mpstat: new applet. ~5.5k

Signed-off-by: Marek Polacek <mmpolacek@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 1024 insertions, 0 deletions

diff --git a/procps/mpstat.c b/procps/mpstat.c
new file mode 100644
index 0000000..0f633c7
--- /dev/null
+++ b/procps/mpstat.c
@@ -0,0 +1,1024 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Per-processor statistics, based on sysstat version 9.1.2 by Sebastien Godard
+ *
+ * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
+ *
+ * Licensed under GPLv2, see file License in this tarball for details.
+ */
+
+//applet:IF_MPSTAT(APPLET(mpstat, _BB_DIR_BIN, _BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_MPSTAT) += mpstat.o
+
+//config:config MPSTAT
+//config:	bool "mpstat"
+//config:	default y
+//config:	help
+//config:	  Per-processor statistics
+
+#include "libbb.h"
+#include <sys/utsname.h>	/* struct utsname */
+
+//#define debug(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
+#define debug(fmt, ...) ((void)0)
+
+/* Size of /proc/interrupts line, CPU data excluded */
+#define INTERRUPTS_LINE    64
+/* Maximum number of interrupts */
+#define NR_IRQS            256
+#define NR_IRQCPU_PREALLOC 3
+#define MAX_IRQ_LEN        16
+#define MAX_PF_NAME        512
+
+/* System files */
+#define SYSFS_DEVCPU      "/sys/devices/system/cpu"
+#define PROCFS_STAT       "/proc/stat"
+#define PROCFS_INTERRUPTS "/proc/interrupts"
+#define PROCFS_SOFTIRQS   "/proc/softirqs"
+#define PROCFS_UPTIME     "/proc/uptime"
+
+
+#if 1
+typedef unsigned long long data_t;
+typedef long long idata_t;
+#define FMT_DATA "ll"
+#define DATA_MAX ULLONG_MAX
+#else
+typedef unsigned long data_t;
+typedef long idata_t;
+#define FMT_DATA "l"
+#define DATA_MAX ULONG_MAX
+#endif
+
+
+struct stats_irqcpu {
+	unsigned interrupt;
+	char irq_name[MAX_IRQ_LEN];
+};
+
+/* Structure for CPU statistics */
+struct stats_cpu {
+	data_t cpu_user;
+	data_t cpu_nice;
+	data_t cpu_system;
+	data_t cpu_idle;
+	data_t cpu_iowait;
+	data_t cpu_steal;
+	data_t cpu_irq;
+	data_t cpu_softirq;
+	data_t cpu_guest;
+};
+
+/* Struct for interrupts statistics */
+struct stats_irq {
+	data_t irq_nr;
+};
+
+
+/* Globals. Try to sort by size. */
+struct globals {
+	int interval;
+	int count;
+	unsigned cpu_nr;                /* Number of CPUs */
+	unsigned irqcpu_nr;             /* Number of interrupts per CPU */
+	unsigned softirqcpu_nr;         /* Number of soft interrupts per CPU */
+	unsigned options;
+	unsigned hz;
+	unsigned cpu_bitmap_len;
+	smallint p_option;
+	smallint header_done;
+	smallint avg_header_done;
+	unsigned char *cpu_bitmap;      /* Bit 0: global, bit 1: 1st proc... */
+	data_t global_uptime[3];
+	data_t per_cpu_uptime[3];
+	struct stats_cpu *st_cpu[3];
+	struct stats_irq *st_irq[3];
+	struct stats_irqcpu *st_irqcpu[3];
+	struct stats_irqcpu *st_softirqcpu[3];
+	struct tm timestamp[3];
+};
+#define G (*ptr_to_globals)
+#define INIT_G() do { \
+	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+} while (0)
+
+/* The selected interrupts statistics (bits in G.options) */
+enum {
+	D_CPU      = 1 << 0,
+	D_IRQ_SUM  = 1 << 1,
+	D_IRQ_CPU  = 1 << 2,
+	D_SOFTIRQS = 1 << 3,
+};
+
+
+/* Does str start with "cpu"? */
+static int starts_with_cpu(const char *str)
+{
+	return !((str[0] - 'c') | (str[1] - 'p') | (str[2] - 'u'));
+}
+
+/* Is option on? */
+static ALWAYS_INLINE int display_opt(int opt)
+{
+	return (opt & G.options);
+}
+
+#if DATA_MAX > 0xffffffff
+/*
+ * Handle overflow conditions properly for counters which can have
+ * less bits than data_t, depending on the kernel version.
+ */
+/* Surprisingly, on 32bit inlining is a size win */
+static ALWAYS_INLINE data_t overflow_safe_sub(data_t prev, data_t curr)
+{
+	data_t v = curr - prev;
+
+	if ((idata_t)v < 0     /* curr < prev - counter overflow? */
+	 && prev <= 0xffffffff /* kernel uses 32bit value for the counter? */
+	) {
+		/* Add 33th bit set to 1 to curr, compensating for the overflow */
+		/* double shift defeats "warning: left shift count >= width of type" */
+		v += ((data_t)1 << 16) << 16;
+	}
+	return v;
+}
+#else
+static ALWAYS_INLINE data_t overflow_safe_sub(data_t prev, data_t curr)
+{
+	return curr - prev;
+}
+#endif
+
+static double percent_value(data_t prev, data_t curr, data_t itv)
+{
+	return ((double)overflow_safe_sub(prev, curr)) / itv * 100;
+}
+
+static double hz_value(data_t prev, data_t curr, data_t itv)
+{
+	return ((double)overflow_safe_sub(prev, curr)) / itv * G.hz;
+}
+
+static ALWAYS_INLINE data_t jiffies_diff(data_t old, data_t new)
+{
+	data_t diff = new - old;
+	return (diff == 0) ? 1 : diff;
+}
+
+static int is_cpu_in_bitmap(unsigned cpu)
+{
+	return G.cpu_bitmap[cpu >> 3] & (1 << (cpu & 7));
+}
+
+static void write_irqcpu_stats(struct stats_irqcpu *per_cpu_stats[],
+		int total_irqs,
+		data_t itv,
+		int prev, int current,
+		const char *prev_str, const char *current_str)
+{
+	int j;
+	int offset, cpu;
+	struct stats_irqcpu *p0, *q0;
+
+	/* Check if number of IRQs has changed */
+	if (G.interval != 0) {
+		for (j = 0; j <= total_irqs; j++) {
+			p0 = &per_cpu_stats[current][j];
+			if (p0->irq_name[0] != '\0') {
+				q0 = &per_cpu_stats[prev][j];
+				if (strcmp(p0->irq_name, q0->irq_name) != 0) {
+					/* Strings are different */
+					break;
+				}
+			}
+		}
+	}
+
+	/* Print header */
+	printf("\n%-11s  CPU", prev_str);
+	for (j = 0; j < total_irqs; j++) {
+		p0 = &per_cpu_stats[current][j];
+		if (p0->irq_name[0] != '\0')
+			printf(" %8s/s", p0->irq_name);
+	}
+	bb_putchar('\n');
+
+	for (cpu = 1; cpu <= G.cpu_nr; cpu++) {
+		/* Check if we want stats about this CPU */
+		if (!is_cpu_in_bitmap(cpu) && G.p_option) {
+			continue;
+		}
+
+		printf("%-11s %4u", current_str, cpu - 1);
+
+		for (j = 0; j < total_irqs; j++) {
+			/* IRQ field set only for proc 0 */
+			p0 = &per_cpu_stats[current][j];
+
+			/*
+			 * An empty string for irq name means that
+			 * interrupt is no longer used.
+			 */
+			if (p0->irq_name[0] != '\0') {
+				offset = j;
+				q0 = &per_cpu_stats[prev][offset];
+
+				/*
+				 * If we want stats for the time since boot
+				 * we have p0->irq != q0->irq.
+				 */
+				if (strcmp(p0->irq_name, q0->irq_name) != 0
+				 && G.interval != 0
+				) {
+					if (j) {
+						offset = j - 1;
+						q0 = &per_cpu_stats[prev][offset];
+					}
+					if (strcmp(p0->irq_name, q0->irq_name) != 0
+					 && (j + 1 < total_irqs)
+					) {
+						offset = j + 1;
+						q0 = &per_cpu_stats[prev][offset];
+					}
+				}
+
+				if (strcmp(p0->irq_name, q0->irq_name) == 0
+				 || G.interval == 0
+				) {
+					struct stats_irqcpu *p, *q;
+					p = &per_cpu_stats[current][(cpu - 1) * total_irqs + j];
+					q = &per_cpu_stats[prev][(cpu - 1) * total_irqs + offset];
+					printf(" %10.2f",
+						(double)(p->interrupt - q->interrupt) / itv * G.hz);
+				} else {
+					printf("        N/A");
+				}
+			}
+		}
+		bb_putchar('\n');
+	}
+}
+
+static data_t get_per_cpu_interval(const struct stats_cpu *scc,
+		const struct stats_cpu *scp)
+{
+	return ((scc->cpu_user + scc->cpu_nice +
+		 scc->cpu_system + scc->cpu_iowait +
+		 scc->cpu_idle + scc->cpu_steal +
+		 scc->cpu_irq + scc->cpu_softirq) -
+		(scp->cpu_user + scp->cpu_nice +
+		 scp->cpu_system + scp->cpu_iowait +
+		 scp->cpu_idle + scp->cpu_steal +
+		 scp->cpu_irq + scp->cpu_softirq));
+}
+
+static void print_stats_cpu_struct(const struct stats_cpu *p,
+		const struct stats_cpu *c,
+		data_t itv)
+{
+	printf(" %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n",
+		percent_value(p->cpu_user - p->cpu_guest,
+		/**/                          c->cpu_user - c->cpu_guest, itv),
+		percent_value(p->cpu_nice   , c->cpu_nice   , itv),
+		percent_value(p->cpu_system , c->cpu_system , itv),
+		percent_value(p->cpu_iowait , c->cpu_iowait , itv),
+		percent_value(p->cpu_irq    , c->cpu_irq    , itv),
+		percent_value(p->cpu_softirq, c->cpu_softirq, itv),
+		percent_value(p->cpu_steal  , c->cpu_steal  , itv),
+		percent_value(p->cpu_guest  , c->cpu_guest  , itv),
+		percent_value(p->cpu_idle   , c->cpu_idle   , itv)
+	);
+}
+
+static void write_stats_core(int prev, int current,
+		const char *prev_str, const char *current_str)
+{
+	struct stats_cpu *scc, *scp;
+	data_t itv, global_itv;
+	int cpu;
+
+	/* Compute time interval */
+	itv = global_itv = jiffies_diff(G.global_uptime[prev], G.global_uptime[current]);
+
+	/* Reduce interval to one CPU */
+	if (G.cpu_nr > 1)
+		itv = jiffies_diff(G.per_cpu_uptime[prev], G.per_cpu_uptime[current]);
+
+	/* Print CPU stats */
+	if (display_opt(D_CPU)) {
+
+		/* This is done exactly once */
+		if (!G.header_done) {
+			printf("\n%-11s  CPU    %%usr   %%nice    %%sys %%iowait    %%irq   %%soft  %%steal  %%guest   %%idle\n",
+				prev_str
+			);
+			G.header_done = 1;
+		}
+
+		for (cpu = 0; cpu <= G.cpu_nr; cpu++) {
+			data_t per_cpu_itv;
+
+			/* Print stats about this particular CPU? */
+			if (!is_cpu_in_bitmap(cpu))
+				continue;
+
+			scc = &G.st_cpu[current][cpu];
+			scp = &G.st_cpu[prev][cpu];
+			per_cpu_itv = global_itv;
+
+			printf((cpu ? "%-11s %4u" : "%-11s  all"), current_str, cpu - 1);
+			if (cpu) {
+				double idle;
+				/*
+				 * If the CPU is offline, then it isn't in /proc/stat,
+				 * so all values are 0.
+				 * NB: Guest time is already included in user time.
+				 */
+				if ((scc->cpu_user | scc->cpu_nice | scc->cpu_system |
+				     scc->cpu_iowait | scc->cpu_idle | scc->cpu_steal |
+				     scc->cpu_irq | scc->cpu_softirq) == 0
+				) {
+					/*
+					 * Set current struct fields to values from prev.
+					 * iteration. Then their values won't jump from
+					 * zero, when the CPU comes back online.
+					 */
+					*scc = *scp;
+					idle = 0.0;
+					goto print_zeros;
+				}
+				/* Compute interval again for current proc */
+				per_cpu_itv = get_per_cpu_interval(scc, scp);
+				if (per_cpu_itv == 0) {
+					/*
+					 * If the CPU is tickless then there is no change in CPU values
+					 * but the sum of values is not zero.
+					 */
+					idle = 100.0;
+ print_zeros:
+					printf(" %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n",
+						0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, idle);
+					continue;
+				}
+			}
+			print_stats_cpu_struct(scp, scc, per_cpu_itv);
+		}
+	}
+
+	/* Print total number of IRQs per CPU */
+	if (display_opt(D_IRQ_SUM)) {
+
+		/* Print average header, this is done exactly once */
+		if (!G.avg_header_done) {
+			printf("\n%-11s  CPU    intr/s\n", prev_str);
+			G.avg_header_done = 1;
+		}
+
+		for (cpu = 0; cpu <= G.cpu_nr; cpu++) {
+			data_t per_cpu_itv;
+
+			/* Print stats about this CPU? */
+			if (!is_cpu_in_bitmap(cpu))
+				continue;
+
+			per_cpu_itv = itv;
+			printf((cpu ? "%-11s %4u" : "%-11s  all"), current_str, cpu - 1);
+			if (cpu) {
+				scc = &G.st_cpu[current][cpu];
+				scp = &G.st_cpu[prev][cpu];
+				/* Compute interval again for current proc */
+				per_cpu_itv = get_per_cpu_interval(scc, scp);
+				if (per_cpu_itv == 0) {
+					printf(" %9.2f\n", 0.0);
+					continue;
+				}
+			}
+			printf(" %9.2f\n", hz_value(G.st_irq[prev][cpu].irq_nr, G.st_irq[current][cpu].irq_nr, per_cpu_itv));
+		}
+	}
+
+	if (display_opt(D_IRQ_CPU)) {
+		write_irqcpu_stats(G.st_irqcpu, G.irqcpu_nr,
+				itv,
+				prev, current,
+				prev_str, current_str
+		);
+	}
+
+	if (display_opt(D_SOFTIRQS)) {
+		write_irqcpu_stats(G.st_softirqcpu, G.softirqcpu_nr,
+				itv,
+				prev, current,
+				prev_str, current_str
+		);
+	}
+}
+
+/*
+ * Print the statistics
+ */
+static void write_stats(int current)
+{
+	char prev_time[16];
+	char curr_time[16];
+
+	strftime(prev_time, sizeof(prev_time), "%X", &G.timestamp[!current]);
+	strftime(curr_time, sizeof(curr_time), "%X", &G.timestamp[current]);
+
+	write_stats_core(!current, current, prev_time, curr_time);
+}
+
+static void write_stats_avg(int current)
+{
+	write_stats_core(2, current, "Average:", "Average:");
+}
+
+/*
+ * Read CPU statistics
+ */
+static void get_cpu_statistics(struct stats_cpu *cpu, data_t *up, data_t *up0)
+{
+	FILE *fp;
+	char buf[1024];
+
+	fp = xfopen_for_read(PROCFS_STAT);
+
+	while (fgets(buf, sizeof(buf), fp)) {
+		data_t sum;
+		unsigned cpu_number;
+		struct stats_cpu *cp;
+
+		if (!starts_with_cpu(buf))
+			continue; /* not "cpu" */
+		if (buf[3] == ' ') {
+			/* "cpu " */
+			cp = cpu;
+		} else {
+			/* "cpuN" */
+			if (G.cpu_nr == 0
+			 || sscanf(buf + 3, "%u ", &cpu_number) != 1
+			 || cpu_number >= G.cpu_nr
+			) {
+				continue;
+			}
+			cp = &cpu[cpu_number + 1];
+		}
+
+		/* Read the jiffies, save them */
+		/* Not all fields have to be present */
+		memset(cp, 0, sizeof(*cp));
+		sscanf(skip_non_whitespace(buf + 3),
+			" %"FMT_DATA"u %"FMT_DATA"u %"FMT_DATA"u"
+			" %"FMT_DATA"u %"FMT_DATA"u %"FMT_DATA"u"
+			" %"FMT_DATA"u %"FMT_DATA"u %"FMT_DATA"u",
+			&cp->cpu_user, &cp->cpu_nice, &cp->cpu_system,
+			&cp->cpu_idle, &cp->cpu_iowait, &cp->cpu_irq,
+			&cp->cpu_softirq, &cp->cpu_steal,
+			&cp->cpu_guest
+		);
+		/*
+		 * Compute uptime in jiffies (1/HZ), it'll be the sum of
+		 * individual CPU's uptimes.
+		 * NB: We have to omit cpu_guest, because cpu_user includes it.
+		 */
+		sum = cp->cpu_user + cp->cpu_nice + cp->cpu_system +
+			cp->cpu_idle + cp->cpu_iowait + cp->cpu_irq +
+			cp->cpu_softirq + cp->cpu_steal;
+
+		if (buf[3] == ' ') {
+			/* "cpu " */
+			*up = sum;
+		} else {
+			/* "cpuN" */
+			if (cpu_number == 0 && *up0 != 0) {
+				/* Compute uptime of single CPU */
+				*up0 = sum;
+			}
+		}
+	}
+	fclose(fp);
+}
+
+/*
+ * Read IRQs from /proc/stat
+ */
+static void get_irqs_from_stat(struct stats_irq *irq)
+{
+	FILE *fp;
+	char buf[1024];
+
+	fp = fopen_for_read(PROCFS_STAT);
+	if (!fp)
+		return;
+
+	while (fgets(buf, sizeof(buf), fp)) {
+		if (strncmp(buf, "intr ", 5) == 0)
+			/* Read total number of IRQs since system boot */
+			sscanf(buf + 5, "%"FMT_DATA"u", &irq->irq_nr);
+	}
+
+	fclose(fp);
+}
+
+/*
+ * Read stats from /proc/interrupts or /proc/softirqs
+ */
+static void get_irqs_from_interrupts(const char *fname,
+		struct stats_irqcpu *per_cpu_stats[],
+		int irqs_per_cpu, int current)
+{
+	FILE *fp;
+	struct stats_irq *irq_i;
+	struct stats_irqcpu *ic;
+	char *buf;
+	unsigned buflen;
+	unsigned cpu;
+	unsigned irq;
+	int cpu_index[G.cpu_nr];
+	int iindex;
+	int len, digit;
+
+	for (cpu = 1; cpu <= G.cpu_nr; cpu++) {
+		irq_i = &G.st_irq[current][cpu];
+		irq_i->irq_nr = 0;
+	}
+
+	fp = fopen_for_read(fname);
+	if (!fp)
+		return;
+
+	buflen = INTERRUPTS_LINE + 16 * G.cpu_nr;
+	buf = xmalloc(buflen);
+
+	/* Parse header and determine, which CPUs are online */
+	iindex = 0;
+	while (fgets(buf, buflen, fp)) {
+		char *cp, *next;
+		next = buf;
+		while ((cp = strstr(next, "CPU")) != NULL
+		 && iindex < G.cpu_nr
+		) {
+			cpu = strtoul(cp + 3, &next, 10);
+			cpu_index[iindex++] = cpu;
+		}
+		if (iindex) /* We found header */
+			break;
+	}
+
+	irq = 0;
+	while (fgets(buf, buflen, fp)
+	 && irq < irqs_per_cpu
+	) {
+		char *cp;
+		/* Skip over "<irq>:" */
+		cp = strchr(buf, ':');
+		if (!cp)
+			continue;
+
+		ic = &per_cpu_stats[current][irq];
+		len = cp - buf;
+		if (len > sizeof(ic->irq_name)) {
+			len = sizeof(ic->irq_name);
+		}
+		safe_strncpy(ic->irq_name, buf, len);
+		digit = isdigit(buf[len - 1]);
+		cp++;
+
+		for (cpu = 0; cpu < iindex; cpu++) {
+			char *next;
+			ic = &per_cpu_stats[current][cpu_index[cpu] * irqs_per_cpu + irq];
+			irq_i = &G.st_irq[current][cpu_index[cpu] + 1];
+			ic->interrupt = strtoul(cp, &next, 10);
+			if (digit) {
+				/* Do not count non-numerical IRQs */
+				irq_i->irq_nr += ic->interrupt;
+			}
+			cp = next;
+		}
+		irq++;
+	}
+	fclose(fp);
+	free(buf);
+
+	while (irq < irqs_per_cpu) {
+		/* Number of interrupts per CPU has changed */
+		ic = &per_cpu_stats[current][irq];
+		ic->irq_name[0] = '\0';	/* False interrupt */
+		irq++;
+	}
+}
+
+static void get_uptime(data_t *uptime)
+{
+	FILE *fp;
+	char buf[sizeof(long)*3 * 2 + 4]; /* enough for long.long */
+	unsigned long uptime_sec, decimal;
+
+	fp = fopen_for_read(PROCFS_UPTIME);
+	if (!fp)
+		return;
+	if (fgets(buf, sizeof(buf), fp)) {
+		if (sscanf(buf, "%lu.%lu", &uptime_sec, &decimal) == 2) {
+			*uptime = (data_t)uptime_sec * G.hz + decimal * G.hz / 100;
+		}
+	}
+
+	fclose(fp);
+}
+
+static void get_localtime(struct tm *tm)
+{
+	time_t timer;
+	time(&timer);
+	localtime_r(&timer, tm);
+}
+
+static void alarm_handler(int sig UNUSED_PARAM)
+{
+	signal(SIGALRM, alarm_handler);
+	alarm(G.interval);
+}
+
+static void main_loop(void)
+{
+	unsigned current;
+	unsigned cpus;
+
+	/* Read the stats */
+	if (G.cpu_nr > 1) {
+		G.per_cpu_uptime[0] = 0;
+		get_uptime(&G.per_cpu_uptime[0]);
+	}
+
+	get_cpu_statistics(G.st_cpu[0], &G.global_uptime[0], &G.per_cpu_uptime[0]);
+
+	if (display_opt(D_IRQ_SUM))
+		get_irqs_from_stat(G.st_irq[0]);
+
+	if (display_opt(D_IRQ_SUM | D_IRQ_CPU))
+		get_irqs_from_interrupts(PROCFS_INTERRUPTS, G.st_irqcpu,
+					G.irqcpu_nr, 0);
+
+	if (display_opt(D_SOFTIRQS))
+		get_irqs_from_interrupts(PROCFS_SOFTIRQS, G.st_softirqcpu,
+					G.softirqcpu_nr, 0);
+
+	if (G.interval == 0) {
+		/* Display since boot time */
+		cpus = G.cpu_nr + 1;
+		G.timestamp[1] = G.timestamp[0];
+		memset(G.st_cpu[1], 0, sizeof(G.st_cpu[1][0]) * cpus);
+		memset(G.st_irq[1], 0, sizeof(G.st_irq[1][0]) * cpus);
+		memset(G.st_irqcpu[1], 0, sizeof(G.st_irqcpu[1][0]) * cpus * G.irqcpu_nr);
+		memset(G.st_softirqcpu[1], 0, sizeof(G.st_softirqcpu[1][0]) * cpus * G.softirqcpu_nr);
+
+		write_stats(0);
+
+		/* And we're done */
+		return;
+	}
+
+	/* Set a handler for SIGALRM */
+	alarm_handler(0);
+
+	/* Save the stats we already have. We need them to compute the average */
+	G.timestamp[2] = G.timestamp[0];
+	G.global_uptime[2] = G.global_uptime[0];
+	G.per_cpu_uptime[2] = G.per_cpu_uptime[0];
+	cpus = G.cpu_nr + 1;
+	memcpy(G.st_cpu[2], G.st_cpu[0], sizeof(G.st_cpu[0][0]) * cpus);
+	memcpy(G.st_irq[2], G.st_irq[0], sizeof(G.st_irq[0][0]) * cpus);
+	memcpy(G.st_irqcpu[2], G.st_irqcpu[0], sizeof(G.st_irqcpu[0][0]) * cpus * G.irqcpu_nr);
+	if (display_opt(D_SOFTIRQS)) {
+		memcpy(G.st_softirqcpu[2], G.st_softirqcpu[0],
+			sizeof(G.st_softirqcpu[0][0]) * cpus * G.softirqcpu_nr);
+	}
+
+	current = 1;
+	while (1) {
+		/* Suspend until a signal is received */
+		pause();
+
+		/* Set structures to 0 to distinguish off/online CPUs */
+		memset(&G.st_cpu[current][/*cpu:*/ 1], 0, sizeof(G.st_cpu[0][0]) * G.cpu_nr);
+
+		get_localtime(&G.timestamp[current]);
+
+		/* Read stats */
+		if (G.cpu_nr > 1) {
+			G.per_cpu_uptime[current] = 0;
+			get_uptime(&G.per_cpu_uptime[current]);
+		}
+		get_cpu_statistics(G.st_cpu[current], &G.global_uptime[current], &G.per_cpu_uptime[current]);
+
+		if (display_opt(D_IRQ_SUM))
+			get_irqs_from_stat(G.st_irq[current]);
+
+		if (display_opt(D_IRQ_SUM | D_IRQ_CPU))
+			get_irqs_from_interrupts(PROCFS_INTERRUPTS, G.st_irqcpu,
+					G.irqcpu_nr, current);
+
+		if (display_opt(D_SOFTIRQS))
+			get_irqs_from_interrupts(PROCFS_SOFTIRQS,
+					G.st_softirqcpu,
+					G.softirqcpu_nr, current);
+
+		write_stats(current);
+
+		if (G.count > 0) {
+			if (--G.count == 0)
+				break;
+		}
+
+		current ^= 1;
+	}
+
+	/* Print average statistics */
+	write_stats_avg(current);
+}
+
+/* Initialization */
+
+/* Get number of clock ticks per sec */
+static ALWAYS_INLINE unsigned get_hz(void)
+{
+	return sysconf(_SC_CLK_TCK);
+}
+
+static void alloc_struct(int cpus)
+{
+	int i;
+	for (i = 0; i < 3; i++) {
+		G.st_cpu[i] = xzalloc(sizeof(G.st_cpu[i][0]) * cpus);
+		G.st_irq[i] = xzalloc(sizeof(G.st_irq[i][0]) * cpus);
+		G.st_irqcpu[i] = xzalloc(sizeof(G.st_irqcpu[i][0]) * cpus * G.irqcpu_nr);
+		G.st_softirqcpu[i] = xzalloc(sizeof(G.st_softirqcpu[i][0]) * cpus * G.softirqcpu_nr);
+	}
+	G.cpu_bitmap_len = (cpus >> 3) + 1;
+	G.cpu_bitmap = xzalloc(G.cpu_bitmap_len);
+}
+
+static void print_header(struct tm *t)
+{
+	char cur_date[16];
+	struct utsname uts;
+
+	/* Get system name, release number and hostname */
+	uname(&uts);
+
+	strftime(cur_date, sizeof(cur_date), "%x", t);
+
+	printf("%s %s (%s) \t%s \t_%s_\t(%d CPU)\n",
+		uts.sysname, uts.release, uts.nodename, cur_date, uts.machine, G.cpu_nr);
+}
+
+/*
+ * Get number of processors in /sys
+ */
+static int get_sys_cpu_nr(void)
+{
+	DIR *dir;
+	struct dirent *d;
+	struct stat buf;
+	char line[MAX_PF_NAME];
+	int proc_nr = 0;
+
+	dir = opendir(SYSFS_DEVCPU);
+	if (!dir)
+		return 0;	/* /sys not mounted */
+
+	/* Get current file entry */
+	while ((d = readdir(dir)) != NULL) {
+		if (starts_with_cpu(d->d_name) && isdigit(d->d_name[3])) {
+			snprintf(line, MAX_PF_NAME, "%s/%s", SYSFS_DEVCPU,
+				 d->d_name);
+			line[MAX_PF_NAME - 1] = '\0';
+			/* Get information about file */
+			if (stat(line, &buf) < 0)
+				continue;
+			/* If found 'cpuN', we have one more processor */
+			if (S_ISDIR(buf.st_mode))
+				proc_nr++;
+		}
+	}
+
+	closedir(dir);
+	return proc_nr;
+}
+
+/*
+ * Get number of processors in /proc/stat
+ * Return value '0' means one CPU and non SMP kernel.
+ * Otherwise N means N processor(s) and SMP kernel.
+ */
+static int get_proc_cpu_nr(void)
+{
+	FILE *fp;
+	char line[256];
+	int proc_nr = -1;
+
+	fp = xfopen_for_read(PROCFS_STAT);
+	while (fgets(line, sizeof(line), fp)) {
+		if (!starts_with_cpu(line)) {
+			if (proc_nr >= 0)
+				break; /* we are past "cpuN..." lines */
+			continue;
+		}
+		if (line[3] != ' ') { /* "cpuN" */
+			int num_proc;
+			if (sscanf(line + 3, "%u", &num_proc) == 1
+			 && num_proc > proc_nr
+			) {
+				proc_nr = num_proc;
+			}
+		}
+	}
+
+	fclose(fp);
+	return proc_nr + 1;
+}
+
+static int get_cpu_nr(void)
+{
+	int n;
+
+	/* Try to use /sys, if possible */
+	n = get_sys_cpu_nr();
+	if (n == 0)
+		/* Otherwise use /proc/stat */
+		n = get_proc_cpu_nr();
+
+	return n;
+}
+
+/*
+ * Get number of interrupts available per processor
+ */
+static int get_irqcpu_nr(const char *f, int max_irqs)
+{
+	FILE *fp;
+	char *line;
+	unsigned linelen;
+	unsigned irq;
+
+	fp = fopen_for_read(f);
+	if (!fp)		/* No interrupts file */
+		return 0;
+
+	linelen = INTERRUPTS_LINE + 16 * G.cpu_nr;
+	line = xmalloc(linelen);
+
+	irq = 0;
+	while (fgets(line, linelen, fp)
+	 && irq < max_irqs
+	) {
+		int p = strcspn(line, ":");
+		if ((p > 0) && (p < 16))
+			irq++;
+	}
+
+	fclose(fp);
+	free(line);
+
+	return irq;
+}
+
+//usage:#define mpstat_trivial_usage
+//usage:       "[-A] [-I SUM|CPU|ALL|SCPU] [-u] [-P num|ALL] [INTERVAL [COUNT]]"
+//usage:#define mpstat_full_usage "\n\n"
+//usage:       "Per-processor statistics\n"
+//usage:     "\nOptions:"
+//usage:     "\n	-A			Same as -I ALL -u -P ALL"
+//usage:     "\n	-I SUM|CPU|ALL|SCPU	Report interrupt statistics"
+//usage:     "\n	-P num|ALL		Processor to monitor"
+//usage:     "\n	-u			Report CPU utilization"
+
+int mpstat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int mpstat_main(int UNUSED_PARAM argc, char **argv)
+{
+	char *opt_irq_fmt;
+	char *opt_set_cpu;
+	int i, opt;
+	enum {
+		OPT_ALL    = 1 << 0,	/* -A */
+		OPT_INTS   = 1 << 1,	/* -I */
+		OPT_SETCPU = 1 << 2,	/* -P */
+		OPT_UTIL   = 1 << 3,	/* -u */
+	};
+
+	/* Dont buffer data if redirected to a pipe */
+	setbuf(stdout, NULL);
+
+	INIT_G();
+
+	G.interval = -1;
+
+	/* Get number of processors */
+	G.cpu_nr = get_cpu_nr();
+
+	/* Get number of clock ticks per sec */
+	G.hz = get_hz();
+
+	/* Calculate number of interrupts per processor */
+	G.irqcpu_nr = get_irqcpu_nr(PROCFS_INTERRUPTS, NR_IRQS) + NR_IRQCPU_PREALLOC;
+
+	/* Calculate number of soft interrupts per processor */
+	G.softirqcpu_nr = get_irqcpu_nr(PROCFS_SOFTIRQS, NR_IRQS) + NR_IRQCPU_PREALLOC;
+
+	/* Allocate space for structures. + 1 for global structure. */
+	alloc_struct(G.cpu_nr + 1);
+
+	/* Parse and process arguments */
+	opt = getopt32(argv, "AI:P:u", &opt_irq_fmt, &opt_set_cpu);
+	argv += optind;
+
+	if (*argv) {
+		/* Get interval */
+		G.interval = xatoi_u(*argv);
+		G.count = -1;
+		argv++;
+		if (*argv) {
+			/* Get count value */
+			if (G.interval == 0)
+				bb_show_usage();
+			G.count = xatoi_u(*argv);
+			//if (*++argv)
+			//	bb_show_usage();
+		}
+	}
+	if (G.interval < 0)
+		G.interval = 0;
+
+	if (opt & OPT_ALL) {
+		G.p_option = 1;
+		G.options |= D_CPU + D_IRQ_SUM + D_IRQ_CPU + D_SOFTIRQS;
+		/* Select every CPU */
+		memset(G.cpu_bitmap, 0xff, G.cpu_bitmap_len);
+	}
+
+	if (opt & OPT_INTS) {
+		if (strcmp(opt_irq_fmt, "ALL") == 0)
+			G.options |= D_IRQ_SUM + D_IRQ_CPU + D_SOFTIRQS;
+		else if (strcmp(opt_irq_fmt, "CPU") == 0)
+			G.options |= D_IRQ_CPU;
+		else if (strcmp(opt_irq_fmt, "SUM") == 0)
+			G.options |= D_IRQ_SUM;
+		else if (strcmp(opt_irq_fmt, "SCPU") == 0)
+			G.options |= D_SOFTIRQS;
+		else
+			bb_show_usage();
+	}
+
+	if ((opt & OPT_UTIL) /* -u? */
+	 || G.options == 0  /* nothing? (use default then) */
+	) {
+		G.options |= D_CPU;
+	}
+
+	if (opt & OPT_SETCPU) {
+		char *t;
+		G.p_option = 1;
+
+		for (t = strtok(opt_set_cpu, ","); t; t = strtok(NULL, ",")) {
+			if (strcmp(t, "ALL") == 0) {
+				/* Select every CPU */
+				memset(G.cpu_bitmap, 0xff, G.cpu_bitmap_len);
+			} else {
+				/* Get CPU number */
+				unsigned n = xatoi_u(t);
+				if (n >= G.cpu_nr)
+					bb_error_msg_and_die("not that many processors");
+				n++;
+				G.cpu_bitmap[n >> 3] |= 1 << (n & 7);
+			}
+		}
+	}
+
+	if (!G.p_option)
+		/* Display global stats */
+		G.cpu_bitmap[0] = 1;
+
+	/* Get time */
+	get_localtime(&G.timestamp[0]);
+
+	/* Display header */
+	print_header(&G.timestamp[0]);
+
+	/* The main loop */
+	main_loop();
+
+	if (ENABLE_FEATURE_CLEAN_UP) {
+		/* Clean up */
+		for (i = 0; i < 3; i++) {
+			free(G.st_cpu[i]);
+			free(G.st_irq[i]);
+			free(G.st_irqcpu[i]);
+			free(G.st_softirqcpu[i]);
+		}
+		free(G.cpu_bitmap);
+		free(&G);
+	}
+
+	return EXIT_SUCCESS;
+}