@@ -129,18 +129,3 @@ unsigned char *alloc_buffer(size_t buf_size, bool memflush)
return buf;
}
-
-int run_fill_buf(size_t buf_size, bool memflush)
-{
- unsigned char *buf;
-
- buf = alloc_buffer(buf_size, memflush);
- if (!buf)
- return -1;
-
- fill_cache_read(buf, buf_size, false);
-
- free(buf);
-
- return 0;
-}
@@ -169,7 +169,6 @@ int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
unsigned char *alloc_buffer(size_t buf_size, bool memflush);
void mem_flush(unsigned char *buf, size_t buf_size);
void fill_cache_read(unsigned char *buf, size_t buf_size, bool once);
-int run_fill_buf(size_t buf_size, bool memflush);
int initialize_read_mem_bw_imc(void);
int measure_read_mem_bw(const struct user_params *uparams,
struct resctrl_val_param *param, pid_t bm_pid);
@@ -373,7 +373,7 @@ static int get_mem_bw_resctrl(FILE *fp, unsigned long *mbm_total)
return 0;
}
-static pid_t bm_pid, ppid;
+static pid_t bm_pid;
void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
{
@@ -431,13 +431,6 @@ void signal_handler_unregister(void)
}
}
-static void parent_exit(pid_t ppid)
-{
- kill(ppid, SIGKILL);
- umount_resctrlfs();
- exit(EXIT_FAILURE);
-}
-
/*
* print_results_bw: the memory bandwidth results are stored in a file
* @filename: file that stores the results
@@ -535,52 +528,6 @@ int measure_read_mem_bw(const struct user_params *uparams,
return ret;
}
-struct benchmark_info {
- const struct user_params *uparams;
- struct resctrl_val_param *param;
-};
-
-/*
- * run_benchmark - Run a specified benchmark or fill_buf (default benchmark)
- * in specified signal. Direct benchmark stdio to /dev/null.
- * @signum: signal number
- * @info: signal info
- * @ucontext: user context in signal handling
- */
-static void run_benchmark(int signum, siginfo_t *info, void *ucontext)
-{
- struct benchmark_info *benchmark_info = info->si_ptr;
- const struct user_params *uparams = benchmark_info->uparams;
- struct resctrl_val_param *param = benchmark_info->param;
- FILE *fp;
- int ret;
-
- /*
- * Direct stdio of child to /dev/null, so that only parent writes to
- * stdio (console)
- */
- fp = freopen("/dev/null", "w", stdout);
- if (!fp) {
- ksft_perror("Unable to direct benchmark status to /dev/null");
- parent_exit(ppid);
- }
-
- if (param->fill_buf) {
- if (run_fill_buf(param->fill_buf->buf_size,
- param->fill_buf->memflush))
- fprintf(stderr, "Error in running fill buffer\n");
- } else if (uparams->benchmark_cmd[0]) {
- /* Execute specified benchmark */
- ret = execvp(uparams->benchmark_cmd[0], (char **)uparams->benchmark_cmd);
- if (ret)
- ksft_perror("execvp");
- }
-
- fclose(stdout);
- ksft_print_msg("Unable to run specified benchmark\n");
- parent_exit(ppid);
-}
-
/*
* resctrl_val: execute benchmark and measure memory bandwidth on
* the benchmark
@@ -594,12 +541,11 @@ int resctrl_val(const struct resctrl_test *test,
const struct user_params *uparams,
struct resctrl_val_param *param)
{
- struct benchmark_info benchmark_info;
- struct sigaction sigact;
- int ret = 0, pipefd[2];
- char pipe_message = 0;
- union sigval value;
+ unsigned char *buf = NULL;
+ cpu_set_t old_affinity;
int domain_id;
+ int ret = 0;
+ pid_t ppid;
if (strcmp(param->filename, "") == 0)
sprintf(param->filename, "stdio");
@@ -610,108 +556,65 @@ int resctrl_val(const struct resctrl_test *test,
return ret;
}
- benchmark_info.uparams = uparams;
- benchmark_info.param = param;
-
- /*
- * If benchmark wasn't successfully started by child, then child should
- * kill parent, so save parent's pid
- */
ppid = getpid();
- if (pipe(pipefd)) {
- ksft_perror("Unable to create pipe");
+ /* Taskset test to specified CPU. */
+ ret = taskset_benchmark(ppid, uparams->cpu, &old_affinity);
+ if (ret)
+ return ret;
+
+ /* Write test to specified control & monitoring group in resctrl FS. */
+ ret = write_bm_pid_to_resctrl(ppid, param->ctrlgrp, param->mongrp);
+ if (ret)
+ goto reset_affinity;
- return -1;
+ if (param->init) {
+ ret = param->init(param, domain_id);
+ if (ret)
+ goto reset_affinity;
}
/*
- * Fork to start benchmark, save child's pid so that it can be killed
- * when needed
+ * If not running user provided benchmark, run the default
+ * "fill_buf". First phase of "fill_buf" is to prepare the
+ * buffer that the benchmark will operate on. No measurements
+ * are needed during this phase and prepared memory will be
+ * passed to next part of benchmark via copy-on-write thus
+ * no impact on the benchmark that relies on reading from
+ * memory only.
*/
+ if (param->fill_buf) {
+ buf = alloc_buffer(param->fill_buf->buf_size,
+ param->fill_buf->memflush);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto reset_affinity;
+ }
+ }
+
fflush(stdout);
bm_pid = fork();
if (bm_pid == -1) {
+ ret = -errno;
ksft_perror("Unable to fork");
-
- return -1;
+ goto free_buf;
}
+ /*
+ * What needs to be measured runs in separate process until
+ * terminated.
+ */
if (bm_pid == 0) {
- /*
- * Mask all signals except SIGUSR1, parent uses SIGUSR1 to
- * start benchmark
- */
- sigfillset(&sigact.sa_mask);
- sigdelset(&sigact.sa_mask, SIGUSR1);
-
- sigact.sa_sigaction = run_benchmark;
- sigact.sa_flags = SA_SIGINFO;
-
- /* Register for "SIGUSR1" signal from parent */
- if (sigaction(SIGUSR1, &sigact, NULL)) {
- ksft_perror("Can't register child for signal");
- parent_exit(ppid);
- }
-
- /* Tell parent that child is ready */
- close(pipefd[0]);
- pipe_message = 1;
- if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
- sizeof(pipe_message)) {
- ksft_perror("Failed signaling parent process");
- close(pipefd[1]);
- return -1;
- }
- close(pipefd[1]);
-
- /* Suspend child until delivery of "SIGUSR1" from parent */
- sigsuspend(&sigact.sa_mask);
-
- ksft_perror("Child is done");
- parent_exit(ppid);
+ if (param->fill_buf)
+ fill_cache_read(buf, param->fill_buf->buf_size, false);
+ else if (uparams->benchmark_cmd[0])
+ execvp(uparams->benchmark_cmd[0], (char **)uparams->benchmark_cmd);
+ exit(EXIT_SUCCESS);
}
ksft_print_msg("Benchmark PID: %d\n", (int)bm_pid);
- value.sival_ptr = (void *)&benchmark_info;
-
- /* Taskset benchmark to specified cpu */
- ret = taskset_benchmark(bm_pid, uparams->cpu, NULL);
- if (ret)
- goto out;
-
- /* Write benchmark to specified control&monitoring grp in resctrl FS */
- ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp);
- if (ret)
- goto out;
-
- if (param->init) {
- ret = param->init(param, domain_id);
- if (ret)
- goto out;
- }
-
- /* Parent waits for child to be ready. */
- close(pipefd[1]);
- while (pipe_message != 1) {
- if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) <
- sizeof(pipe_message)) {
- ksft_perror("Failed reading message from child process");
- close(pipefd[0]);
- goto out;
- }
- }
- close(pipefd[0]);
-
- /* Signal child to start benchmark */
- if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
- ksft_perror("sigqueue SIGUSR1 to child");
- ret = -1;
- goto out;
- }
-
- /* Give benchmark enough time to fully run */
+ /* Give benchmark enough time to fully run. */
sleep(1);
/* Test runs until the callback setup() tells the test to stop. */
@@ -729,8 +632,10 @@ int resctrl_val(const struct resctrl_test *test,
break;
}
-out:
kill(bm_pid, SIGKILL);
-
+free_buf:
+ free(buf);
+reset_affinity:
+ taskset_restore(ppid, &old_affinity);
return ret;
}