On 10/31/18 4:02 PM, Fenghua Yu wrote:
> From: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com>
>
> The callback starts a child process and puts the child pid in created
> resctrl group with specified memory bandwidth in schemata. The child
> starts running benchmark.
>
> Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prak...@intel.com>
> Signed-off-by: Arshiya Hayatkhan Pathan <arshiya.hayatkhan.pat...@intel.com>
> Signed-off-by: Fenghua Yu <fenghua...@intel.com>
> ---
> tools/testing/selftests/resctrl/membw.c | 272
> ++++++++++++++++++++++++++++++
> tools/testing/selftests/resctrl/resctrl.h | 27 +++
> 2 files changed, 299 insertions(+)
>
> diff --git a/tools/testing/selftests/resctrl/membw.c
> b/tools/testing/selftests/resctrl/membw.c
> index 3146cf8b7468..75a20de0ff71 100644
> --- a/tools/testing/selftests/resctrl/membw.c
> +++ b/tools/testing/selftests/resctrl/membw.c
> @@ -11,6 +11,7 @@
> */
> #include "resctrl.h"
>
> +#define MB (1024 * 1024)
> #define UNCORE_IMC "uncore_imc"
> #define READ_FILE_NAME "events/cas_count_read"
> #define WRITE_FILE_NAME "events/cas_count_write"
> @@ -429,3 +430,274 @@ static unsigned long get_mem_bw_resctrl(void)
>
> return mbm_total;
> }
> +
> +pid_t bm_pid, ppid;
> +
> +static void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
> +{
> + kill(bm_pid, SIGKILL);
> + printf("Ending\n\n");
> +
> + exit(EXIT_SUCCESS);
> +}
> +
> +/*
> + * print_results_bw: the memory bandwidth results are stored in a file
> + * @filename: file that stores the results
> + * @bm_pid: child pid that runs benchmark
> + * @bw_imc: perf imc counter value
> + * @bw_resc: memory bandwidth value
> + *
> + * Return: 0 on success. non-zero on failure.
> + */
> +static int print_results_bw(char *filename, int bm_pid, float bw_imc,
> + unsigned long bw_resc)
> +{
> + unsigned long diff = labs(bw_imc - bw_resc);
> + FILE *fp;
> +
> + if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
> + printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc);
> + printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff);
> + } else {
> + fp = fopen(filename, "a");
> + if (!fp) {
> + perror("Cannot open results file");
> +
> + return errno;
> + }
> + if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu
> \t Difference: %lu\n",
> + bm_pid, bw_imc, bw_resc, diff) <= 0) {
> + fclose(fp);
> + perror("Could not log results.");
> +
> + return errno;
> + }
> + fclose(fp);
> + }
> +
> + return 0;
> +}
> +
> +static int
> +measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
> +{
> + unsigned long bw_imc, bw_resc, bw_resc_end;
> + int ret;
> +
> + /*
> + * Measure memory bandwidth from resctrl and from
> + * another source which is perf imc value or could
> + * be something else if perf imc event is not available.
> + * Compare the two values to validate resctrl value.
> + * It takes 1sec to measure the data.
> + */
> + bw_imc = get_mem_bw_imc(param->cpu_no, param->bw_report);
> + if (bw_imc < 0)
I think this condition should be "<=". If the value is zero, it should exit.
> + return bw_imc;
> +
> + bw_resc_end = get_mem_bw_resctrl();
> + if (bw_resc_end < 0)
I am not very sure about this. Please check if it should be "<=" 0.
> + return bw_resc_end;
> +
> + bw_resc = (bw_resc_end - *bw_resc_start) / MB;
> + ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);
> + if (ret)
> + return ret;
> +
> + *bw_resc_start = bw_resc_end;
> +
> + return 0;
> +}
> +
> +/*
> + * membw_val: execute benchmark and measure memory bandwidth
> on
> + * the benchmark
> + * @benchmark_cmd: benchmark command and its arguments
> + * @param: parameters passed to membw_val()
> + *
> + * Return: 0 on success. non-zero on failure.
> + */
> +int membw_val(char **benchmark_cmd, struct resctrl_val_param *param)
> +{
> + int ret = 0, pipefd[2], pipe_message = 0;
> + char *resctrl_val = param->resctrl_val;
> + unsigned long bw_resc_start = 0;
> + struct sigaction sigact;
> + union sigval value;
> + FILE *fp;
> +
> + if (strcmp(param->filename, "") == 0)
> + sprintf(param->filename, "stdio");
> +
> + if (strcmp(param->bw_report, "") == 0)
> + param->bw_report = "total";
> +
> + ret = validate_resctrl_feature_request(resctrl_val);
> + if (ret)
> + return ret;
> +
> + if ((strcmp(resctrl_val, "mba")) == 0 ||
> + (strcmp(resctrl_val, "mbm")) == 0) {
> + ret = validate_bw_report_request(param->bw_report);
> + if (ret)
> + return ret;
> + }
> +
> + ret = remount_resctrlfs(param->mum_resctrlfs);
> + if (ret)
> + return ret;
> +
> + /*
> + * If benchmark wasn't successfully started by child, then child should
> + * kill parent, so save parent's pid
> + */
> + ppid = getpid();
> +
> + /* File based synchronization between parent and child */
> + fp = fopen("sig", "w");
> + if (!fp) {
> + perror("Failed to open sig file");
> +
> + return -1;
> + }
> + if (fprintf(fp, "%d\n", 0) <= 0) {
> + perror("Unable to establish sync bw parent & child");
> + fclose(fp);
> +
> + return -1;
> + }
> + fclose(fp);
> +
> + if (pipe(pipefd)) {
> + perror("Unable to create pipe");
> +
> + return -1;
> + }
> +
> + /*
> + * Fork to start benchmark, save child's pid so that it can be killed
> + * when needed
> + */
> + bm_pid = fork();
> + if (bm_pid == -1) {
> + perror("Unable to fork");
> +
> + return -1;
> + }
> +
> + 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))
> + PARENT_EXIT("Can't register child for signal");
> +
> + /* Tell parent that child is ready */
> + close(pipefd[0]);
> + pipe_message = 1;
> + write(pipefd[1], &pipe_message, sizeof(pipe_message));
> + close(pipefd[1]);
> +
> + /* Suspend child until delivery of "SIGUSR1" from parent */
> + sigsuspend(&sigact.sa_mask);
> +
> + PARENT_EXIT("Child is done");
> + }
> +
> + printf("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(SIGHUP, &sigact, NULL)) {
> + perror("Can't register parent for CTRL-C handler");
> + ret = errno;
> + goto out;
> + }
> +
> + value.sival_ptr = benchmark_cmd;
> +
> + /* Taskset benchmark to specified cpu */
> + ret = taskset_benchmark(bm_pid, param->cpu_no);
> + 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,
> + resctrl_val);
> + if (ret)
> + goto out;
> +
> + if ((strcmp(resctrl_val, "mbm") == 0) ||
> + (strcmp(resctrl_val, "mba") == 0)) {
> + ret = initialize_mem_bw_imc();
> + if (ret)
> + goto out;
> +
> + initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
> + param->cpu_no, resctrl_val);
> + }
> +
> + /* Parent waits for child to be ready. */
> + close(pipefd[1]);
> + while (pipe_message != 1)
> + read(pipefd[0], &pipe_message, sizeof(pipe_message));
> + close(pipefd[0]);
> +
> + /* Signal child to start benchmark */
> + if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
> + perror("Unable to signal child to start execution");
> + ret = errno;
> + goto out;
> + }
> +
> + /* Give benchmark enough time to fully run */
> + sleep(1);
> +
> + /* Test runs until the callback setup() tells the test to stop. */
> + while (1) {
> + if (strcmp(resctrl_val, "mbm") == 0) {
> + ret = param->setup(1, param);
> + if (ret) {
> + ret = 0;
> + break;
> + }
> +
> + ret = measure_vals(param, &bw_resc_start);
> + if (ret)
> + break;
> + } else if ((strcmp(resctrl_val, "mba") == 0)) {
> + ret = param->setup(1, param);
> + if (ret) {
> + ret = 0;
> + break;
> + }
> +
> + ret = measure_vals(param, &bw_resc_start);
> + if (ret)
> + break;
> + } else {
> + break;
> + }
> + }
> +
> +out:
> + kill(bm_pid, SIGKILL);
> + umount_resctrlfs();
> +
> + return ret;
> +}
> diff --git a/tools/testing/selftests/resctrl/resctrl.h
> b/tools/testing/selftests/resctrl/resctrl.h
> index 01822f6258af..9820af253d4d 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -3,6 +3,7 @@
> #ifndef RESCTRL_H
> #define RESCTRL_H
> #include <stdio.h>
> +#include <stdarg.h>
> #include <errno.h>
> #include <sched.h>
> #include <stdlib.h>
> @@ -28,9 +29,34 @@
> exit(EXIT_FAILURE); \
> } while (0)
>
> +/*
> + * resctrl_val_param: resctrl test parameters
> + * @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc)
> + * @ctrlgrp: Name of the control monitor group (con_mon grp)
> + * @mongrp: Name of the monitor group (mon grp)
> + * @cpu_no: CPU number to which the benchmark would be binded
> + * @span: Memory bytes accessed in each benchmark iteration
> + * @mum_resctrlfs: Should the resctrl FS be remounted?
> + * @filename: Name of file to which the o/p should be written
> + * @bw_report: Bandwidth report type (reads vs writes)
> + * @setup: Call back function to setup test environment
> + */
> +struct resctrl_val_param {
> + char *resctrl_val;
> + char ctrlgrp[64];
> + char mongrp[64];
> + int cpu_no;
> + int span;
> + int mum_resctrlfs;
> + char filename[64];
> + char *bw_report;
> + int (*setup)(int num, ...);
> +};
> +
> pid_t bm_pid, ppid;
>
> int remount_resctrlfs(bool mum_resctrlfs);
> +int umount_resctrlfs(void);
> char get_sock_num(int cpu_no);
> int validate_bw_report_request(char *bw_report);
> int validate_resctrl_feature_request(char *resctrl_val);
> @@ -43,5 +69,6 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp,
> char *mongrp,
> int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
> int group_fd, unsigned long flags);
> int run_fill_buf(int span, int malloc_and_init_memory, int memflush, int op);
> +int membw_val(char **benchmark_cmd, struct resctrl_val_param *param);
>
> #endif /* RESCTRL_H */
>
