From 5088741ec805cd249e27c7176ed09bdab164960e Mon Sep 17 00:00:00 2001 From: Patryk Wlazlyn Date: Mon, 15 Jan 2024 19:04:21 +0100 Subject: tools/power turbostat: detect and disable unavailable BICs at runtime To allow unprivileged user to run turbostat seamlessly. Signed-off-by: Patryk Wlazlyn Signed-off-by: Len Brown --- tools/power/x86/turbostat/turbostat.c | 188 ++++++++++++++++++++++------------ 1 file changed, 125 insertions(+), 63 deletions(-) (limited to 'tools') diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index 1294c46c2170..30db6e92193a 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -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 @@ release_msr: /* * 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 @@ skip_cgroup_setting: 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(); -- cgit v1.2.3-58-ga151