Re: [PATCH 1/2] perf: drop unneeded bitmap_zero() in util/header.c
From: Yury Norov
Date: Tue Jul 24 2018 - 16:27:54 EST
On Sat, Jun 23, 2018 at 10:35:01AM +0300, Yury Norov wrote:
> On top of next-20180622.
>
> bitmap_zero() is called after bitmap_alloc() in perf code. But
> bitmap_alloc() internally uses calloc() which guarantees that allocated
> area is zeroed. So following bitmap_zero is unneeded. Drop it.
>
> This happened because of confusing name for bitmap allocator. It
> should has name bitmap_zalloc instead of bitmap_alloc. This series:
> https://lkml.org/lkml/2018/6/18/841
> introduces new API for bitmap allocations in kernel, and functions
> there are named correctly. Following patch propogates the API to tools,
> and fixes naming issue.
>
> Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
Ping?
> ---
> tools/perf/tests/bitmap.c | 2 --
> tools/perf/tests/mem2node.c | 5 +----
> tools/perf/util/header.c | 3 ---
> 3 files changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/tools/perf/tests/bitmap.c b/tools/perf/tests/bitmap.c
> index 47bedf25ba69..96e7fc1ad3f9 100644
> --- a/tools/perf/tests/bitmap.c
> +++ b/tools/perf/tests/bitmap.c
> @@ -16,8 +16,6 @@ static unsigned long *get_bitmap(const char *str, int nbits)
> bm = bitmap_alloc(nbits);
>
> if (map && bm) {
> - bitmap_zero(bm, nbits);
> -
> for (i = 0; i < map->nr; i++)
> set_bit(map->map[i], bm);
> }
> diff --git a/tools/perf/tests/mem2node.c b/tools/perf/tests/mem2node.c
> index 0c3c87f86e03..d8e3d49d3638 100644
> --- a/tools/perf/tests/mem2node.c
> +++ b/tools/perf/tests/mem2node.c
> @@ -24,11 +24,8 @@ static unsigned long *get_bitmap(const char *str, int nbits)
> bm = bitmap_alloc(nbits);
>
> if (map && bm) {
> - bitmap_zero(bm, nbits);
> -
> - for (i = 0; i < map->nr; i++) {
> + for (i = 0; i < map->nr; i++)
> set_bit(map->map[i], bm);
> - }
> }
>
> if (map)
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 540cd2dcd3e7..3a6bec22baa3 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -279,8 +279,6 @@ static int do_read_bitmap(struct feat_fd *ff, unsigned long **pset, u64 *psize)
> if (!set)
> return -ENOMEM;
>
> - bitmap_zero(set, size);
> -
> p = (u64 *) set;
>
> for (i = 0; (u64) i < BITS_TO_U64(size); i++) {
> @@ -1285,7 +1283,6 @@ static int memory_node__read(struct memory_node *n, unsigned long idx)
> return -ENOMEM;
> }
>
> - bitmap_zero(n->set, size);
> n->node = idx;
> n->size = size;
>
> --
> 2.17.1