linux-kernel - [PATCH 1/2] perf: drop unneeded bitmap

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Date:   Sat, 23 Jun 2018 10:35:01 +0300
From:   Yury Norov <ynorov@...iumnetworks.com>
To:     Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Kate Stewart <kstewart@...uxfoundation.org>,
        Matthew Wilcox <willy@...radead.org>,
        Philippe Ombredanne <pombredanne@...b.com>,
        David Ahern <dsahern@...il.com>,
        David Carrillo-Cisneros <davidcc@...gle.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Jin Yao <yao.jin@...ux.intel.com>, linux-kernel@...r.kernel.org
Cc:     Yury Norov <ynorov@...iumnetworks.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Mike Snitzer <snitzer@...hat.com>
Subject: [PATCH 1/2] perf: drop unneeded bitmap_zero() in util/header.c

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@...iumnetworks.com>
---
 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