selftests/resctrl: Add basic resctrl file system operations and data

The basic resctrl file system operations and data are added for future
usage by resctrl selftest tool.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
Sai Praneeth Prakhya 2020-01-16 13:32:35 -08:00 committed by Shuah Khan
parent 034c7678dd
commit 591a6e8588
3 changed files with 524 additions and 0 deletions

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CC = $(CROSS_COMPILE)gcc
CFLAGS = -g -Wall
SRCS=$(wildcard *.c)
OBJS=$(SRCS:.c=.o)
$(OBJS): $(SRCS)
$(CC) $(CFLAGS) -c $(SRCS)
.PHONY: clean
clean:
$(RM) $(OBJS)

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/* SPDX-License-Identifier: GPL-2.0 */
#define _GNU_SOURCE
#ifndef RESCTRL_H
#define RESCTRL_H
#include <stdio.h>
#include <errno.h>
#include <sched.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <dirent.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <asm/unistd.h>
#include <linux/perf_event.h>
#define RESCTRL_PATH "/sys/fs/resctrl"
#define PHYS_ID_PATH "/sys/devices/system/cpu/cpu"
#define PARENT_EXIT(err_msg) \
do { \
perror(err_msg); \
kill(ppid, SIGKILL); \
exit(EXIT_FAILURE); \
} while (0)
pid_t bm_pid, ppid;
int remount_resctrlfs(bool mum_resctrlfs);
int get_resource_id(int cpu_no, int *resource_id);
int validate_bw_report_request(char *bw_report);
bool validate_resctrl_feature_request(char *resctrl_val);
char *fgrep(FILE *inf, const char *str);
int taskset_benchmark(pid_t bm_pid, int cpu_no);
void run_benchmark(int signum, siginfo_t *info, void *ucontext);
int write_schemata(char *ctrlgrp, char *schemata, int cpu_no,
char *resctrl_val);
int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
char *resctrl_val);
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(unsigned long span, int malloc_and_init_memory, int memflush,
int op, char *resctrl_va);
#endif /* RESCTRL_H */

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// SPDX-License-Identifier: GPL-2.0
/*
* Basic resctrl file system operations
*
* Copyright (C) 2018 Intel Corporation
*
* Authors:
* Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
* Fenghua Yu <fenghua.yu@intel.com>
*/
#include "resctrl.h"
int tests_run;
static int find_resctrl_mount(char *buffer)
{
FILE *mounts;
char line[256], *fs, *mntpoint;
mounts = fopen("/proc/mounts", "r");
if (!mounts) {
perror("/proc/mounts");
return -ENXIO;
}
while (!feof(mounts)) {
if (!fgets(line, 256, mounts))
break;
fs = strtok(line, " \t");
if (!fs)
continue;
mntpoint = strtok(NULL, " \t");
if (!mntpoint)
continue;
fs = strtok(NULL, " \t");
if (!fs)
continue;
if (strcmp(fs, "resctrl"))
continue;
fclose(mounts);
if (buffer)
strncpy(buffer, mntpoint, 256);
return 0;
}
fclose(mounts);
return -ENOENT;
}
/*
* remount_resctrlfs - Remount resctrl FS at /sys/fs/resctrl
* @mum_resctrlfs: Should the resctrl FS be remounted?
*
* If not mounted, mount it.
* If mounted and mum_resctrlfs then remount resctrl FS.
* If mounted and !mum_resctrlfs then noop
*
* Return: 0 on success, non-zero on failure
*/
int remount_resctrlfs(bool mum_resctrlfs)
{
char mountpoint[256];
int ret;
ret = find_resctrl_mount(mountpoint);
if (ret)
strcpy(mountpoint, RESCTRL_PATH);
if (!ret && mum_resctrlfs && umount(mountpoint)) {
printf("not ok unmounting \"%s\"\n", mountpoint);
perror("# umount");
tests_run++;
}
if (!ret && !mum_resctrlfs)
return 0;
ret = mount("resctrl", RESCTRL_PATH, "resctrl", 0, NULL);
printf("%sok mounting resctrl to \"%s\"\n", ret ? "not " : "",
RESCTRL_PATH);
if (ret)
perror("# mount");
tests_run++;
return ret;
}
int umount_resctrlfs(void)
{
if (umount(RESCTRL_PATH)) {
perror("# Unable to umount resctrl");
return errno;
}
return 0;
}
/*
* get_resource_id - Get socket number/l3 id for a specified CPU
* @cpu_no: CPU number
* @resource_id: Socket number or l3_id
*
* Return: >= 0 on success, < 0 on failure.
*/
int get_resource_id(int cpu_no, int *resource_id)
{
char phys_pkg_path[1024];
FILE *fp;
sprintf(phys_pkg_path, "%s%d/topology/physical_package_id",
PHYS_ID_PATH, cpu_no);
fp = fopen(phys_pkg_path, "r");
if (!fp) {
perror("Failed to open physical_package_id");
return -1;
}
if (fscanf(fp, "%d", resource_id) <= 0) {
perror("Could not get socket number or l3 id");
fclose(fp);
return -1;
}
fclose(fp);
return 0;
}
/*
* taskset_benchmark - Taskset PID (i.e. benchmark) to a specified cpu
* @bm_pid: PID that should be binded
* @cpu_no: CPU number at which the PID would be binded
*
* Return: 0 on success, non-zero on failure
*/
int taskset_benchmark(pid_t bm_pid, int cpu_no)
{
cpu_set_t my_set;
CPU_ZERO(&my_set);
CPU_SET(cpu_no, &my_set);
if (sched_setaffinity(bm_pid, sizeof(cpu_set_t), &my_set)) {
perror("Unable to taskset benchmark");
return -1;
}
return 0;
}
/*
* 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
*
* Return: void
*/
void run_benchmark(int signum, siginfo_t *info, void *ucontext)
{
unsigned long span;
int operation, ret;
char **benchmark_cmd;
FILE *fp;
benchmark_cmd = info->si_ptr;
/*
* Direct stdio of child to /dev/null, so that only parent writes to
* stdio (console)
*/
fp = freopen("/dev/null", "w", stdout);
if (!fp)
PARENT_EXIT("Unable to direct benchmark status to /dev/null");
if (strcmp(benchmark_cmd[0], "fill_buf") == 0) {
/* Execute default fill_buf benchmark */
span = strtoul(benchmark_cmd[1], NULL, 10);
operation = atoi(benchmark_cmd[4]);
if (run_fill_buf(span, 1, 1, operation, NULL))
fprintf(stderr, "Error in running fill buffer\n");
} else {
/* Execute specified benchmark */
ret = execvp(benchmark_cmd[0], benchmark_cmd);
if (ret)
perror("wrong\n");
}
fclose(stdout);
PARENT_EXIT("Unable to run specified benchmark");
}
/*
* create_grp - Create a group only if one doesn't exist
* @grp_name: Name of the group
* @grp: Full path and name of the group
* @parent_grp: Full path and name of the parent group
*
* Return: 0 on success, non-zero on failure
*/
static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
{
int found_grp = 0;
struct dirent *ep;
DIR *dp;
/* Check if requested grp exists or not */
dp = opendir(parent_grp);
if (dp) {
while ((ep = readdir(dp)) != NULL) {
if (strcmp(ep->d_name, grp_name) == 0)
found_grp = 1;
}
closedir(dp);
} else {
perror("Unable to open resctrl for group");
return -1;
}
/* Requested grp doesn't exist, hence create it */
if (found_grp == 0) {
if (mkdir(grp, 0) == -1) {
perror("Unable to create group");
return -1;
}
}
return 0;
}
static int write_pid_to_tasks(char *tasks, pid_t pid)
{
FILE *fp;
fp = fopen(tasks, "w");
if (!fp) {
perror("Failed to open tasks file");
return -1;
}
if (fprintf(fp, "%d\n", pid) < 0) {
perror("Failed to wr pid to tasks file");
fclose(fp);
return -1;
}
fclose(fp);
return 0;
}
/*
* write_bm_pid_to_resctrl - Write a PID (i.e. benchmark) to resctrl FS
* @bm_pid: PID that should be written
* @ctrlgrp: Name of the control monitor group (con_mon grp)
* @mongrp: Name of the monitor group (mon grp)
* @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc)
*
* If a con_mon grp is requested, create it and write pid to it, otherwise
* write pid to root con_mon grp.
* If a mon grp is requested, create it and write pid to it, otherwise
* pid is not written, this means that pid is in con_mon grp and hence
* should consult con_mon grp's mon_data directory for results.
*
* Return: 0 on success, non-zero on failure
*/
int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
char *resctrl_val)
{
char controlgroup[128], monitorgroup[512], monitorgroup_p[256];
char tasks[1024];
int ret = 0;
if (strlen(ctrlgrp))
sprintf(controlgroup, "%s/%s", RESCTRL_PATH, ctrlgrp);
else
sprintf(controlgroup, "%s", RESCTRL_PATH);
/* Create control and monitoring group and write pid into it */
ret = create_grp(ctrlgrp, controlgroup, RESCTRL_PATH);
if (ret)
goto out;
sprintf(tasks, "%s/tasks", controlgroup);
ret = write_pid_to_tasks(tasks, bm_pid);
if (ret)
goto out;
/* Create mon grp and write pid into it for "mbm" test */
if ((strcmp(resctrl_val, "mbm") == 0)) {
if (mongrp) {
sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
sprintf(monitorgroup, "%s/%s", monitorgroup_p, mongrp);
ret = create_grp(mongrp, monitorgroup, monitorgroup_p);
if (ret)
goto out;
sprintf(tasks, "%s/mon_groups/%s/tasks",
controlgroup, mongrp);
ret = write_pid_to_tasks(tasks, bm_pid);
if (ret)
goto out;
}
}
out:
printf("%sok writing benchmark parameters to resctrl FS\n",
ret ? "not " : "");
if (ret)
perror("# writing to resctrlfs");
tests_run++;
return ret;
}
/*
* write_schemata - Update schemata of a con_mon grp
* @ctrlgrp: Name of the con_mon grp
* @schemata: Schemata that should be updated to
* @cpu_no: CPU number that the benchmark PID is binded to
* @resctrl_val: Resctrl feature (Eg: mbm, mba.. etc)
*
* Update schemata of a con_mon grp *only* if requested resctrl feature is
* allocation type
*
* Return: 0 on success, non-zero on failure
*/
int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
{
char controlgroup[1024], schema[1024], reason[64];
int resource_id, ret = 0;
FILE *fp;
if (strcmp(resctrl_val, "mba") != 0)
return -ENOENT;
if (!schemata) {
printf("# Skipping empty schemata update\n");
return -1;
}
if (get_resource_id(cpu_no, &resource_id) < 0) {
sprintf(reason, "Failed to get resource id");
ret = -1;
goto out;
}
if (strlen(ctrlgrp) != 0)
sprintf(controlgroup, "%s/%s/schemata", RESCTRL_PATH, ctrlgrp);
else
sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
sprintf(schema, "%s%d%c%s", "MB:", resource_id, '=', schemata);
fp = fopen(controlgroup, "w");
if (!fp) {
sprintf(reason, "Failed to open control group");
ret = -1;
goto out;
}
if (fprintf(fp, "%s\n", schema) < 0) {
sprintf(reason, "Failed to write schemata in control group");
fclose(fp);
ret = -1;
goto out;
}
fclose(fp);
out:
printf("%sok Write schema \"%s\" to resctrl FS%s%s\n",
ret ? "not " : "", schema, ret ? " # " : "",
ret ? reason : "");
tests_run++;
return ret;
}
char *fgrep(FILE *inf, const char *str)
{
char line[256];
int slen = strlen(str);
while (!feof(inf)) {
if (!fgets(line, 256, inf))
break;
if (strncmp(line, str, slen))
continue;
return strdup(line);
}
return NULL;
}
/*
* validate_resctrl_feature_request - Check if requested feature is valid.
* @resctrl_val: Requested feature
*
* Return: 0 on success, non-zero on failure
*/
bool validate_resctrl_feature_request(char *resctrl_val)
{
FILE *inf = fopen("/proc/cpuinfo", "r");
bool found = false;
char *res;
if (!inf)
return false;
res = fgrep(inf, "flags");
if (res) {
char *s = strchr(res, ':');
found = s && !strstr(s, resctrl_val);
free(res);
}
fclose(inf);
return found;
}
int validate_bw_report_request(char *bw_report)
{
if (strcmp(bw_report, "reads") == 0)
return 0;
if (strcmp(bw_report, "writes") == 0)
return 0;
if (strcmp(bw_report, "nt-writes") == 0) {
strcpy(bw_report, "writes");
return 0;
}
if (strcmp(bw_report, "total") == 0)
return 0;
fprintf(stderr, "Requested iMC B/W report type unavailable\n");
return -1;
}
int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
int group_fd, unsigned long flags)
{
int ret;
ret = syscall(__NR_perf_event_open, hw_event, pid, cpu,
group_fd, flags);
return ret;
}