/* vi: set sw=4 ts=4: */
/*
 * A mini 'powertop' utility:
 *   Analyze power consumption on Intel-based laptops.
 * Based on powertop 1.11.
 *
 * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

//applet:IF_POWERTOP(APPLET(powertop, _BB_DIR_BIN, _BB_SUID_DROP))

//kbuild:lib-$(CONFIG_POWERTOP) += powertop.o

//config:config POWERTOP
//config:       bool "powertop"
//config:       default y
//config:       help
//config:         Analyze power consumption on Intel-based laptops

// XXX This should be configurable
#define ENABLE_FEATURE_POWERTOP_PROCIRQ 1

#include "libbb.h"


//#define debug(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
#define debug(fmt, ...) ((void)0)


#define BLOATY_HPET_IRQ_NUM_DETECTION 0
#define MAX_CSTATE_COUNT   8
#define IRQCOUNT           40


#define DEFAULT_SLEEP      10
#define DEFAULT_SLEEP_STR "10"

/* Frequency of the ACPI timer */
#define FREQ_ACPI          3579.545
#define FREQ_ACPI_1000     3579545

/* Max filename length of entry in /sys/devices subsystem */
#define BIG_SYSNAME_LEN    16

typedef unsigned long long ullong;

struct line {
        char *string;
        int count;
        /*int disk_count;*/
};

#if ENABLE_FEATURE_POWERTOP_PROCIRQ
struct irqdata {
        smallint active;
        int number;
        ullong count;
        char irq_desc[32];
};
#endif

struct globals {
        struct line *lines; /* the most often used member */
        int lines_cnt;
        int lines_cumulative_count;
        int maxcstate;
        unsigned total_cpus;
        smallint cant_enable_timer_stats;
#if ENABLE_FEATURE_POWERTOP_PROCIRQ
# if BLOATY_HPET_IRQ_NUM_DETECTION
        smallint scanned_timer_list;
        int percpu_hpet_start;
        int percpu_hpet_end;
# endif
        int interrupt_0;
        int total_interrupt;
        struct irqdata interrupts[IRQCOUNT];
#endif
        ullong start_usage[MAX_CSTATE_COUNT];
        ullong last_usage[MAX_CSTATE_COUNT];
        ullong start_duration[MAX_CSTATE_COUNT];
        ullong last_duration[MAX_CSTATE_COUNT];
#if ENABLE_FEATURE_USE_TERMIOS
        struct termios init_settings;
#endif
};
#define G (*ptr_to_globals)
#define INIT_G() do { \
        SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)

#if ENABLE_FEATURE_USE_TERMIOS
static void reset_term(void)
{
        tcsetattr_stdin_TCSANOW(&G.init_settings);
}

static void sig_handler(int signo UNUSED_PARAM)
{
        reset_term();
        _exit(EXIT_FAILURE);
}
#endif

static int write_str_to_file(const char *fname, const char *str)
{
        FILE *fp = fopen_for_write(fname);
        if (!fp)
                return 1;
        fputs(str, fp);
        fclose(fp);
        return 0;
}

/* Make it more readable */
#define start_timer() write_str_to_file("/proc/timer_stats", "1\n")
#define stop_timer()  write_str_to_file("/proc/timer_stats", "0\n")

static NOINLINE void clear_lines(void)
{
        int i;
        if (G.lines) {
                for (i = 0; i < G.lines_cnt; i++)
                        free(G.lines[i].string);
                free(G.lines);
                G.lines_cnt = 0;
                G.lines = NULL;
        }
}

static void update_lines_cumulative_count(void)
{
        int i;
        for (i = 0; i < G.lines_cnt; i++)
                G.lines_cumulative_count += G.lines[i].count;
}

static int line_compare(const void *p1, const void *p2)
{
        const struct line *a = p1;
        const struct line *b = p2;
        return (b->count /*+ 50 * b->disk_count*/) - (a->count /*+ 50 * a->disk_count*/);
}

static void sort_lines(void)
{
        qsort(G.lines, G.lines_cnt, sizeof(G.lines[0]), line_compare);
}

/* Save C-state usage and duration. Also update maxcstate. */
static void read_cstate_counts(ullong *usage, ullong *duration)
{
        DIR *dir;
        struct dirent *d;

        dir = opendir("/proc/acpi/processor");
        if (!dir)
                return;

        while ((d = readdir(dir)) != NULL) {
                FILE *fp;
                char buf[192];
                int level;
                int len;

                len = strlen(d->d_name); /* "CPUnn" */
                if (len < 3 || len > BIG_SYSNAME_LEN)
                        continue;

                sprintf(buf, "%s/%s/power", "/proc/acpi/processor", d->d_name);
                fp = fopen_for_read(buf);
                if (!fp)
                        continue;

// Example file contents:
// active state:            C0
// max_cstate:              C8
// maximum allowed latency: 2000000000 usec
// states:
//     C1:                  type[C1] promotion[--] demotion[--] latency[001] usage[00006173] duration[00000000000000000000]
//     C2:                  type[C2] promotion[--] demotion[--] latency[001] usage[00085191] duration[00000000000083024907]
//     C3:                  type[C3] promotion[--] demotion[--] latency[017] usage[01017622] duration[00000000017921327182]
                level = 0;
                while (fgets(buf, sizeof(buf), fp)) {
                        char *p = strstr(buf, "age[");
                        if (!p)
                                continue;
                        p += 4;
                        usage[level] += bb_strtoull(p, NULL, 10) + 1;
                        p = strstr(buf, "ation[");
                        if (!p)
                                continue;
                        p += 6;
                        duration[level] += bb_strtoull(p, NULL, 10);

                        if (level >= MAX_CSTATE_COUNT-1)
                                break;
                        level++;
                        if (level > G.maxcstate)  /* update maxcstate */
                                G.maxcstate = level;
                }
                fclose(fp);
        }
        closedir(dir);
}

/* Add line and/or update count */
static void save_line(const char *string, int count)
{
        int i;
        for (i = 0; i < G.lines_cnt; i++) {
                if (strcmp(string, G.lines[i].string) == 0) {
                        /* It's already there, only update count */
                        G.lines[i].count += count;
                        return;
                }
        }

        /* Add new line */
        G.lines = xrealloc_vector(G.lines, 4, G.lines_cnt);
        G.lines[G.lines_cnt].string = xstrdup(string);
        G.lines[G.lines_cnt].count = count;
        /*G.lines[G.lines_cnt].disk_count = 0;*/
        G.lines_cnt++;
}

#if ENABLE_FEATURE_POWERTOP_PROCIRQ
static int is_hpet_irq(const char *name)
{
        char *p;
# if BLOATY_HPET_IRQ_NUM_DETECTION
        long hpet_chan;

        /* Learn the range of existing hpet timers. This is done once */
        if (!G.scanned_timer_list) {
                FILE *fp;
                char buf[80];

                G.scanned_timer_list = true;
                fp = fopen_for_read("/proc/timer_list");
                if (!fp)
                        return 0;

                while (fgets(buf, sizeof(buf), fp)) {
                        p = strstr(buf, "Clock Event Device: hpet");
                        if (!p)
                                continue;
                        p += sizeof("Clock Event Device: hpet")-1;
                        if (!isdigit(*p))
                                continue;
                        hpet_chan = xatoi_positive(p);
                        if (hpet_chan < G.percpu_hpet_start)
                                G.percpu_hpet_start = hpet_chan;
                        if (hpet_chan > G.percpu_hpet_end)
                                G.percpu_hpet_end = hpet_chan;
                }
                fclose(fp);
        }
# endif
//TODO: optimize
        p = strstr(name, "hpet");
        if (!p)
                return 0;
        p += 4;
        if (!isdigit(*p))
                return 0;
# if BLOATY_HPET_IRQ_NUM_DETECTION
        hpet_chan = xatoi_positive(p);
        if (hpet_chan < G.percpu_hpet_start || hpet_chan > G.percpu_hpet_end)
                return 0;
# endif
        return 1;
}

/* Save new IRQ count, return delta from old one */
static int save_irq_count(int irq, ullong count)
{
        int unused = IRQCOUNT;
        int i;
        for (i = 0; i < IRQCOUNT; i++) {
                if (G.interrupts[i].active && G.interrupts[i].number == irq) {
                        ullong old = G.interrupts[i].count;
                        G.interrupts[i].count = count;
                        return count - old;
                }
                if (!G.interrupts[i].active && unused > i)
                        unused = i;
        }
        if (unused < IRQCOUNT) {
                G.interrupts[unused].active = 1;
                G.interrupts[unused].count = count;
                G.interrupts[unused].number = irq;
        }
        return count;
}

/* Read /proc/interrupts, save IRQ counts and IRQ description */
static void process_irq_counts(void)
{
        FILE *fp;
        char buf[128];

        /* Reset values */
        G.interrupt_0 = 0;
        G.total_interrupt = 0;

        fp = xfopen_for_read("/proc/interrupts");
        while (fgets(buf, sizeof(buf), fp)) {
                char irq_desc[sizeof("   <kernel IPI> : ") + sizeof(buf)];
                char *p;
                const char *name;
                int nr;
                ullong count;
                ullong delta;

                p = strchr(buf, ':');
                if (!p)
                        continue;
                /*  0:  143646045  153901007   IO-APIC-edge      timer
                 *   ^
                 */
                *p = '\0';
                /* Deal with non-maskable interrupts -- make up fake numbers */
                nr = index_in_strings("NMI\0RES\0CAL\0TLB\0TRM\0THR\0SPU\0", buf);
                if (nr >= 0) {
                        nr += 20000;
                } else {
                        /* bb_strtou doesn't eat leading spaces, using strtoul */
                        errno = 0;
                        nr = strtoul(buf, NULL, 10);
                        if (errno)
                                continue;
                }
                p++;
                /*  0:  143646045  153901007   IO-APIC-edge      timer
                 *    ^
                 */
                /* Sum counts for this IRQ */
                count = 0;
                while (1) {
                        char *tmp;
                        p = skip_whitespace(p);
                        if (!isdigit(*p))
                                break;
                        count += bb_strtoull(p, &tmp, 10);
                        p = tmp;
                }
                /*   0:  143646045  153901007   IO-APIC-edge      timer
                 * NMI:          1          2   Non-maskable interrupts
                 *                              ^
                 */
                if (nr < 20000) {
                        /* Skip to the interrupt name, e.g. 'timer' */
                        p = strchr(p, ' ');
                        if (!p)
                                continue;
                        p = skip_whitespace(p);
                }

                name = p;
                strchrnul(name, '\n')[0] = '\0';
                /* Save description of the interrupt */
                if (nr >= 20000)
                        sprintf(irq_desc, "   <kernel IPI> : %s", name);
                else
                        sprintf(irq_desc, "    <interrupt> : %s", name);

                delta = save_irq_count(nr, count);

                /* Skip per CPU timer interrupts */
                if (is_hpet_irq(name))
                        continue;

                if (nr != 0 && delta != 0)
                        save_line(irq_desc, delta);

                if (nr == 0)
                        G.interrupt_0 = delta;
                else
                        G.total_interrupt += delta;
        }

        fclose(fp);
}
#else /* !ENABLE_FEATURE_POWERTOP_PROCIRQ */
# define process_irq_counts()  ((void)0)
#endif

static NOINLINE int process_timer_stats(void)
{
        char buf[128];
        char line[15 + 3 + 128];
        int n;
        ullong totalticks;
        FILE *fp;

        buf[0] = '\0';
        totalticks = 0;

        n = 0;
        fp = NULL;
        if (!G.cant_enable_timer_stats)
                fp = fopen_for_read("/proc/timer_stats");
        if (fp) {
// Example file contents:
// Timer Stats Version: v0.2
// Sample period: 1.329 s
//    76,     0 swapper          hrtimer_start_range_ns (tick_sched_timer)
//    88,     0 swapper          hrtimer_start_range_ns (tick_sched_timer)
//    24,  3787 firefox          hrtimer_start_range_ns (hrtimer_wakeup)
//   46D,  1136 kondemand/1      do_dbs_timer (delayed_work_timer_fn)
// ...
//     1,  1656 Xorg             hrtimer_start_range_ns (hrtimer_wakeup)
//     1,  2159 udisks-daemon    hrtimer_start_range_ns (hrtimer_wakeup)
// 331 total events, 249.059 events/sec
                while (fgets(buf, sizeof(buf), fp)) {
                        const char *count, *process, *func;
                        char *p;
                        int idx;
                        unsigned cnt;

                        count = skip_whitespace(buf);
                        p = strchr(count, ',');
                        if (!p)
                                continue;
                        *p++ = '\0';
                        cnt = bb_strtou(count, NULL, 10);
                        if (strcmp(skip_non_whitespace(count), " total events") == 0) {
#if ENABLE_FEATURE_POWERTOP_PROCIRQ
                                n = cnt / G.total_cpus;
                                if (n > 0 && n < G.interrupt_0) {
                                        sprintf(line, "    <interrupt> : %s", "extra timer interrupt");
                                        save_line(line, G.interrupt_0 - n);
                                }
#endif
                                break;
                        }
                        if (strchr(count, 'D'))
                                continue; /* deferred */
                        p = skip_whitespace(p); /* points to pid now */
                        process = NULL;
 get_func_name:
                        p = strchr(p, ' ');
                        if (!p)
                                continue;
                        *p++ = '\0';
                        p = skip_whitespace(p);
                        if (process == NULL) {
                                process = p;
                                goto get_func_name;
                        }
                        func = p;

                        //if (strcmp(process, "swapper") == 0
                        // && strcmp(func, "hrtimer_start_range_ns (tick_sched_timer)\n") == 0
                        //) {
                        //      process = "[kernel scheduler]";
                        //      func = "Load balancing tick";
                        //}

                        if (strncmp(func, "tick_nohz_", 10) == 0)
                                continue;
                        if (strncmp(func, "tick_setup_sched_timer", 20) == 0)
                                continue;
                        //if (strcmp(process, "powertop") == 0)
                        //      continue;

                        idx = index_in_strings("insmod\0modprobe\0swapper\0", process);
                        if (idx != -1) {
                                process = idx < 2 ? "[kernel module]" : "<kernel core>";
                        }

                        strchrnul(p, '\n')[0] = '\0';

                        // 46D\01136\0kondemand/1\0do_dbs_timer (delayed_work_timer_fn)
                        // ^          ^            ^
                        // count      process      func

                        //if (strchr(process, '['))
                                sprintf(line, "%15.15s : %s", process, func);
                        //else
                        //      sprintf(line, "%s", process);
                        save_line(line, cnt);
                }
                fclose(fp);
        }

        return n;
}

#ifdef __i386__
/*
 * Get information about CPU using CPUID opcode.
 */
static void cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx,
                                  unsigned int *edx)
{
        /* EAX value specifies what information to return */
        __asm__(
                "       pushl %%ebx\n"     /* Save EBX */
                "       cpuid\n"
                "       movl %%ebx, %1\n"  /* Save content of EBX */
                "       popl %%ebx\n"      /* Restore EBX */
                : "=a"(*eax), /* Output */
                  "=r"(*ebx),
                  "=c"(*ecx),
                  "=d"(*edx)
                : "0"(*eax),  /* Input */
                  "1"(*ebx),
                  "2"(*ecx),
                  "3"(*edx)
                /* No clobbered registers */
        );
}
#endif

#ifdef __i386__
static NOINLINE void print_intel_cstates(void)
{
        int bios_table[8] = { 0 };
        int nbios = 0;
        DIR *cpudir;
        struct dirent *d;
        int i;
        unsigned eax, ebx, ecx, edx;

        cpudir = opendir("/sys/devices/system/cpu");
        if (!cpudir)
                return;

        /* Loop over cpuN entries */
        while ((d = readdir(cpudir)) != NULL) {
                DIR *dir;
                int len;
                char fname[sizeof("/sys/devices/system/cpu//cpuidle//desc") + 2*BIG_SYSNAME_LEN];

                len = strlen(d->d_name);
                if (len < 3 || len > BIG_SYSNAME_LEN)
                        continue;

                if (!isdigit(d->d_name[3]))
                        continue;

                len = sprintf(fname, "%s/%s/cpuidle", "/sys/devices/system/cpu", d->d_name);
                dir = opendir(fname);
                if (!dir)
                        continue;

                /*
                 * Every C-state has its own stateN directory, that
                 * contains a 'time' and a 'usage' file.
                 */
                while ((d = readdir(dir)) != NULL) {
                        FILE *fp;
                        char buf[64];
                        int n;

                        n = strlen(d->d_name);
                        if (n < 3 || n > BIG_SYSNAME_LEN)
                                continue;

                        sprintf(fname + len, "/%s/desc", d->d_name);
                        fp = fopen_for_read(fname);
                        if (fp) {
                                char *p = fgets(buf, sizeof(buf), fp);
                                fclose(fp);
                                if (!p)
                                        break;
                                p = strstr(p, "MWAIT ");
                                if (p) {
                                        int pos;
                                        p += sizeof("MWAIT ") - 1;
                                        pos = (bb_strtoull(p, NULL, 16) >> 4) + 1;
                                        if (pos >= ARRAY_SIZE(bios_table))
                                                continue;
                                        bios_table[pos]++;
                                        nbios++;
                                }
                        }
                }
                closedir(dir);
        }
        closedir(cpudir);

        if (!nbios)
                return;

        eax = 5;
        ebx = ecx = edx = 0;
        cpuid(&eax, &ebx, &ecx, &edx);
        if (!edx || !(ecx & 1))
                return;

        printf("Your CPU supports the following C-states: ");
        i = 0;
        while (edx) {
                if (edx & 7)
                        printf("C%u ", i);
                edx >>= 4;
                i++;
        }
        bb_putchar('\n');

        /* Print BIOS C-States */
        printf("Your BIOS reports the following C-states: ");
        for (i = 0; i < ARRAY_SIZE(bios_table); i++)
                if (bios_table[i])
                        printf("C%u ", i);

        bb_putchar('\n');
}
#else
# define print_intel_cstates() ((void)0)
#endif

static void show_timerstats(void)
{
        unsigned lines;

        /* Get terminal height */
        get_terminal_width_height(STDOUT_FILENO, NULL, &lines);

        /* We don't have whole terminal just for timerstats */
        lines -= 12;

        if (!G.cant_enable_timer_stats) {
                int i, n = 0;
                char strbuf6[6];

                strbuf6[5] = '\0';
                puts("\nTop causes for wakeups:");
                for (i = 0; i < G.lines_cnt; i++) {
                        if ((G.lines[i].count > 0 /*|| G.lines[i].disk_count > 0*/)
                         && n++ < lines
                        ) {
                                /* NB: upstream powertop prints "(wakeups/sec)",
                                 * we print just "(wakeup counts)".
                                 */
                                /*char c = ' ';
                                if (G.lines[i].disk_count)
                                        c = 'D';*/
                                smart_ulltoa5(G.lines[i].count, strbuf6, " KMGTPEZY");
                                printf(/*" %5.1f%% (%s)%c  %s\n"*/
                                        " %5.1f%% (%s)   %s\n",
                                        G.lines[i].count * 100.0 / G.lines_cumulative_count,
                                        strbuf6, /*c,*/
                                        G.lines[i].string);
                        }
                }
        } else {
                bb_putchar('\n');
                bb_error_msg("no stats available; run as root or"
                                " enable the cpufreq_stats module");
        }
}

// Example display from powertop version 1.11
// Cn                Avg residency       P-states (frequencies)
// C0 (cpu running)        ( 0.5%)         2.00 Ghz     0.0%
// polling           0.0ms ( 0.0%)         1.67 Ghz     0.0%
// C1 mwait          0.0ms ( 0.0%)         1333 Mhz     0.1%
// C2 mwait          0.1ms ( 0.1%)         1000 Mhz    99.9%
// C3 mwait         12.1ms (99.4%)
//
// Wakeups-from-idle per second : 93.6     interval: 15.0s
// no ACPI power usage estimate available
//
// Top causes for wakeups:
//   32.4% ( 26.7)       <interrupt> : extra timer interrupt
//   29.0% ( 23.9)     <kernel core> : hrtimer_start_range_ns (tick_sched_timer)
//    9.0% (  7.5)     <kernel core> : hrtimer_start (tick_sched_timer)
//    6.5% (  5.3)       <interrupt> : ata_piix
//    5.0% (  4.1)             inetd : hrtimer_start_range_ns (hrtimer_wakeup)

//usage:#define powertop_trivial_usage
//usage:       ""
//usage:#define powertop_full_usage "\n\n"
//usage:       "Analyze power consumption on Intel-based laptops\n"

int powertop_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int powertop_main(int UNUSED_PARAM argc, char UNUSED_PARAM **argv)
{
        ullong cur_usage[MAX_CSTATE_COUNT];
        ullong cur_duration[MAX_CSTATE_COUNT];
        char cstate_lines[MAX_CSTATE_COUNT + 2][64];
#if ENABLE_FEATURE_USE_TERMIOS
        struct termios new_settings;
        struct pollfd pfd[1];

        pfd[0].fd = 0;
        pfd[0].events = POLLIN;
#endif

        INIT_G();

#if ENABLE_FEATURE_POWERTOP_PROCIRQ && BLOATY_HPET_IRQ_NUM_DETECTION
        G.percpu_hpet_start = INT_MAX;
        G.percpu_hpet_end = INT_MIN;
#endif

        /* Print warning when we don't have superuser privileges */
        if (geteuid() != 0)
                bb_error_msg("run as root to collect enough information");

        /* Get number of CPUs */
        G.total_cpus = get_cpu_count();

        printf("Collecting data for "DEFAULT_SLEEP_STR" seconds\n");

#if ENABLE_FEATURE_USE_TERMIOS
        tcgetattr(0, (void *)&G.init_settings);
        memcpy(&new_settings, &G.init_settings, sizeof(new_settings));
        /* Turn on unbuffered input, turn off echoing */
        new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
        /* So we don't forget to reset term settings */
        atexit(reset_term);
        bb_signals(BB_FATAL_SIGS, sig_handler);
        tcsetattr_stdin_TCSANOW(&new_settings);
#endif

        /* Collect initial data */
        process_irq_counts();

        /* Read initial usage and duration */
        read_cstate_counts(G.start_usage, G.start_duration);

        /* Copy them to "last" */
        memcpy(G.last_usage, G.start_usage, sizeof(G.last_usage));
        memcpy(G.last_duration, G.start_duration, sizeof(G.last_duration));

        /* Display C-states */
        print_intel_cstates();

        G.cant_enable_timer_stats |= stop_timer(); /* 1 on error */

        /* The main loop */
        for (;;) {
                //double maxsleep = 0.0;
                ullong totalticks, totalevents;
                int i;

                G.cant_enable_timer_stats |= start_timer(); /* 1 on error */
#if !ENABLE_FEATURE_USE_TERMIOS
                sleep(DEFAULT_SLEEP);
#else
                if (safe_poll(pfd, 1, DEFAULT_SLEEP * 1000) > 0) {
                        unsigned char c;
                        if (safe_read(STDIN_FILENO, &c, 1) != 1)
                                break; /* EOF/error */
                        if (c == G.init_settings.c_cc[VINTR])
                                break; /* ^C */
                        if ((c | 0x20) == 'q')
                                break;
                }
#endif
                G.cant_enable_timer_stats |= stop_timer(); /* 1 on error */

                clear_lines();
                process_irq_counts();

                /* Clear the stats */
                memset(cur_duration, 0, sizeof(cur_duration));
                memset(cur_usage, 0, sizeof(cur_usage));

                /* Read them */
                read_cstate_counts(cur_usage, cur_duration);

                /* Count totalticks and totalevents */
                totalticks = totalevents = 0;
                for (i = 0; i < MAX_CSTATE_COUNT; i++) {
                        if (cur_usage[i] != 0) {
                                totalticks += cur_duration[i] - G.last_duration[i];
                                totalevents += cur_usage[i] - G.last_usage[i];
                        }
                }

                /* Clear the screen */
                printf("\033[H\033[J");

                /* Clear C-state lines */
                memset(&cstate_lines, 0, sizeof(cstate_lines));

                if (totalevents == 0 && G.maxcstate <= 1) {
                        /* This should not happen */
                        strcpy(cstate_lines[0], "C-state information is not available\n");
                } else {
                        double percentage;
                        unsigned newticks;

                        newticks = G.total_cpus * DEFAULT_SLEEP * FREQ_ACPI_1000 - totalticks;
                        /* Handle rounding errors: do not display negative values */
                        if ((int)newticks < 0)
                                newticks = 0;

                        sprintf(cstate_lines[0], "Cn\t\t  Avg residency\n");
                        percentage = newticks * 100.0 / (G.total_cpus * DEFAULT_SLEEP * FREQ_ACPI_1000);
                        sprintf(cstate_lines[1], "C0 (cpu running)        (%4.1f%%)\n", percentage);

                        /* Compute values for individual C-states */
                        for (i = 0; i < MAX_CSTATE_COUNT; i++) {
                                if (cur_usage[i] != 0) {
                                        double slept;
                                        slept = (cur_duration[i] - G.last_duration[i])
                                                / (cur_usage[i] - G.last_usage[i] + 0.1) / FREQ_ACPI;
                                        percentage = (cur_duration[i] - G.last_duration[i]) * 100
                                                / (G.total_cpus * DEFAULT_SLEEP * FREQ_ACPI_1000);
                                        sprintf(cstate_lines[i + 2], "C%u\t\t%5.1fms (%4.1f%%)\n",
                                                i + 1, slept, percentage);
                                        //if (maxsleep < slept)
                                        //      maxsleep = slept;
                                }
                        }
                }

                for (i = 0; i < MAX_CSTATE_COUNT + 2; i++)
                        if (cstate_lines[i][0])
                                fputs(cstate_lines[i], stdout);

                i = process_timer_stats();
#if ENABLE_FEATURE_POWERTOP_PROCIRQ
                if (totalevents == 0) {
                        /* No C-state info available, use timerstats */
                        totalevents = i * G.total_cpus + G.total_interrupt;
                        if (i < 0)
                                totalevents += G.interrupt_0 - i;
                }
#endif
                /* Upstream powertop prints wakeups per sec per CPU,
                 * we print just raw wakeup counts.
                 */
//TODO: show real seconds (think about manual refresh)
                printf("\nWakeups-from-idle in %u seconds: %llu\n",
                        DEFAULT_SLEEP,
                        totalevents
                );

                update_lines_cumulative_count();
                sort_lines();
                show_timerstats();
                fflush(stdout);

                /* Clear the stats */
                memset(cur_duration, 0, sizeof(cur_duration));
                memset(cur_usage, 0, sizeof(cur_usage));

                /* Get new values */
                read_cstate_counts(cur_usage, cur_duration);

                /* Save them */
                memcpy(G.last_usage, cur_usage, sizeof(G.last_usage));
                memcpy(G.last_duration, cur_duration, sizeof(G.last_duration));
        } /* for (;;) */

        bb_putchar('\n');

        return EXIT_SUCCESS;
}