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SubjectRe: [PATCH] perf map: remove extra indirection from map__find()
On Fri, Nov 23, 2018 at 02:42:39AM -0800, Eric Saint-Etienne wrote:
> A double pointer is used in map__find() where a single pointer is enough
> because the function doesn't affect the rbtree and the rbtree is locked.
>
> Signed-off-by: Eric Saint-Etienne <eric.saint.etienne@oracle.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> ---
> tools/perf/util/map.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index 354e545..3dac766 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -846,19 +846,18 @@ void maps__remove(struct maps *maps, struct map *map)
>
> struct map *maps__find(struct maps *maps, u64 ip)
> {
> - struct rb_node **p, *parent = NULL;
> + struct rb_node *p;
> struct map *m;
>
> down_read(&maps->lock);
>
> - p = &maps->entries.rb_node;
> - while (*p != NULL) {
> - parent = *p;
> - m = rb_entry(parent, struct map, rb_node);
> + p = maps->entries.rb_node;
> + while (p != NULL) {
> + m = rb_entry(p, struct map, rb_node);
> if (ip < m->start)
> - p = &(*p)->rb_left;
> + p = p->rb_left;
> else if (ip >= m->end)
> - p = &(*p)->rb_right;
> + p = p->rb_right;
> else
> goto out;
> }
> --
> 1.8.3.1
>

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