Re: [PATCH v2 2/3] selftests/resctrl: Simplify cleanup in ctrl-c handler

[Ilpo Järvinen]

On Thu, 22 Feb 2024, Maciej Wieczor-Retman wrote:

> Ctrl-c handler isn't aware of what test is currently running. Because of
> that it executes all cleanups even if they aren't necessary. Since the
> ctrl-c handler uses the sa_sigaction system no parameters can be passed
> to it as function arguments.
> 
> Add a global variable to make ctrl-c handler aware of the currently run
> test and only execute the correct cleanup callback.
> 
> Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>
> ---
> Changelog v2:
> - Remove tests_cleanup() from resctrl.h.
> - Make current_test a const pointer only inside resctrl_val.c. (Ilpo)
> 
>  tools/testing/selftests/resctrl/resctrl.h       |  3 +--
>  tools/testing/selftests/resctrl/resctrl_tests.c | 14 +++-----------
>  tools/testing/selftests/resctrl/resctrl_val.c   |  6 ++++--
>  3 files changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index 0f49df4961ea..826783b29c9d 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -153,7 +153,6 @@ int resctrl_val(const struct resctrl_test *test,
>  		const struct user_params *uparams,
>  		const char * const *benchmark_cmd,
>  		struct resctrl_val_param *param);
> -void tests_cleanup(void);
>  void mbm_test_cleanup(void);
>  void mba_test_cleanup(void);
>  unsigned long create_bit_mask(unsigned int start, unsigned int len);
> @@ -162,7 +161,7 @@ int get_full_cbm(const char *cache_type, unsigned long *mask);
>  int get_mask_no_shareable(const char *cache_type, unsigned long *mask);
>  int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size);
>  void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
> -int signal_handler_register(void);
> +int signal_handler_register(const struct resctrl_test *test);
>  void signal_handler_unregister(void);
>  void cat_test_cleanup(void);
>  unsigned int count_bits(unsigned long n);
> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
> index 75fc49ba3efb..161f5365b4f0 100644
> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
> @@ -75,19 +75,11 @@ static void cmd_help(void)
>  	printf("\t-h: help\n");
>  }
>  
> -void tests_cleanup(void)
> -{
> -	mbm_test_cleanup();
> -	mba_test_cleanup();
> -	cmt_test_cleanup();
> -	cat_test_cleanup();
> -}
> -
> -static int test_prepare(void)
> +static int test_prepare(const struct resctrl_test *test)
>  {
>  	int res;
>  
> -	res = signal_handler_register();
> +	res = signal_handler_register(test);
>  	if (res) {
>  		ksft_print_msg("Failed to register signal handler\n");
>  		return res;
> @@ -130,7 +122,7 @@ static void run_single_test(const struct resctrl_test *test, const struct user_p
>  
>  	ksft_print_msg("Starting %s test ...\n", test->name);
>  
> -	if (test_prepare()) {
> +	if (test_prepare(test)) {
>  		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");
>  		return;
>  	}
> diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
> index 5a49f07a6c85..d572815436f3 100644
> --- a/tools/testing/selftests/resctrl/resctrl_val.c
> +++ b/tools/testing/selftests/resctrl/resctrl_val.c
> @@ -62,6 +62,7 @@ struct imc_counter_config {
>  static char mbm_total_path[1024];
>  static int imcs;
>  static struct imc_counter_config imc_counters_config[MAX_IMCS][2];
> +const struct resctrl_test *current_test;

static const struct

>  void membw_initialize_perf_event_attr(int i, int j)
>  {
> @@ -472,7 +473,7 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
>  	if (bm_pid)
>  		kill(bm_pid, SIGKILL);
>  	umount_resctrlfs();
> -	tests_cleanup();
> +	current_test->cleanup();

These calls should have if (current_test->cleanup()) guard. Isn't the 
non-contiguous already test w/o the cleanup function?

Other than those two, this looked okay.

-- 
 i.