From feaaa8be0b1efce6e8fb4222654413246bdc30aa Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Wed, 3 Jul 2024 10:21:16 -0700 Subject: [PATCH] perf comm str: Avoid sort during insert The array is sorted, so just move the elements and insert in order. Fixes: 13ca628716c6 ("perf comm: Add reference count checking to 'struct comm_str'") Reported-by: Matt Fleming Signed-off-by: Ian Rogers Tested-by: Matt Fleming Cc: Steinar Gunderson Cc: Athira Rajeev Link: https://lore.kernel.org/r/20240703172117.810918-2-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/util/comm.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c index 233f2b6edf52..49b79cf0c5cc 100644 --- a/tools/perf/util/comm.c +++ b/tools/perf/util/comm.c @@ -86,14 +86,6 @@ static struct comm_str *comm_str__new(const char *str) return result; } -static int comm_str__cmp(const void *_lhs, const void *_rhs) -{ - const struct comm_str *lhs = *(const struct comm_str * const *)_lhs; - const struct comm_str *rhs = *(const struct comm_str * const *)_rhs; - - return strcmp(comm_str__str(lhs), comm_str__str(rhs)); -} - static int comm_str__search(const void *_key, const void *_member) { const char *key = _key; @@ -169,9 +161,24 @@ static struct comm_str *comm_strs__findnew(const char *str) } result = comm_str__new(str); if (result) { - comm_strs->strs[comm_strs->num_strs++] = result; - qsort(comm_strs->strs, comm_strs->num_strs, sizeof(struct comm_str *), - comm_str__cmp); + int low = 0, high = comm_strs->num_strs - 1; + int insert = comm_strs->num_strs; /* Default to inserting at the end. */ + + while (low <= high) { + int mid = low + (high - low) / 2; + int cmp = strcmp(comm_str__str(comm_strs->strs[mid]), str); + + if (cmp < 0) { + low = mid + 1; + } else { + high = mid - 1; + insert = mid; + } + } + memmove(&comm_strs->strs[insert + 1], &comm_strs->strs[insert], + (comm_strs->num_strs - insert) * sizeof(struct comm_str *)); + comm_strs->num_strs++; + comm_strs->strs[insert] = result; } } up_write(&comm_strs->lock);