# \[PATCH v3 5/9\] perf tools: avoid a malloc for array events - From: Ian Rogers \ - Date: 2019-10-24 19:02:29 - List: netdev - Page: https://ratatoskr.run/netdev/2019/10/5755246 - Thread: https://ratatoskr.run/netdev/2019/10/5753173/t.md ```text Use realloc rather than malloc+memcpy to possibly avoid a memory allocation when appending array elements. Signed-off-by: Ian Rogers --- tools/perf/util/parse-events.y | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y index 26cb65798522..545ab7cefc20 100644 --- a/tools/perf/util/parse-events.y +++ b/tools/perf/util/parse-events.y @@ -691,14 +691,12 @@ array_terms ',' array_term struct parse_events_array new_array; new_array.nr_ranges = $1.nr_ranges + $3.nr_ranges; - new_array.ranges = malloc(sizeof(new_array.ranges[0]) * - new_array.nr_ranges); + new_array.ranges = realloc($1.ranges, + sizeof(new_array.ranges[0]) * + new_array.nr_ranges); ABORT_ON(!new_array.ranges); - memcpy(&new_array.ranges[0], $1.ranges, - $1.nr_ranges * sizeof(new_array.ranges[0])); memcpy(&new_array.ranges[$1.nr_ranges], $3.ranges, $3.nr_ranges * sizeof(new_array.ranges[0])); - free($1.ranges); free($3.ranges); $$ = new_array; } -- 2.23.0.866.gb869b98d4c-goog ```