[PATCH v7 5/6] selftests/resctrl: Commonize the signal handler register/unregister for all tests
From: Shaopeng Tan
Date: Mon Feb 13 2023 - 01:28:57 EST
After creating a child process with fork() in CAT test, if a signal such
as SIGINT is received, the parent process will be terminated immediately,
and therefor the child process will not be killed and also resctrlfs is
not unmounted.
There is a signal handler registered in CMT/MBM/MBA tests, which kills
child process, unmount resctrlfs, cleanups result files, etc., if a
signal such as SIGINT is received.
Commonize the signal handler registered for CMT/MBM/MBA tests and
reuse it in CAT.
To reuse the signal handler to kill child process use global bm_pid
instead of local bm_pid.
Also, since the MBA/MBA/CMT/CAT are run in order, unregister the signal
handler at the end of each test so that the signal handler cannot be
inherited by other tests.
Signed-off-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
---
tools/testing/selftests/resctrl/cat_test.c | 9 ++-
tools/testing/selftests/resctrl/fill_buf.c | 14 ----
tools/testing/selftests/resctrl/resctrl.h | 2 +
tools/testing/selftests/resctrl/resctrl_val.c | 66 ++++++++++++++-----
4 files changed, 58 insertions(+), 33 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 477b62dac546..0bdf0305a506 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -103,7 +103,6 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
unsigned long l_mask, l_mask_1;
int ret, pipefd[2], sibling_cpu_no;
char pipe_message;
- pid_t bm_pid;
cache_size = 0;
@@ -181,6 +180,12 @@ 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);
@@ -217,8 +222,10 @@ 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();
if (bm_pid)
umount_resctrlfs();
diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c
index 56ccbeae0638..322c6812e15c 100644
--- a/tools/testing/selftests/resctrl/fill_buf.c
+++ b/tools/testing/selftests/resctrl/fill_buf.c
@@ -33,14 +33,6 @@ static void sb(void)
#endif
}
-static void ctrl_handler(int signo)
-{
- free(startptr);
- printf("\nEnding\n");
- sb();
- exit(EXIT_SUCCESS);
-}
-
static void cl_flush(void *p)
{
#if defined(__i386) || defined(__x86_64)
@@ -198,12 +190,6 @@ int run_fill_buf(unsigned long span, int malloc_and_init_memory,
unsigned long long cache_size = span;
int ret;
- /* set up ctrl-c handler */
- if (signal(SIGINT, ctrl_handler) == SIG_ERR)
- printf("Failed to catch SIGINT!\n");
- if (signal(SIGHUP, ctrl_handler) == SIG_ERR)
- printf("Failed to catch SIGHUP!\n");
-
ret = fill_cache(cache_size, malloc_and_init_memory, memflush, op,
resctrl_val);
if (ret) {
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index f0ded31fb3c7..92b59d2f603d 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -107,6 +107,8 @@ void mba_test_cleanup(void);
int get_cbm_mask(char *cache_type, char *cbm_mask);
int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size);
void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
+int signal_handler_register(void);
+void signal_handler_unregister(void);
int cat_val(struct resctrl_val_param *param);
void cat_test_cleanup(void);
int cat_perf_miss_val(int cpu_no, int no_of_bits, char *cache_type);
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 6948843bf995..7c8d5c25e6da 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -476,6 +476,45 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
exit(EXIT_SUCCESS);
}
+/*
+ * Register CTRL-C handler for parent, as it has to kill
+ * child process before exiting.
+ */
+int signal_handler_register(void)
+{
+ struct sigaction sigact;
+ int ret = 0;
+
+ sigact.sa_sigaction = ctrlc_handler;
+ sigemptyset(&sigact.sa_mask);
+ sigact.sa_flags = SA_SIGINFO;
+ if (sigaction(SIGINT, &sigact, NULL) ||
+ sigaction(SIGTERM, &sigact, NULL) ||
+ sigaction(SIGHUP, &sigact, NULL)) {
+ perror("# sigaction");
+ ret = -1;
+ }
+ return ret;
+}
+
+/*
+ * Reset signal handler to SIG_DFL.
+ * Non-Value return because the caller should keep
+ * the error code of other path even if sigaction fails.
+ */
+void signal_handler_unregister(void)
+{
+ struct sigaction sigact;
+
+ sigact.sa_handler = SIG_DFL;
+ sigemptyset(&sigact.sa_mask);
+ if (sigaction(SIGINT, &sigact, NULL) ||
+ sigaction(SIGTERM, &sigact, NULL) ||
+ sigaction(SIGHUP, &sigact, NULL)) {
+ perror("# sigaction");
+ }
+}
+
/*
* print_results_bw: the memory bandwidth results are stored in a file
* @filename: file that stores the results
@@ -671,39 +710,28 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
ksft_print_msg("Benchmark PID: %d\n", bm_pid);
- /*
- * Register CTRL-C handler for parent, as it has to kill benchmark
- * before exiting
- */
- sigact.sa_sigaction = ctrlc_handler;
- sigemptyset(&sigact.sa_mask);
- sigact.sa_flags = SA_SIGINFO;
- if (sigaction(SIGINT, &sigact, NULL) ||
- sigaction(SIGTERM, &sigact, NULL) ||
- sigaction(SIGHUP, &sigact, NULL)) {
- perror("# sigaction");
- ret = errno;
+ ret = signal_handler_register();
+ if (ret)
goto out;
- }
value.sival_ptr = benchmark_cmd;
/* Taskset benchmark to specified cpu */
ret = taskset_benchmark(bm_pid, param->cpu_no);
if (ret)
- goto out;
+ goto unregister;
/* 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 out;
+ goto unregister;
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 out;
+ goto unregister;
initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
param->cpu_no, resctrl_val);
@@ -718,7 +746,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
sizeof(pipe_message)) {
perror("# failed reading message from child process");
close(pipefd[0]);
- goto out;
+ goto unregister;
}
}
close(pipefd[0]);
@@ -727,7 +755,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
perror("# sigqueue SIGUSR1 to child");
ret = errno;
- goto out;
+ goto unregister;
}
/* Give benchmark enough time to fully run */
@@ -761,6 +789,8 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
}
}
+unregister:
+ signal_handler_unregister();
out:
kill(bm_pid, SIGKILL);
umount_resctrlfs();
--
2.27.0