/*
 * turbostat -- show CPU frequency and C-state residency
 * on modern Intel turbo-capable processors.
 *
 * Copyright (c) 2010, Intel Corporation.
 * Len Brown <len.brown@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/time.h>
#include <stdlib.h>
#include <dirent.h>
#include <string.h>
#include <ctype.h>

#define MSR_TSC 0x10
#define MSR_NEHALEM_PLATFORM_INFO       0xCE
#define MSR_NEHALEM_TURBO_RATIO_LIMIT   0x1AD
#define MSR_APERF       0xE8
#define MSR_MPERF       0xE7
#define MSR_PKG_C2_RESIDENCY    0x60D   /* SNB only */
#define MSR_PKG_C3_RESIDENCY    0x3F8
#define MSR_PKG_C6_RESIDENCY    0x3F9
#define MSR_PKG_C7_RESIDENCY    0x3FA   /* SNB only */
#define MSR_CORE_C3_RESIDENCY   0x3FC
#define MSR_CORE_C6_RESIDENCY   0x3FD
#define MSR_CORE_C7_RESIDENCY   0x3FE   /* SNB only */

char *proc_stat = "/proc/stat";
unsigned int interval_sec = 5;  /* set with -i interval_sec */
unsigned int verbose;           /* set with -v */
unsigned int skip_c0;
unsigned int skip_c1;
unsigned int do_nhm_cstates;
unsigned int do_snb_cstates;
unsigned int has_aperf;
unsigned int units = 1000000000;        /* Ghz etc */
unsigned int genuine_intel;
unsigned int has_invariant_tsc;
unsigned int do_nehalem_platform_info;
unsigned int do_nehalem_turbo_ratio_limit;
unsigned int extra_msr_offset;
double bclk;
unsigned int show_pkg;
unsigned int show_core;
unsigned int show_cpu;

int aperf_mperf_unstable;
int backwards_count;
char *progname;
int need_reinitialize;

int num_cpus;

struct counters {
        unsigned long long tsc;         /* per thread */
        unsigned long long aperf;       /* per thread */
        unsigned long long mperf;       /* per thread */
        unsigned long long c1;  /* per thread (calculated) */
        unsigned long long c3;  /* per core */
        unsigned long long c6;  /* per core */
        unsigned long long c7;  /* per core */
        unsigned long long pc2; /* per package */
        unsigned long long pc3; /* per package */
        unsigned long long pc6; /* per package */
        unsigned long long pc7; /* per package */
        unsigned long long extra_msr;   /* per thread */
        int pkg;
        int core;
        int cpu;
        struct counters *next;
};

struct counters *cnt_even;
struct counters *cnt_odd;
struct counters *cnt_delta;
struct counters *cnt_average;
struct timeval tv_even;
struct timeval tv_odd;
struct timeval tv_delta;

unsigned long long get_msr(int cpu, off_t offset)
{
        ssize_t retval;
        unsigned long long msr;
        char pathname[32];
        int fd;

        sprintf(pathname, "/dev/cpu/%d/msr", cpu);
        fd = open(pathname, O_RDONLY);
        if (fd < 0) {
                perror(pathname);
                need_reinitialize = 1;
                return 0;
        }

        retval = pread(fd, &msr, sizeof msr, offset);
        if (retval != sizeof msr) {
                fprintf(stderr, "cpu%d pread(..., 0x%zx) = %jd\n",
                        cpu, offset, retval);
                exit(-2);
        }

        close(fd);
        return msr;
}

void print_header(void)
{
        if (show_pkg)
                fprintf(stderr, "pk");
        if (show_core)
                fprintf(stderr, " cr");
        if (show_cpu)
                fprintf(stderr, " CPU");
        if (do_nhm_cstates)
                fprintf(stderr, "    %%c0 ");
        if (has_aperf)
                fprintf(stderr, " GHz");
        fprintf(stderr, "  TSC");
        if (do_nhm_cstates)
                fprintf(stderr, "    %%c1");
        if (do_nhm_cstates)
                fprintf(stderr, "    %%c3");
        if (do_nhm_cstates)
                fprintf(stderr, "    %%c6");
        if (do_snb_cstates)
                fprintf(stderr, "    %%c7");
        if (do_snb_cstates)
                fprintf(stderr, "  %%pc2");
        if (do_nhm_cstates)
                fprintf(stderr, "  %%pc3");
        if (do_nhm_cstates)
                fprintf(stderr, "  %%pc6");
        if (do_snb_cstates)
                fprintf(stderr, "  %%pc7");
        if (extra_msr_offset)
                fprintf(stderr, "        MSR 0x%x ", extra_msr_offset);

        putc('\n', stderr);
}

void dump_cnt(struct counters *cnt)
{
        fprintf(stderr, "package: %d ", cnt->pkg);
        fprintf(stderr, "core:: %d ", cnt->core);
        fprintf(stderr, "CPU: %d ", cnt->cpu);
        fprintf(stderr, "TSC: %016llX\n", cnt->tsc);
        fprintf(stderr, "c3: %016llX\n", cnt->c3);
        fprintf(stderr, "c6: %016llX\n", cnt->c6);
        fprintf(stderr, "c7: %016llX\n", cnt->c7);
        fprintf(stderr, "aperf: %016llX\n", cnt->aperf);
        fprintf(stderr, "pc2: %016llX\n", cnt->pc2);
        fprintf(stderr, "pc3: %016llX\n", cnt->pc3);
        fprintf(stderr, "pc6: %016llX\n", cnt->pc6);
        fprintf(stderr, "pc7: %016llX\n", cnt->pc7);
        fprintf(stderr, "msr0x%x: %016llX\n", extra_msr_offset, cnt->extra_msr);
}

void dump_list(struct counters *cnt)
{
        printf("dump_list 0x%p\n", cnt);

        for (; cnt; cnt = cnt->next)
                dump_cnt(cnt);
}

void print_cnt(struct counters *p)
{
        double interval_float;

        interval_float = tv_delta.tv_sec + tv_delta.tv_usec/1000000.0;

        /* topology columns, print blanks on 1st (average) line */
        if (p == cnt_average) {
                if (show_pkg)
                        fprintf(stderr, " ");
                if (show_core)
                        fprintf(stderr, "    ");
                if (show_cpu)
                        fprintf(stderr, "    ");
        } else {
                if (show_pkg)
                        fprintf(stderr, "%d", p->pkg);
                if (show_core)
                        fprintf(stderr, "%4d", p->core);
                if (show_cpu)
                        fprintf(stderr, "%4d", p->cpu);
        }

        /* %c0 */
        if (do_nhm_cstates) {
                if (!skip_c0)
                        fprintf(stderr, "%7.2f", 100.0 * p->mperf/p->tsc);
                else
                        fprintf(stderr, "   ****");
        }

        /* GHz */
        if (has_aperf) {
                if (!aperf_mperf_unstable) {
                        fprintf(stderr, "%5.2f",
                                1.0 * p->tsc / units * p->aperf /
                                p->mperf / interval_float);
                } else {
                        if (p->aperf > p->tsc || p->mperf > p->tsc) {
                                fprintf(stderr, " ****");
                        } else {
                                fprintf(stderr, "%4.1f*",
                                        1.0 * p->tsc /
                                        units * p->aperf /
                                        p->mperf / interval_float);
                        }
                }
        }

        /* TSC */
        fprintf(stderr, "%5.2f", 1.0 * p->tsc/units/interval_float);

        if (do_nhm_cstates) {
                if (!skip_c1)
                        fprintf(stderr, "%7.2f", 100.0 * p->c1/p->tsc);
                else
                        fprintf(stderr, "  ****");
        }
        if (do_nhm_cstates)
                fprintf(stderr, " %6.2f", 100.0 * p->c3/p->tsc);
        if (do_nhm_cstates)
                fprintf(stderr, " %6.2f", 100.0 * p->c6/p->tsc);
        if (do_snb_cstates)
                fprintf(stderr, " %6.2f", 100.0 * p->c7/p->tsc);
        if (do_snb_cstates)
                fprintf(stderr, " %5.2f", 100.0 * p->pc2/p->tsc);
        if (do_nhm_cstates)
                fprintf(stderr, " %5.2f", 100.0 * p->pc3/p->tsc);
        if (do_nhm_cstates)
                fprintf(stderr, " %5.2f", 100.0 * p->pc6/p->tsc);
        if (do_snb_cstates)
                fprintf(stderr, " %5.2f", 100.0 * p->pc7/p->tsc);
        if (extra_msr_offset)
                fprintf(stderr, "  0x%016llx", p->extra_msr);
        putc('\n', stderr);
}

void print_counters(struct counters *counters)
{
        struct counters *cnt;

        print_header();

        if (num_cpus > 1)
                print_cnt(cnt_average);

        for (cnt = counters; cnt != NULL; cnt = cnt->next)
                print_cnt(cnt);

}

#define SUBTRACT_COUNTER(after, before, delta) (delta = (after - before), (before > after))

int compute_delta(struct counters *after,
        struct counters *before, struct counters *delta)
{
        int errors = 0;
        int perf_err = 0;

        skip_c0 = skip_c1 = 0;

        for ( ; after && before && delta;
                after = after->next, before = before->next, delta = delta->next) {
                if (before->cpu != after->cpu) {
                        printf("cpu configuration changed: %d != %d\n",
                                before->cpu, after->cpu);
                        return -1;
                }

                if (SUBTRACT_COUNTER(after->tsc, before->tsc, delta->tsc)) {
                        fprintf(stderr, "cpu%d TSC went backwards %llX to %llX\n",
                                before->cpu, before->tsc, after->tsc);
                        errors++;
                }
                /* check for TSC < 1 Mcycles over interval */
                if (delta->tsc < (1000 * 1000)) {
                        fprintf(stderr, "Insanely slow TSC rate,"
                                " TSC stops in idle?\n");
                        fprintf(stderr, "You can disable all c-states"
                                " by booting with \"idle=poll\"\n");
                        fprintf(stderr, "or just the deep ones with"
                                " \"processor.max_cstate=1\"\n");
                        exit(-3);
                }
                if (SUBTRACT_COUNTER(after->c3, before->c3, delta->c3)) {
                        fprintf(stderr, "cpu%d c3 counter went backwards %llX to %llX\n",
                                before->cpu, before->c3, after->c3);
                        errors++;
                }
                if (SUBTRACT_COUNTER(after->c6, before->c6, delta->c6)) {
                        fprintf(stderr, "cpu%d c6 counter went backwards %llX to %llX\n",
                                before->cpu, before->c6, after->c6);
                        errors++;
                }
                if (SUBTRACT_COUNTER(after->c7, before->c7, delta->c7)) {
                        fprintf(stderr, "cpu%d c7 counter went backwards %llX to %llX\n",
                                before->cpu, before->c7, after->c7);
                        errors++;
                }
                if (SUBTRACT_COUNTER(after->pc2, before->pc2, delta->pc2)) {
                        fprintf(stderr, "cpu%d pc2 counter went backwards %llX to %llX\n",
                                before->cpu, before->pc2, after->pc2);
                        errors++;
                }
                if (SUBTRACT_COUNTER(after->pc3, before->pc3, delta->pc3)) {
                        fprintf(stderr, "cpu%d pc3 counter went backwards %llX to %llX\n",
                                before->cpu, before->pc3, after->pc3);
                        errors++;
                }
                if (SUBTRACT_COUNTER(after->pc6, before->pc6, delta->pc6)) {
                        fprintf(stderr, "cpu%d pc6 counter went backwards %llX to %llX\n",
                                before->cpu, before->pc6, after->pc6);
                        errors++;
                }
                if (SUBTRACT_COUNTER(after->pc7, before->pc7, delta->pc7)) {
                        fprintf(stderr, "cpu%d pc7 counter went backwards %llX to %llX\n",
                                before->cpu, before->pc7, after->pc7);
                        errors++;
                }

                perf_err = SUBTRACT_COUNTER(after->aperf, before->aperf, delta->aperf);
                if (perf_err) {
                        fprintf(stderr, "cpu%d aperf counter went backwards %llX to %llX\n",
                                before->cpu, before->aperf, after->aperf);
                }
                perf_err |= SUBTRACT_COUNTER(after->mperf, before->mperf, delta->mperf);
                if (perf_err) {
                        fprintf(stderr, "cpu%d mperf counter went backwards %llX to %llX\n",
                                before->cpu, before->mperf, after->mperf);
                }
                if (perf_err) {
                        if (!aperf_mperf_unstable) {
                                fprintf(stderr, "%s: APERF or MPERF went backwards *\n", progname);
                                fprintf(stderr, "* Frequency results do not cover entire interval *\n");
                                fprintf(stderr, "* fix this by running Linux-2.6.30 or later *\n");

                                aperf_mperf_unstable = 1;
                        }
                        /*
                         * mperf delta is likely a huge "positive" number
                         * can not use it for calculating c0 time
                         */
                        skip_c0 = 1;
                        skip_c1 = 1;
                }

                /*
                 * As mperf and tsc collection are not atomic,
                 * it is possible for mperf's non-halted cycles
                 * to exceed TSC's all cycles: show c1 = 0% in that case.
                 */
                if (delta->mperf > delta->tsc)
                        delta->c1 = 0;
                else /* normal case, derive c1 */
                        delta->c1 = delta->tsc - delta->mperf
                                - delta->c3 - delta->c6 - delta->c7;

                if (delta->mperf == 0)
                        delta->mperf = 1;       /* divide by 0 protection */

                /*
                 * for "extra msr", just copy the latest w/o subtracting
                 */
                delta->extra_msr = after->extra_msr;
                if (errors) {
                        fprintf(stderr, "ERROR cpu%d before:\n", before->cpu);
                        dump_cnt(before);
                        fprintf(stderr, "ERROR cpu%d after:\n", before->cpu);
                        dump_cnt(after);
                        errors = 0;
                }
        }
        return 0;
}

void compute_average(struct counters *delta, struct counters *avg)
{
        struct counters *sum;

        sum = calloc(1, sizeof(struct counters));
        if (sum == NULL) {
                perror("calloc sum");
                exit(1);
        }

        for (; delta; delta = delta->next) {
                sum->tsc += delta->tsc;
                sum->c1 += delta->c1;
                sum->c3 += delta->c3;
                sum->c6 += delta->c6;
                sum->c7 += delta->c7;
                sum->aperf += delta->aperf;
                sum->mperf += delta->mperf;
                sum->pc2 += delta->pc2;
                sum->pc3 += delta->pc3;
                sum->pc6 += delta->pc6;
                sum->pc7 += delta->pc7;
        }
        avg->tsc = sum->tsc/num_cpus;
        avg->c1 = sum->c1/num_cpus;
        avg->c3 = sum->c3/num_cpus;
        avg->c6 = sum->c6/num_cpus;
        avg->c7 = sum->c7/num_cpus;
        avg->aperf = sum->aperf/num_cpus;
        avg->mperf = sum->mperf/num_cpus;
        avg->pc2 = sum->pc2/num_cpus;
        avg->pc3 = sum->pc3/num_cpus;
        avg->pc6 = sum->pc6/num_cpus;
        avg->pc7 = sum->pc7/num_cpus;

        free(sum);
}

void get_counters(struct counters *cnt)
{
        for ( ; cnt; cnt = cnt->next) {
                cnt->tsc = get_msr(cnt->cpu, MSR_TSC);
                if (do_nhm_cstates)
                        cnt->c3 = get_msr(cnt->cpu, MSR_CORE_C3_RESIDENCY);
                if (do_nhm_cstates)
                        cnt->c6 = get_msr(cnt->cpu, MSR_CORE_C6_RESIDENCY);
                if (do_snb_cstates)
                        cnt->c7 = get_msr(cnt->cpu, MSR_CORE_C7_RESIDENCY);
                if (has_aperf)
                        cnt->aperf = get_msr(cnt->cpu, MSR_APERF);
                if (has_aperf)
                        cnt->mperf = get_msr(cnt->cpu, MSR_MPERF);
                if (do_snb_cstates)
                        cnt->pc2 = get_msr(cnt->cpu, MSR_PKG_C2_RESIDENCY);
                if (do_nhm_cstates)
                        cnt->pc3 = get_msr(cnt->cpu, MSR_PKG_C3_RESIDENCY);
                if (do_nhm_cstates)
                        cnt->pc6 = get_msr(cnt->cpu, MSR_PKG_C6_RESIDENCY);
                if (do_snb_cstates)
                        cnt->pc7 = get_msr(cnt->cpu, MSR_PKG_C7_RESIDENCY);
                if (extra_msr_offset)
                        cnt->extra_msr = get_msr(cnt->cpu, extra_msr_offset);
        }
}

void print_nehalem_info(void)
{
        unsigned long long msr;
        unsigned int ratio;

        if (!do_nehalem_platform_info)
                return;

        msr = get_msr(0, MSR_NEHALEM_PLATFORM_INFO);

        ratio = (msr >> 40) & 0xFF;
        fprintf(stderr, "%d * %.0f = %.0f MHz max efficiency\n",
                ratio, bclk, ratio * bclk);

        ratio = (msr >> 8) & 0xFF;
        fprintf(stderr, "%d * %.0f = %.0f MHz TSC frequency\n",
                ratio, bclk, ratio * bclk);

        if (verbose > 1)
                fprintf(stderr, "MSR_NEHALEM_PLATFORM_INFO: 0x%llx\n", msr);

        if (!do_nehalem_turbo_ratio_limit)
                return;

        msr = get_msr(0, MSR_NEHALEM_TURBO_RATIO_LIMIT);

        ratio = (msr >> 24) & 0xFF;
        if (ratio)
                fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 4 active cores\n",
                        ratio, bclk, ratio * bclk);

        ratio = (msr >> 16) & 0xFF;
        if (ratio)
                fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 3 active cores\n",
                        ratio, bclk, ratio * bclk);

        ratio = (msr >> 8) & 0xFF;
        if (ratio)
                fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 2 active cores\n",
                        ratio, bclk, ratio * bclk);

        ratio = (msr >> 0) & 0xFF;
        if (ratio)
                fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 1 active cores\n",
                        ratio, bclk, ratio * bclk);

}

void free_counter_list(struct counters *list)
{
        struct counters *p;

        for (p = list; p; ) {
                struct counters *free_me;

                free_me = p;
                p = p->next;
                free(free_me);
        }
}

void free_all_counters(void)
{
        free_counter_list(cnt_even);
        cnt_even = NULL;

        free_counter_list(cnt_odd);
        cnt_odd = NULL;

        free_counter_list(cnt_delta);
        cnt_delta = NULL;

        free_counter_list(cnt_average);
        cnt_average = NULL;
}

void insert_counters(struct counters **list,
        struct counters *new)
{
        struct counters *prev;

        /*
         * list was empty
         */
        if (*list == NULL) {
                new->next = *list;
                *list = new;
                return;
        }

        show_cpu = 1;   /* there is more than one CPU */

        /*
         * insert on front of list.
         * It is sorted by ascending package#, core#, cpu#
         */
        if (((*list)->pkg > new->pkg) ||
            (((*list)->pkg == new->pkg) && ((*list)->core > new->core)) ||
            (((*list)->pkg == new->pkg) && ((*list)->core == new->core) && ((*list)->cpu > new->cpu))) {
                new->next = *list;
                *list = new;
                return;
        }

        prev = *list;

        while (prev->next && (prev->next->pkg < new->pkg)) {
                prev = prev->next;
                show_pkg = 1;   /* there is more than 1 package */
        }

        while (prev->next && (prev->next->pkg == new->pkg)
                && (prev->next->core < new->core)) {
                prev = prev->next;
                show_core = 1;  /* there is more than 1 core */
        }

        while (prev->next && (prev->next->pkg == new->pkg)
                && (prev->next->core == new->core)
                && (prev->next->cpu < new->cpu)) {
                prev = prev->next;
        }

        /*
         * insert after "prev"
         */
        new->next = prev->next;
        prev->next = new;
}

void alloc_new_counters(int pkg, int core, int cpu)
{
        struct counters *new;

        if (verbose > 1)
                printf("pkg%d core%d, cpu%d\n", pkg, core, cpu);

        new = (struct counters *)calloc(1, sizeof(struct counters));
        if (new == NULL) {
                perror("calloc");
                exit(1);
        }
        new->pkg = pkg;
        new->core = core;
        new->cpu = cpu;
        insert_counters(&cnt_odd, new);

        new = (struct counters *)calloc(1,
                sizeof(struct counters));
        if (new == NULL) {
                perror("calloc");
                exit(1);
        }
        new->pkg = pkg;
        new->core = core;
        new->cpu = cpu;
        insert_counters(&cnt_even, new);

        new = (struct counters *)calloc(1, sizeof(struct counters));
        if (new == NULL) {
                perror("calloc");
                exit(1);
        }
        new->pkg = pkg;
        new->core = core;
        new->cpu = cpu;
        insert_counters(&cnt_delta, new);

        new = (struct counters *)calloc(1, sizeof(struct counters));
        if (new == NULL) {
                perror("calloc");
                exit(1);
        }
        new->pkg = pkg;
        new->core = core;
        new->cpu = cpu;
        cnt_average = new;
}

int get_physical_package_id(int cpu)
{
        char path[64];
        FILE *filep;
        int pkg;

        sprintf(path, "/sys/devices/system/cpu/cpu%d/topology/physical_package_id", cpu);
        filep = fopen(path, "r");
        if (filep == NULL) {
                perror(path);
                exit(1);
        }
        fscanf(filep, "%d", &pkg);
        fclose(filep);
        return pkg;
}

int get_core_id(int cpu)
{
        char path[64];
        FILE *filep;
        int core;

        sprintf(path, "/sys/devices/system/cpu/cpu%d/topology/core_id", cpu);
        filep = fopen(path, "r");
        if (filep == NULL) {
                perror(path);
                exit(1);
        }
        fscanf(filep, "%d", &core);
        fclose(filep);
        return core;
}

/*
 * run func(index, cpu) on every cpu in /proc/stat
 */

int for_all_cpus(void (func)(int, int, int))
{
        FILE *fp;
        int cpu_count;
        int retval;

        fp = fopen(proc_stat, "r");
        if (fp == NULL) {
                perror(proc_stat);
                exit(1);
        }

        retval = fscanf(fp, "cpu %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d\n");
        if (retval != 0) {
                perror("/proc/stat format");
                exit(1);
        }

        for (cpu_count = 0; ; cpu_count++) {
                int cpu;

                retval = fscanf(fp, "cpu%u %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d\n", &cpu);
                if (retval != 1)
                        break;

                func(get_physical_package_id(cpu), get_core_id(cpu), cpu);
        }
        fclose(fp);
        return cpu_count;
}

void re_initialize(void)
{
        printf("turbostat: topology changed, re-initializing.\n");
        free_all_counters();
        num_cpus = for_all_cpus(alloc_new_counters);
        need_reinitialize = 0;
        printf("num_cpus is now %d\n", num_cpus);
}

void dummy(int pkg, int core, int cpu) { return; }
/*
 * check to see if a cpu came on-line
 */
void verify_num_cpus(void)
{
        int new_num_cpus;

        new_num_cpus = for_all_cpus(dummy);

        if (new_num_cpus != num_cpus) {
                if (verbose)
                        printf("num_cpus was %d, is now  %d\n",
                                num_cpus, new_num_cpus);
                need_reinitialize = 1;
        }
}

void turbostat_loop()
{
restart:
        get_counters(cnt_even);
        gettimeofday(&tv_even, (struct timezone *)NULL);

        while (1) {
                verify_num_cpus();
                if (need_reinitialize) {
                        re_initialize();
                        goto restart;
                }
                sleep(interval_sec);
                get_counters(cnt_odd);
                gettimeofday(&tv_odd, (struct timezone *)NULL);

                compute_delta(cnt_odd, cnt_even, cnt_delta);
                timersub(&tv_odd, &tv_even, &tv_delta);
                compute_average(cnt_delta, cnt_average);
                print_counters(cnt_delta);
                if (need_reinitialize) {
                        re_initialize();
                        goto restart;
                }
                sleep(interval_sec);
                get_counters(cnt_even);
                gettimeofday(&tv_even, (struct timezone *)NULL);
                compute_delta(cnt_even, cnt_odd, cnt_delta);
                timersub(&tv_even, &tv_odd, &tv_delta);
                compute_average(cnt_delta, cnt_average);
                print_counters(cnt_delta);
        }
}

void check_dev_msr()
{
        struct stat sb;

        if (stat("/dev/cpu/0/msr", &sb)) {
                fprintf(stderr, "no /dev/cpu/0/msr\n");
                fprintf(stderr, "Try \"# modprobe msr\"\n");
                exit(-5);
        }
}

void check_super_user()
{
        if (getuid() != 0) {
                fprintf(stderr, "must be root\n");
                exit(-6);
        }
}

int has_nehalem_turbo_ratio_limit(unsigned int family, unsigned int model)
{
        if (!genuine_intel)
                return 0;

        if (family != 6)
                return 0;

        switch (model) {
        case 0x1A:      /* Core i7, Xeon 5500 series - Bloomfield, Gainstown NHM-EP */
        case 0x1E:      /* Core i7 and i5 Processor - Clarksfield, Lynnfield, Jasper Forest */
        case 0x1F:      /* Core i7 and i5 Processor - Nehalem */
        case 0x25:      /* Westmere Client - Clarkdale, Arrandale */
        case 0x2C:      /* Westmere EP - Gulftown */
        case 0x2A:      /* SNB */
        case 0x2D:      /* SNB Xeon */
                return 1;
        case 0x2E:      /* Nehalem-EX Xeon - Beckton */
        case 0x2F:      /* Westmere-EX Xeon - Eagleton */
        default:
                return 0;
        }
}

int is_snb(unsigned int family, unsigned int model)
{
        if (!genuine_intel)
                return 0;

        switch (model) {
        case 0x2A:
        case 0x2D:
                return 1;
        }
        return 0;
}

double discover_bclk(unsigned int family, unsigned int model)
{
        if (is_snb(family, model))
                return 100.00;
        else
                return 133.33;
}

void check_cpuid()
{
        unsigned int eax, ebx, ecx, edx, max_level;
        unsigned int fms, family, model, stepping;

        eax = ebx = ecx = edx = 0;

        asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (0));

        if (ebx == 0x756e6547 && edx == 0x49656e69 && ecx == 0x6c65746e)
                genuine_intel = 1;

        if (verbose)
                fprintf(stderr, "%.4s%.4s%.4s ",
                        (char *)&ebx, (char *)&edx, (char *)&ecx);

        asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx");
        family = (fms >> 8) & 0xf;
        model = (fms >> 4) & 0xf;
        stepping = fms & 0xf;
        if (family == 6 || family == 0xf)
                model += ((fms >> 16) & 0xf) << 4;

        if (verbose)
                fprintf(stderr, "%d CPUID levels; family:model:stepping 0x%x:%x:%x (%d:%d:%d)\n",
                        max_level, family, model, stepping, family, model, stepping);

        if (!(edx & (1 << 5))) {
                fprintf(stderr, "CPUID: no MSR\n");
                exit(1);
        }

        /*
         * check max extended function levels of CPUID.
         * This is needed to check for invariant TSC.
         * This check is valid for both Intel and AMD.
         */
        ebx = ecx = edx = 0;
        asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (0x80000000));

        if (max_level < 0x80000007) {
                fprintf(stderr, "CPUID: no invariant TSC (max_level 0x%x)\n", max_level);
                exit(1);
        }

        /*
         * Non-Stop TSC is advertised by CPUID.EAX=0x80000007: EDX.bit8
         * this check is valid for both Intel and AMD
         */
        asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (0x80000007));
        has_invariant_tsc = edx & (1 << 8);

        if (!has_invariant_tsc) {
                fprintf(stderr, "No invariant TSC\n");
                exit(1);
        }

        /*
         * APERF/MPERF is advertised by CPUID.EAX=0x6: ECX.bit0
         * this check is valid for both Intel and AMD
         */

        asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (0x6));
        has_aperf = ecx & (1 << 0);
        if (!has_aperf) {
                fprintf(stderr, "No APERF MSR\n");
                exit(1);
        }

        do_nehalem_platform_info = genuine_intel && has_invariant_tsc;
        do_nhm_cstates = genuine_intel; /* all Intel w/ non-stop TSC have NHM counters */
        do_snb_cstates = is_snb(family, model);
        bclk = discover_bclk(family, model);

        do_nehalem_turbo_ratio_limit = has_nehalem_turbo_ratio_limit(family, model);
}


void usage()
{
        fprintf(stderr, "%s: [-v] [-M MSR#] [-i interval_sec | command ...]\n",
                progname);
        exit(1);
}


/*
 * in /dev/cpu/ return success for names that are numbers
 * ie. filter out ".", "..", "microcode".
 */
int dir_filter(const struct dirent *dirp)
{
        if (isdigit(dirp->d_name[0]))
                return 1;
        else
                return 0;
}

int open_dev_cpu_msr(int dummy1)
{
        return 0;
}

void turbostat_init()
{
        check_cpuid();

        check_dev_msr();
        check_super_user();

        num_cpus = for_all_cpus(alloc_new_counters);

        if (verbose)
                print_nehalem_info();
}

int fork_it(char **argv)
{
        int retval;
        pid_t child_pid;
        get_counters(cnt_even);
        gettimeofday(&tv_even, (struct timezone *)NULL);

        child_pid = fork();
        if (!child_pid) {
                /* child */
                execvp(argv[0], argv);
        } else {
                int status;

                /* parent */
                if (child_pid == -1) {
                        perror("fork");
                        exit(1);
                }

                signal(SIGINT, SIG_IGN);
                signal(SIGQUIT, SIG_IGN);
                if (waitpid(child_pid, &status, 0) == -1) {
                        perror("wait");
                        exit(1);
                }
        }
        get_counters(cnt_odd);
        gettimeofday(&tv_odd, (struct timezone *)NULL);
        retval = compute_delta(cnt_odd, cnt_even, cnt_delta);

        timersub(&tv_odd, &tv_even, &tv_delta);
        compute_average(cnt_delta, cnt_average);
        if (!retval)
                print_counters(cnt_delta);

        fprintf(stderr, "%.6f sec\n", tv_delta.tv_sec + tv_delta.tv_usec/1000000.0);

        return 0;
}

void cmdline(int argc, char **argv)
{
        int opt;

        progname = argv[0];

        while ((opt = getopt(argc, argv, "+vi:M:")) != -1) {
                switch (opt) {
                case 'v':
                        verbose++;
                        break;
                case 'i':
                        interval_sec = atoi(optarg);
                        break;
                case 'M':
                        sscanf(optarg, "%x", &extra_msr_offset);
                        if (verbose > 1)
                                fprintf(stderr, "MSR 0x%X\n", extra_msr_offset);
                        break;
                default:
                        usage();
                }
        }
}

int main(int argc, char **argv)
{
        cmdline(argc, argv);

        if (verbose > 1)
                fprintf(stderr, "turbostat Dec 6, 2010"
                        " - Len Brown <lenb@kernel.org>\n");
        if (verbose > 1)
                fprintf(stderr, "http://userweb.kernel.org/~lenb/acpi/utils/pmtools/turbostat/\n");

        turbostat_init();

        /*
         * if any params left, it must be a command to fork
         */
        if (argc - optind)
                return fork_it(argv + optind);
        else
                turbostat_loop();

        return 0;
}