Simplify trace_event_save_hist() and set_comm_cgroup() by computing string lengths once and storing them in local variables, rather than calling strlen() multiple times on the same unchanged strings. This makes the code clearer by eliminating redundant function calls and improving readability.
In trace_event_save_hist(), the write loop previously called strlen() on the hist buffer twice per iteration for both the size calculation and loop condition. Store the length in hist_len before entering the loop. In set_comm_cgroup(), strlen() was called on cgroup_path up to three times in succession. Store the result in cg_path_len to use in both the offset calculation and size parameter for subsequent append operations. This simplification makes the code easier to read and maintain without changing program behavior. Signed-off-by: Wander Lairson Costa <[email protected]> --- tools/tracing/rtla/src/trace.c | 6 ++++-- tools/tracing/rtla/src/utils.c | 11 +++++++---- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c index 092fcab77dc4c..223ab97e50aed 100644 --- a/tools/tracing/rtla/src/trace.c +++ b/tools/tracing/rtla/src/trace.c @@ -346,6 +346,7 @@ static void trace_event_save_hist(struct trace_instance *instance, mode_t mode = 0644; char path[MAX_PATH]; char *hist; + size_t hist_len; if (!tevent) return; @@ -376,9 +377,10 @@ static void trace_event_save_hist(struct trace_instance *instance, } index = 0; + hist_len = strlen(hist); do { - index += write(out_fd, &hist[index], strlen(hist) - index); - } while (index < strlen(hist)); + index += write(out_fd, &hist[index], hist_len - index); + } while (index < hist_len); free(hist); out_close: diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c index 4093030e446ab..aee7f02b1e9b4 100644 --- a/tools/tracing/rtla/src/utils.c +++ b/tools/tracing/rtla/src/utils.c @@ -870,6 +870,7 @@ int set_comm_cgroup(const char *comm_prefix, const char *cgroup) DIR *procfs; int retval; int cg_fd; + size_t cg_path_len; if (strlen(comm_prefix) >= MAX_PATH) { err_msg("Command prefix is too long: %d < strlen(%s)\n", @@ -883,16 +884,18 @@ int set_comm_cgroup(const char *comm_prefix, const char *cgroup) return 0; } + cg_path_len = strlen(cgroup_path); + if (!cgroup) { - retval = get_self_cgroup(&cgroup_path[strlen(cgroup_path)], - sizeof(cgroup_path) - strlen(cgroup_path)); + retval = get_self_cgroup(&cgroup_path[cg_path_len], + sizeof(cgroup_path) - cg_path_len); if (!retval) { err_msg("Did not find self cgroup\n"); return 0; } } else { - snprintf(&cgroup_path[strlen(cgroup_path)], - sizeof(cgroup_path) - strlen(cgroup_path), "%s/", cgroup); + snprintf(&cgroup_path[cg_path_len], + sizeof(cgroup_path) - cg_path_len, "%s/", cgroup); } snprintf(cgroup_procs, MAX_PATH, "%s/cgroup.procs", cgroup_path); -- 2.52.0
