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

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To allow unprivileged user to run turbostat seamlessly.

Signed-off-by: Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Patryk Wlazlyn 2024-01-15 19:04:21 +01:00 committed by Len Brown
parent e48934c9f1
commit 5088741ec8
1 changed files with 127 additions and 65 deletions
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192
tools/power/x86/turbostat/turbostat.c
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@ -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");
if (cap_get_flag(caps, CAP_SYS_RAWIO, CAP_EFFECTIVE, &cap_flag_value))
err(-6, "cap_get\n");
if (cap_flag_value != CAP_SET) {
warnx("capget(CAP_SYS_RAWIO) failed," " try \"# setcap cap_sys_rawio=ep %s\"", progname);
return 1;
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) {
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(cpu, MSR_IA32_MPERF, &dummy))
if (get_msr(base_cpu, MSR_IA32_APERF, &dummy))
return 0;
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))
struct amperf_group_fd fds;
/*
* 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 (no_perf)
return 0;
if (access("/sys/bus/event_source/devices/msr/events/aperf", F_OK))
return 0;
if (has_access_cached != 0)
return has_access_cached > 0;
if (access("/sys/bus/event_source/devices/msr/events/mperf", F_OK))
return 0;
fds = open_amperf_fd(base_cpu);
has_access_cached = (fds.aperf != -1) && (fds.mperf != -1);
return 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();