Commit 3aff5146 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Shuah Khan
Browse files

selftests/resctrl: Extend signal handler coverage to unmount on receiving signal 



Unmounting resctrl FS has been moved into the per test functions in
resctrl_tests.c by commit caddc0fb ("selftests/resctrl: Move
resctrl FS mount/umount to higher level"). In case a signal (SIGINT,
SIGTERM, or SIGHUP) is received, the running selftest is aborted by
ctrlc_handler() which then unmounts resctrl fs before exiting. The
current section between signal_handler_register() and
signal_handler_unregister(), however, does not cover the entire
duration when resctrl FS is mounted.

Move signal_handler_register() and signal_handler_unregister() calls
from per test files into resctrl_tests.c to properly unmount resctrl
fs. In order to not add signal_handler_register()/unregister() n times,
create helpers test_prepare() and test_cleanup().

Do not call ksft_exit_fail_msg() in test_prepare() but only in the per
test function to keep the control flow cleaner without adding calls to
exit() deep into the call chain.

Adjust child process kill() call in ctrlc_handler() to only be invoked
if the child was already forked.

Fixes: caddc0fb ("selftests/resctrl: Move resctrl FS mount/umount to higher level")
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent beb7f471

tools/testing/selftests/resctrl/cat_test.c

+0 −8
Original line number Diff line number Diff line
@@ -167,12 +167,6 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type) 
		strcpy(param.filename, RESULT_FILE_NAME1);

		param.num_of_runs = 0;

		param.cpu_no = sibling_cpu_no;

	} else {

		ret = signal_handler_register();

		if (ret) {

			kill(bm_pid, SIGKILL);

			goto out;

		}

	}



	remove(param.filename);
@@ -209,10 +203,8 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type) 
		}

		close(pipefd[0]);

		kill(bm_pid, SIGKILL);

		signal_handler_unregister();

	}



out:

	cat_test_cleanup();



	return ret;

tools/testing/selftests/resctrl/resctrl_tests.c

+45 −24
Original line number Diff line number Diff line
@@ -67,21 +67,45 @@ void tests_cleanup(void) 
	cat_test_cleanup();

}



static void run_mbm_test(const char * const *benchmark_cmd, int cpu_no)

static int test_prepare(void)

{

	int res;



	ksft_print_msg("Starting MBM BW change ...\n");

	res = signal_handler_register();

	if (res) {

		ksft_print_msg("Failed to register signal handler\n");

		return res;

	}



	res = mount_resctrlfs();

	if (res) {

		ksft_exit_fail_msg("Failed to mount resctrl FS\n");

		signal_handler_unregister();

		ksft_print_msg("Failed to mount resctrl FS\n");

		return res;

	}

	return 0;

}



static void test_cleanup(void)

{

	umount_resctrlfs();

	signal_handler_unregister();

}



static void run_mbm_test(const char * const *benchmark_cmd, int cpu_no)

{

	int res;



	ksft_print_msg("Starting MBM BW change ...\n");



	if (test_prepare()) {

		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");

		return;

	}



	if (!validate_resctrl_feature_request(MBM_STR) || (get_vendor() != ARCH_INTEL)) {

		ksft_test_result_skip("Hardware does not support MBM or MBM is disabled\n");

		goto umount;

		goto cleanup;

	}



	res = mbm_bw_change(cpu_no, benchmark_cmd);
@@ -89,8 +113,8 @@ static void run_mbm_test(const char * const *benchmark_cmd, int cpu_no) 
	if ((get_vendor() == ARCH_INTEL) && res)

		ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");



umount:

	umount_resctrlfs();

cleanup:

	test_cleanup();

}



static void run_mba_test(const char * const *benchmark_cmd, int cpu_no)
@@ -99,22 +123,21 @@ static void run_mba_test(const char * const *benchmark_cmd, int cpu_no) 


	ksft_print_msg("Starting MBA Schemata change ...\n");



	res = mount_resctrlfs();

	if (res) {

		ksft_exit_fail_msg("Failed to mount resctrl FS\n");

	if (test_prepare()) {

		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");

		return;

	}



	if (!validate_resctrl_feature_request(MBA_STR) || (get_vendor() != ARCH_INTEL)) {

		ksft_test_result_skip("Hardware does not support MBA or MBA is disabled\n");

		goto umount;

		goto cleanup;

	}



	res = mba_schemata_change(cpu_no, benchmark_cmd);

	ksft_test_result(!res, "MBA: schemata change\n");



umount:

	umount_resctrlfs();

cleanup:

	test_cleanup();

}



static void run_cmt_test(const char * const *benchmark_cmd, int cpu_no)
@@ -123,15 +146,14 @@ static void run_cmt_test(const char * const *benchmark_cmd, int cpu_no) 


	ksft_print_msg("Starting CMT test ...\n");



	res = mount_resctrlfs();

	if (res) {

		ksft_exit_fail_msg("Failed to mount resctrl FS\n");

	if (test_prepare()) {

		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");

		return;

	}



	if (!validate_resctrl_feature_request(CMT_STR)) {

		ksft_test_result_skip("Hardware does not support CMT or CMT is disabled\n");

		goto umount;

		goto cleanup;

	}



	res = cmt_resctrl_val(cpu_no, 5, benchmark_cmd);
@@ -139,8 +161,8 @@ static void run_cmt_test(const char * const *benchmark_cmd, int cpu_no) 
	if ((get_vendor() == ARCH_INTEL) && res)

		ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");



umount:

	umount_resctrlfs();

cleanup:

	test_cleanup();

}



static void run_cat_test(int cpu_no, int no_of_bits)
@@ -149,22 +171,21 @@ static void run_cat_test(int cpu_no, int no_of_bits) 


	ksft_print_msg("Starting CAT test ...\n");



	res = mount_resctrlfs();

	if (res) {

		ksft_exit_fail_msg("Failed to mount resctrl FS\n");

	if (test_prepare()) {

		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");

		return;

	}



	if (!validate_resctrl_feature_request(CAT_STR)) {

		ksft_test_result_skip("Hardware does not support CAT or CAT is disabled\n");

		goto umount;

		goto cleanup;

	}



	res = cat_perf_miss_val(cpu_no, no_of_bits, "L3");

	ksft_test_result(!res, "CAT: test\n");



umount:

	umount_resctrlfs();

cleanup:

	test_cleanup();

}



int main(int argc, char **argv)

tools/testing/selftests/resctrl/resctrl_val.c

+10 −12
Original line number Diff line number Diff line
@@ -468,6 +468,8 @@ pid_t bm_pid, ppid; 


void ctrlc_handler(int signum, siginfo_t *info, void *ptr)

{

	/* Only kill child after bm_pid is set after fork() */

	if (bm_pid)

		kill(bm_pid, SIGKILL);

	umount_resctrlfs();

	tests_cleanup();
@@ -485,6 +487,8 @@ int signal_handler_register(void) 
	struct sigaction sigact = {};

	int ret = 0;



	bm_pid = 0;



	sigact.sa_sigaction = ctrlc_handler;

	sigemptyset(&sigact.sa_mask);

	sigact.sa_flags = SA_SIGINFO;
@@ -706,10 +710,6 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par 


	ksft_print_msg("Benchmark PID: %d\n", bm_pid);



	ret = signal_handler_register();

	if (ret)

		goto out;



	/*

	 * The cast removes constness but nothing mutates benchmark_cmd within

	 * the context of this process. At the receiving process, it becomes
@@ -721,19 +721,19 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par 
	/* Taskset benchmark to specified cpu */

	ret = taskset_benchmark(bm_pid, param->cpu_no);

	if (ret)

		goto unregister;

		goto out;



	/* Write benchmark to specified control&monitoring grp in resctrl FS */

	ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,

				      resctrl_val);

	if (ret)

		goto unregister;

		goto out;



	if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) ||

	    !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) {

		ret = initialize_mem_bw_imc();

		if (ret)

			goto unregister;

			goto out;



		initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,

					  param->cpu_no, resctrl_val);
@@ -748,7 +748,7 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par 
		    sizeof(pipe_message)) {

			perror("# failed reading message from child process");

			close(pipefd[0]);

			goto unregister;

			goto out;

		}

	}

	close(pipefd[0]);
@@ -757,7 +757,7 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par 
	if (sigqueue(bm_pid, SIGUSR1, value) == -1) {

		perror("# sigqueue SIGUSR1 to child");

		ret = errno;

		goto unregister;

		goto out;

	}



	/* Give benchmark enough time to fully run */
@@ -786,8 +786,6 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par 
		}

	}



unregister:

	signal_handler_unregister();

out:

	kill(bm_pid, SIGKILL);