Commit 5088741e authored by Patryk Wlazlyn's avatar Patryk Wlazlyn Committed by Len Brown
Browse files

tools/power turbostat: detect and disable unavailable BICs at runtime 



To allow unprivileged user to run turbostat seamlessly.

Signed-off-by: default avatarPatryk Wlazlyn <patryk.wlazlyn@linux.intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent e48934c9

tools/power/x86/turbostat/turbostat.c

+125 −63
Original line number Diff line number Diff line
@@ -1317,13 +1317,6 @@ static void bic_disable_msr_access(void) 
	bic_enabled &= ~bic_msrs;

}



static void bic_disable_perf_access(void)

{

	const unsigned long bic_perf = BIC_IPC;



	bic_enabled &= ~bic_perf;

}



static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu, int group_fd, unsigned long flags)

{

	assert(!no_perf);
@@ -1331,12 +1324,14 @@ static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu 
	return syscall(__NR_perf_event_open, hw_event, pid, cpu, group_fd, flags);

}



static long open_perf_counter_or_fail(int cpu, unsigned int type, unsigned int config, int group_fd, __u64 read_format)

static long open_perf_counter(int cpu, unsigned int type, unsigned int config, int group_fd, __u64 read_format)

{

	struct perf_event_attr attr;

	const pid_t pid = -1;

	const unsigned long flags = 0;



	assert(!no_perf);



	memset(&attr, 0, sizeof(struct perf_event_attr));



	attr.type = type;
@@ -1347,15 +1342,6 @@ static long open_perf_counter_or_fail(int cpu, unsigned int type, unsigned int c 
	attr.read_format = read_format;



	const int fd = perf_event_open(&attr, pid, cpu, group_fd, flags);

	if (fd == -1) {

		if (errno == EACCES) {

			errx(1, "capget(CAP_PERFMON) failed, try \"# setcap cap_sys_admin=ep %s\""

			     " or use --no-perf or run as root", progname);

		} else {

			perror("perf_event_open");

			errx(1, "use --no-perf or run as root");

		}

	}



	return fd;

}
@@ -1365,8 +1351,7 @@ int get_instr_count_fd(int cpu) 
	if (fd_instr_count_percpu[cpu])

		return fd_instr_count_percpu[cpu];



	fd_instr_count_percpu[cpu] =

	    open_perf_counter_or_fail(cpu, PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS, -1, 0);

	fd_instr_count_percpu[cpu] = open_perf_counter(cpu, PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS, -1, 0);



	return fd_instr_count_percpu[cpu];

}
@@ -2833,8 +2818,8 @@ static struct amperf_group_fd open_amperf_fd(int cpu) 
	const unsigned int mperf_config = read_mperf_config();

	struct amperf_group_fd fds = {.aperf = -1,.mperf = -1 };



	fds.aperf = open_perf_counter_or_fail(cpu, msr_type, aperf_config, -1, PERF_FORMAT_GROUP);

	fds.mperf = open_perf_counter_or_fail(cpu, msr_type, mperf_config, fds.aperf, PERF_FORMAT_GROUP);

	fds.aperf = open_perf_counter(cpu, msr_type, aperf_config, -1, PERF_FORMAT_GROUP);

	fds.mperf = open_perf_counter(cpu, msr_type, mperf_config, fds.aperf, PERF_FORMAT_GROUP);



	return fds;

}
@@ -4509,7 +4494,8 @@ void msr_sum_record(void) 


/*

 * set_my_sched_priority(pri)

 * return previous

 * return previous priority on success

 * return value < -20 on failure

 */

int set_my_sched_priority(int priority)

{
@@ -4519,16 +4505,16 @@ int set_my_sched_priority(int priority) 
	errno = 0;

	original_priority = getpriority(PRIO_PROCESS, 0);

	if (errno && (original_priority == -1))

		err(errno, "getpriority");

		return -21;



	retval = setpriority(PRIO_PROCESS, 0, priority);

	if (retval)

		errx(retval, "capget(CAP_SYS_NICE) failed,try \"# setcap cap_sys_nice=ep %s\"", progname);

		return -21;



	errno = 0;

	retval = getpriority(PRIO_PROCESS, 0);

	if (retval != priority)

		err(retval, "getpriority(%d) != setpriority(%d)", retval, priority);

		return -21;



	return original_priority;

}
@@ -4543,6 +4529,9 @@ void turbostat_loop() 


	/*

	 * elevate own priority for interval mode

	 *

	 * ignore on error - we probably don't have permission to set it, but

	 * it's not a big deal

	 */

	set_my_sched_priority(-20);
@@ -4628,10 +4617,13 @@ void check_dev_msr() 
	struct stat sb;

	char pathname[32];



	if (no_msr)

		return;



	sprintf(pathname, "/dev/cpu/%d/msr", base_cpu);

	if (stat(pathname, &sb))

		if (system("/sbin/modprobe msr > /dev/null 2>&1"))

			err(-5, "no /dev/cpu/0/msr, Try \"# modprobe msr\" ");

			no_msr = 1;

}



/*
@@ -4643,47 +4635,51 @@ int check_for_cap_sys_rawio(void) 
{

	cap_t caps;

	cap_flag_value_t cap_flag_value;

	int ret = 0;



	caps = cap_get_proc();

	if (caps == NULL)

		err(-6, "cap_get_proc\n");

		return 1;



	if (cap_get_flag(caps, CAP_SYS_RAWIO, CAP_EFFECTIVE, &cap_flag_value))

		err(-6, "cap_get\n");

	if (cap_get_flag(caps, CAP_SYS_RAWIO, CAP_EFFECTIVE, &cap_flag_value)) {

		ret = 1;

		goto free_and_exit;

	}



	if (cap_flag_value != CAP_SET) {

		warnx("capget(CAP_SYS_RAWIO) failed," " try \"# setcap cap_sys_rawio=ep %s\"", progname);

		return 1;

		ret = 1;

		goto free_and_exit;

	}



free_and_exit:

	if (cap_free(caps) == -1)

		err(-6, "cap_free\n");



	return 0;

	return ret;

}



void check_permissions(void)

void check_msr_permission(void)

{

	int do_exit = 0;

	int failed = 0;

	char pathname[32];



	if (no_msr)

		return;



	/* check for CAP_SYS_RAWIO */

	do_exit += check_for_cap_sys_rawio();

	failed += check_for_cap_sys_rawio();



	/* test file permissions */

	sprintf(pathname, "/dev/cpu/%d/msr", base_cpu);

	if (euidaccess(pathname, R_OK)) {

		do_exit++;

		warn("/dev/cpu/0/msr open failed, try chown or chmod +r /dev/cpu/*/msr, or run with --no-msr");

		failed++;

	}



	/* if all else fails, thell them to be root */

	if (do_exit)

		if (getuid() != 0)

			warnx("... or simply run as root");



	if (do_exit)

		exit(-6);

	if (failed) {

		warnx("Failed to access %s. Some of the counters may not be available\n"

		      "\tRun as root to enable them or use %s to disable the access explicitly", pathname, "--no-msr");

		no_msr = 1;

	}

}



void probe_bclk(void)
@@ -5800,6 +5796,28 @@ void print_dev_latency(void) 
	close(fd);

}



static int has_instr_count_access(void)

{

	int fd;

	int has_access;



	if (no_perf)

		return 0;



	fd = open_perf_counter(base_cpu, PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS, -1, 0);

	has_access = fd != -1;



	if (fd != -1)

		close(fd);



	if (!has_access)

		warnx("Failed to access %s. Some of the counters may not be available\n"

		      "\tRun as root to enable them or use %s to disable the access explicitly",

		      "instructions retired perf counter", "--no-perf");



	return has_access;

}



/*

 * Linux-perf manages the HW instructions-retired counter

 * by enabling when requested, and hiding rollover
@@ -5826,13 +5844,15 @@ void linux_perf_init(void) 


static int has_amperf_access_via_msr(void)

{

	const int cpu = sched_getcpu();

	unsigned long long dummy;



	if (get_msr(cpu, MSR_IA32_APERF, &dummy))

	if (no_msr)

		return 0;



	if (get_msr(base_cpu, MSR_IA32_APERF, &dummy))

		return 0;



	if (get_msr(cpu, MSR_IA32_MPERF, &dummy))

	if (get_msr(base_cpu, MSR_IA32_MPERF, &dummy))

		return 0;



	return 1;
@@ -5840,16 +5860,44 @@ static int has_amperf_access_via_msr(void) 


static int has_amperf_access_via_perf(void)

{

	if (access("/sys/bus/event_source/devices/msr/type", F_OK))

		return 0;

	struct amperf_group_fd fds;



	if (access("/sys/bus/event_source/devices/msr/events/aperf", F_OK))

		return 0;

	/*

	 * Cache the last result, so we don't warn the user multiple times

	 *

	 * Negative means cached, no access

	 * Zero means not cached

	 * Positive means cached, has access

	 */

	static int has_access_cached;



	if (access("/sys/bus/event_source/devices/msr/events/mperf", F_OK))

	if (no_perf)

		return 0;



	return 1;

	if (has_access_cached != 0)

		return has_access_cached > 0;



	fds = open_amperf_fd(base_cpu);

	has_access_cached = (fds.aperf != -1) && (fds.mperf != -1);



	if (fds.aperf == -1)

		warnx("Failed to access %s. Some of the counters may not be available\n"

		      "\tRun as root to enable them or use %s to disable the access explicitly",

		      "APERF perf counter", "--no-perf");

	else

		close(fds.aperf);



	if (fds.mperf == -1)

		warnx("Failed to access %s. Some of the counters may not be available\n"

		      "\tRun as root to enable them or use %s to disable the access explicitly",

		      "MPERF perf counter", "--no-perf");

	else

		close(fds.mperf);



	if (has_access_cached == 0)

		has_access_cached = -1;



	return has_access_cached > 0;

}



/* Check if we can access APERF and MPERF */
@@ -6542,14 +6590,34 @@ static void set_amperf_source(void) 
	fprintf(outf, "aperf/mperf source preference: %s\n", amperf_source == AMPERF_SOURCE_MSR ? "msr" : "perf");

}



void check_msr_access(void)

{

	check_dev_msr();

	check_msr_permission();



	if (no_msr)

		bic_disable_msr_access();

}



void check_perf_access(void)

{

	if (no_perf || !has_instr_count_access())

		bic_enabled &= ~BIC_IPC;



	if (!has_amperf_access()) {

		bic_enabled &= ~BIC_Avg_MHz;

		bic_enabled &= ~BIC_Busy;

		bic_enabled &= ~BIC_Bzy_MHz;

		bic_enabled &= ~BIC_IPC;

	}

}



void turbostat_init()

{

	setup_all_buffers(true);

	set_base_cpu();

	if (!no_msr) {

		check_dev_msr();

		check_permissions();

	}

	check_msr_access();

	check_perf_access();

	process_cpuid();

	probe_pm_features();

	set_amperf_source();
@@ -7150,12 +7218,6 @@ int main(int argc, char **argv) 
	outf = stderr;

	cmdline(argc, argv);



	if (no_msr)

		bic_disable_msr_access();



	if (no_perf)

		bic_disable_perf_access();



	if (!quiet) {

		print_version();

		print_bootcmd();