitmap.h | 17 +++++++++++++++++
> tools/perf/util/include/linux/bitops.h | 2 ++
> 2 files changed, 19 insertions(+)
>
> diff --git a/tools/perf/util/include/linux/bitmap.h b/tools/perf/util/include/linux/bitmap.h
> index 01ffd12dc791..40bd21488032 100644
> --- a/tools/perf/util/include/linux/bitmap.h
> +++ b/tools/perf/util/include/linux/bitmap.h
> @@ -46,4 +46,21 @@ static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
> __bitmap_or(dst, src1, src2, nbits);
> }
>
> +/**
> + * test_and_set_bit - Set a bit and return its old value
> + * @nr: Bit to set
> + * @addr: Address to count from
> + */
> +static inline int test_and_set_bit(int nr, unsigned long *addr)
> +{
> + unsigned long mask = BIT_MASK(nr);
> + unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
> + unsigned long old;
> +
> + old = *p;
> + *p = old | mask;
> +
> + return (old & mask) != 0;
> +}
> +
> #endif /* _PERF_BITOPS_H */
> diff --git a/tools/perf/util/include/linux/bitops.h b/tools/perf/util/include/linux/bitops.h
> index dadfa7e54287..c3294163de17 100644
> --- a/tools/perf/util/include/linux/bitops.h
> +++ b/tools/perf/util/include/linux/bitops.h
> @@ -15,6 +15,8 @@
> #define BITS_TO_U64(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
> #define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
> #define BITS_TO_BYTES(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE)
> +#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
> +#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
>
> #define for_each_set_bit(bit, addr, size) \
> for ((bit) = find_first_bit((addr), (size)); \
--
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