Hi Ilpo,
On 8/30/2023 1:59 AM, Ilpo Järvinen wrote:
On Tue, 29 Aug 2023, Reinette Chatre wrote:
This is a tricky one. If I understand correctly this goto target makes some assumptions about the state (no test plan created yet) and exit reason (it has to be skipped). A temporary variable is also thrown into the mix.
So in the end the symmetry proved to be not as simple as was depicted earlier but "tricky"... I tried to warn about this and it's why I wished to avoid the allocation entirely. Without allocation, there would have not been need for the temporary variable nor adjusting the control flow with that label.
hmmm ... I do not see why an allocation forces the use of a temporary variable and a change in control (more below).
Can this not be simplified by moving the snippet where benchmark_cmd[] is initialized to fill_buf to be just before the tests are run? Perhaps right before ksft_set_plan()?
So I throw a temporary variable into the mix (has_ben) to keep track when benchmark_cmd needs to be initialized to the default command? It doesn't play well with what I've in queue after this when user parameters are collected into a struct which is initialized to default value by a helper function before any argument processing. That is, initializing the parameters to defaults needs to be split before and after the parameter parsing code.
No new temporary variable is needed. Of course, I do not have insight into what is further down in your queue but based on this work I do think it can be simplified. Since code is easier to consider, the snippet below applies on top of this series and shows what I was proposing:
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c index ae9001ef7b0a..8033eabb9aa8 100644 --- a/tools/testing/selftests/resctrl/resctrl_tests.c +++ b/tools/testing/selftests/resctrl/resctrl_tests.c @@ -170,11 +170,10 @@ static void run_cat_test(int cpu_no, int no_of_bits) int main(int argc, char **argv) { bool mbm_test = true, mba_test = true, cmt_test = true; + const char *benchmark_cmd[BENCHMARK_ARGS] = {}; int c, cpu_no = 1, i, no_of_bits = 0; - const char *benchmark_cmd[BENCHMARK_ARGS]; char *span_str = NULL; bool cat_test = true; - char *skip_reason; int tests = 0; int ret;
@@ -247,17 +246,6 @@ int main(int argc, char **argv) } }
- /* If no benchmark is given by "-b" argument, use fill_buf. */ - benchmark_cmd[0] = "fill_buf"; - ret = asprintf(&span_str, "%u", DEFAULT_SPAN); - if (ret < 0) - ksft_exit_fail_msg("Out of memory!\n"); - benchmark_cmd[1] = span_str; - benchmark_cmd[2] = "1"; - benchmark_cmd[3] = "0"; - benchmark_cmd[4] = "false"; - benchmark_cmd[5] = NULL; - last_arg:
ksft_print_header(); @@ -267,23 +255,30 @@ int main(int argc, char **argv) * 1. We write to resctrl FS * 2. We execute perf commands */ - if (geteuid() != 0) { - skip_reason = "Not running as root. Skipping...\n"; - goto free_span; - } + if (geteuid() != 0) + return ksft_exit_skip("Not running as root. Skipping...\n");
- if (!check_resctrlfs_support()) { - skip_reason = "resctrl FS does not exist. Enable X86_CPU_RESCTRL config option.\n"; - goto free_span; - } + if (!check_resctrlfs_support()) + return ksft_exit_skip("resctrl FS does not exist. Enable X86_CPU_RESCTRL config option.\n");
- if (umount_resctrlfs()) { - skip_reason = "resctrl FS unmount failed.\n"; - goto free_span; - } + if (umount_resctrlfs()) + return ksft_exit_skip("resctrl FS unmount failed.\n");
filter_dmesg();
+ if (!benchmark_cmd[0]) { + /* If no benchmark is given by "-b" argument, use fill_buf. */ + benchmark_cmd[0] = "fill_buf"; + ret = asprintf(&span_str, "%u", DEFAULT_SPAN); + if (ret < 0) + ksft_exit_fail_msg("Out of memory!\n"); + benchmark_cmd[1] = span_str; + benchmark_cmd[2] = "1"; + benchmark_cmd[3] = "0"; + benchmark_cmd[4] = "false"; + benchmark_cmd[5] = NULL; + } + ksft_set_plan(tests ? : 4);
if (mbm_test) @@ -300,8 +295,4 @@ int main(int argc, char **argv)
free(span_str); ksft_finished(); - -free_span: - free(span_str); - return ksft_exit_skip(skip_reason); }