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

From: Alexey Budankov
Date: Fri Nov 29 2019 - 10:43:43 EST


On 29.11.2019 16:09, Jiri Olsa wrote:
> 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@xxxxxxxxxxxxxxx>
>> ---
>> 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

Renamed in v4.

Thanks,
Alexey

>
> 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
>>
>
>