Re: [PATCH v3 2/3] perf mmap: declare type for cpu mask of arbitrary length

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Nov 29, 2019 at 01:04:37PM +0300, Alexey Budankov wrote:
> 
> Declare a dedicated struct map_cpu_mask type for cpu masks of
> arbitrary length. Mask is available thru bits pointer and the
> mask length is kept in nbits field. MMAP_CPU_MASK_BYTES() macro
> returns mask storage size in bytes. perf_mmap__print_cpu_mask()
> function can be used to log text representation of the mask.
> 
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
>  tools/perf/util/mmap.c | 12 ++++++++++++
>  tools/perf/util/mmap.h | 11 +++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
> index 063d1b93c53d..30ff7aef06f2 100644
> --- a/tools/perf/util/mmap.c
> +++ b/tools/perf/util/mmap.c
> @@ -23,6 +23,18 @@
>  #include "mmap.h"
>  #include "../perf.h"
>  #include <internal/lib.h> /* page_size */
> +#include <linux/bitmap.h>
> +
> +#define MASK_SIZE 1023
> +void perf_mmap__print_cpu_mask(struct mmap_cpu_mask *mask, const char *tag)

'mmap_cpu_mask__scnprintf' name follows the name logic we try to use

jirka

> +{
> +	char buf[MASK_SIZE + 1];
> +	size_t len;
> +
> +	len = bitmap_scnprintf(mask->bits, mask->nbits, buf, MASK_SIZE);
> +	buf[len] = '\0';
> +	pr_debug("%p: %s mask[%ld]: %s\n", mask, tag, mask->nbits, buf);
> +}
>  
>  size_t mmap__mmap_len(struct mmap *map)
>  {
> diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
> index bee4e83f7109..598e2def8a48 100644
> --- a/tools/perf/util/mmap.h
> +++ b/tools/perf/util/mmap.h
> @@ -15,6 +15,15 @@
>  #include "event.h"
>  
>  struct aiocb;
> +
> +struct mmap_cpu_mask {
> +	unsigned long *bits;
> +	size_t nbits;
> +};
> +
> +#define MMAP_CPU_MASK_BYTES(m) \
> +	(BITS_TO_LONGS(((struct mmap_cpu_mask *)m)->nbits) * sizeof(unsigned long))
> +
>  /**
>   * struct mmap - perf's ring buffer mmap details
>   *
> @@ -52,4 +61,6 @@ int perf_mmap__push(struct mmap *md, void *to,
>  
>  size_t mmap__mmap_len(struct mmap *map);
>  
> +void perf_mmap__print_cpu_mask(struct mmap_cpu_mask *mask, const char *tag);
> +
>  #endif /*__PERF_MMAP_H */
> -- 
> 2.20.1
>