diff options
Diffstat (limited to 'tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c')
| -rw-r--r-- | tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c | 177 |
1 files changed, 154 insertions, 23 deletions
diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c index 3fe1eed900d4..ebda9c366b2b 100644 --- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c +++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c @@ -91,6 +91,9 @@ unsigned int has_hwp_request_pkg; /* IA32_HWP_REQUEST_PKG */ unsigned int bdx_highest_ratio; +#define PATH_TO_CPU "/sys/devices/system/cpu/" +#define SYSFS_PATH_MAX 255 + /* * maintain compatibility with original implementation, but don't document it: */ @@ -622,6 +625,57 @@ void cmdline(int argc, char **argv) } } +/* + * Open a file, and exit on failure + */ +FILE *fopen_or_die(const char *path, const char *mode) +{ + FILE *filep = fopen(path, "r"); + + if (!filep) + err(1, "%s: open failed", path); + return filep; +} + +void err_on_hypervisor(void) +{ + FILE *cpuinfo; + char *flags, *hypervisor; + char *buffer; + + /* On VMs /proc/cpuinfo contains a "flags" entry for hypervisor */ + cpuinfo = fopen_or_die("/proc/cpuinfo", "ro"); + + buffer = malloc(4096); + if (!buffer) { + fclose(cpuinfo); + err(-ENOMEM, "buffer malloc fail"); + } + + if (!fread(buffer, 1024, 1, cpuinfo)) { + fclose(cpuinfo); + free(buffer); + err(1, "Reading /proc/cpuinfo failed"); + } + + flags = strstr(buffer, "flags"); + rewind(cpuinfo); + fseek(cpuinfo, flags - buffer, SEEK_SET); + if (!fgets(buffer, 4096, cpuinfo)) { + fclose(cpuinfo); + free(buffer); + err(1, "Reading /proc/cpuinfo failed"); + } + fclose(cpuinfo); + + hypervisor = strstr(buffer, "hypervisor"); + + free(buffer); + + if (hypervisor) + err(-1, + "not supported on this virtual machine"); +} int get_msr(int cpu, int offset, unsigned long long *msr) { @@ -635,8 +689,10 @@ int get_msr(int cpu, int offset, unsigned long long *msr) err(-1, "%s open failed, try chown or chmod +r /dev/cpu/*/msr, or run as root", pathname); retval = pread(fd, msr, sizeof(*msr), offset); - if (retval != sizeof(*msr)) + if (retval != sizeof(*msr)) { + err_on_hypervisor(); err(-1, "%s offset 0x%llx read failed", pathname, (unsigned long long)offset); + } if (debug > 1) fprintf(stderr, "get_msr(cpu%d, 0x%X, 0x%llX)\n", cpu, offset, *msr); @@ -668,6 +724,48 @@ int put_msr(int cpu, int offset, unsigned long long new_msr) return 0; } +static unsigned int read_sysfs(const char *path, char *buf, size_t buflen) +{ + ssize_t numread; + int fd; + + fd = open(path, O_RDONLY); + if (fd == -1) + return 0; + + numread = read(fd, buf, buflen - 1); + if (numread < 1) { + close(fd); + return 0; + } + + buf[numread] = '\0'; + close(fd); + + return (unsigned int) numread; +} + +static unsigned int write_sysfs(const char *path, char *buf, size_t buflen) +{ + ssize_t numwritten; + int fd; + + fd = open(path, O_WRONLY); + if (fd == -1) + return 0; + + numwritten = write(fd, buf, buflen - 1); + if (numwritten < 1) { + perror("write failed\n"); + close(fd); + return -1; + } + + close(fd); + + return (unsigned int) numwritten; +} + void print_hwp_cap(int cpu, struct msr_hwp_cap *cap, char *str) { if (cpu != -1) @@ -745,17 +843,61 @@ void write_hwp_request(int cpu, struct msr_hwp_request *hwp_req, unsigned int ms put_msr(cpu, msr_offset, msr); } +static int get_epb(int cpu) +{ + char path[SYSFS_PATH_MAX]; + char linebuf[3]; + char *endp; + long val; + + if (!has_epb) + return -1; + + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/power/energy_perf_bias", cpu); + + if (!read_sysfs(path, linebuf, 3)) + return -1; + + val = strtol(linebuf, &endp, 0); + if (endp == linebuf || errno == ERANGE) + return -1; + + return (int)val; +} + +static int set_epb(int cpu, int val) +{ + char path[SYSFS_PATH_MAX]; + char linebuf[3]; + char *endp; + int ret; + + if (!has_epb) + return -1; + + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/power/energy_perf_bias", cpu); + snprintf(linebuf, sizeof(linebuf), "%d", val); + + ret = write_sysfs(path, linebuf, 3); + if (ret <= 0) + return -1; + + val = strtol(linebuf, &endp, 0); + if (endp == linebuf || errno == ERANGE) + return -1; + + return (int)val; +} + int print_cpu_msrs(int cpu) { - unsigned long long msr; struct msr_hwp_request req; struct msr_hwp_cap cap; + int epb; - if (has_epb) { - get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &msr); - - printf("cpu%d: EPB %u\n", cpu, (unsigned int) msr); - } + epb = get_epb(cpu); + if (epb >= 0) + printf("cpu%d: EPB %u\n", cpu, (unsigned int) epb); if (!has_hwp) return 0; @@ -1038,15 +1180,15 @@ int enable_hwp_on_cpu(int cpu) int update_cpu_msrs(int cpu) { unsigned long long msr; - + int epb; if (update_epb) { - get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &msr); - put_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, new_epb); + epb = get_epb(cpu); + set_epb(cpu, new_epb); if (verbose) printf("cpu%d: ENERGY_PERF_BIAS old: %d new: %d\n", - cpu, (unsigned int) msr, (unsigned int) new_epb); + cpu, epb, (unsigned int) new_epb); } if (update_turbo) { @@ -1086,18 +1228,6 @@ int update_cpu_msrs(int cpu) return 0; } -/* - * Open a file, and exit on failure - */ -FILE *fopen_or_die(const char *path, const char *mode) -{ - FILE *filep = fopen(path, "r"); - - if (!filep) - err(1, "%s: open failed", path); - return filep; -} - unsigned int get_pkg_num(int cpu) { FILE *fp; @@ -1111,6 +1241,7 @@ unsigned int get_pkg_num(int cpu) retval = fscanf(fp, "%d\n", &pkg); if (retval != 1) errx(1, "%s: failed to parse", pathname); + fclose(fp); return pkg; } |