linuxcpu使用率怎么看（Linux中计算特定CPU使用率案例详解）

Total CPU time since boot = user+nice+system+idle+iowait+irq+softirq+steal Total CPU Idle time since boot = idle + iowait Total CPU usage time since boot = Total CPU time since boot-Total CPU Idle time since boot Total CPU percentage = Total CPU usage time since boot/Total CPU time since boot * 100%

#!/bin/bash # by Paul Colby (http://colby.id.au), no rights reserved ;) PREV_TOTAL=0 PREV_IDLE=0 while true; do # Get the total CPU statistics, discarding the cpu prefix. CPU=(`sed -n s/^cpu\s//p /proc/stat`) IDLE=${CPU[3]} # Just the idle CPU time. # Calculate the total CPU time. TOTAL=0 for VALUE in "${CPU[@]}"; do let "TOTAL=$TOTAL+$VALUE" done # Calculate the CPU usage since we last checked. let "DIFF_IDLE=$IDLE-$PREV_IDLE" let "DIFF_TOTAL=$TOTAL-$PREV_TOTAL" let "DIFF_USAGE=(1000*($DIFF_TOTAL-$DIFF_IDLE)/$DIFF_TOTAL+5)/10" echo -en "\rCPU: $DIFF_USAGE% \b\b" # Remember the total and idle CPU times for the next check. PREV_TOTAL="$TOTAL" PREV_IDLE="$IDLE" # Wait before checking again. sleep 1 done

附注：内核版本3.14.69，文件为 /fs/proc/stat.c #include <linux/cpumask.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/kernel_stat.h> #include <linux/proc_fs.h> #include <linux/sched.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/time.h> #include <linux/irqnr.h> #include <asm/cputime.h> #include <linux/tick.h> #ifndef arch_irq_stat_cpu #define arch_irq_stat_cpu(cpu) 0 #endif #ifndef arch_irq_stat #define arch_irq_stat() 0 #endif #ifdef arch_idle_time static cputime64_t get_idle_time(int cpu) { cputime64_t idle; idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]; if (cpu_online(cpu) && !nr_iowait_cpu(cpu)) idle += arch_idle_time(cpu); return idle; } static cputime64_t get_iowait_time(int cpu) { cputime64_t iowait; iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]; if (cpu_online(cpu) && nr_iowait_cpu(cpu)) iowait += arch_idle_time(cpu); return iowait; } #else static u64 get_idle_time(int cpu) { u64 idle, idle_time = -1ULL; if (cpu_online(cpu)) idle_time = get_cpu_idle_time_us(cpu, NULL); if (idle_time == -1ULL) /* !NO_HZ or cpu offline so we can rely on cpustat.idle */ idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE]; else idle = usecs_to_cputime64(idle_time); return idle; } static u64 get_iowait_time(int cpu) { u64 iowait, iowait_time = -1ULL; if (cpu_online(cpu)) iowait_time = get_cpu_iowait_time_us(cpu, NULL); if (iowait_time == -1ULL) /* !NO_HZ or cpu offline so we can rely on cpustat.iowait */ iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]; else iowait = usecs_to_cputime64(iowait_time); return iowait; } #endif static int show_stat(struct seq_file *p, void *v) { int i, j; unsigned long jif; u64 user, nice, system, idle, iowait, irq, softirq, steal; u64 guest, guest_nice; u64 sum = 0; u64 sum_softirq = 0; unsigned int per_softirq_sums[NR_SOFTIRQS] = {0}; struct timespec boottime; user = nice = system = idle = iowait = irq = softirq = steal = 0; guest = guest_nice = 0; getboottime(&boottime); jif = boottime.tv_sec; for_each_possible_cpu(i) { user += kcpustat_cpu(i).cpustat[CPUTIME_USER]; nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE]; system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]; idle += get_idle_time(i); iowait += get_iowait_time(i); irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ]; softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]; steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; sum += kstat_cpu_irqs_sum(i); sum += arch_irq_stat_cpu(i); for (j = 0; j < NR_SOFTIRQS; j++) { unsigned int softirq_stat = kstat_softirqs_cpu(j, i); per_softirq_sums[j] += softirq_stat; sum_softirq += softirq_stat; } } sum += arch_irq_stat(); seq_puts(p, "cpu "); seq_put_decimal_ull(p, , cputime64_to_clock_t(user)); seq_put_decimal_ull(p, , cputime64_to_clock_t(nice)); seq_put_decimal_ull(p, , cputime64_to_clock_t(system)); seq_put_decimal_ull(p, , cputime64_to_clock_t(idle)); seq_put_decimal_ull(p, , cputime64_to_clock_t(iowait)); seq_put_decimal_ull(p, , cputime64_to_clock_t(irq)); seq_put_decimal_ull(p, , cputime64_to_clock_t(softirq)); seq_put_decimal_ull(p, , cputime64_to_clock_t(steal)); seq_put_decimal_ull(p, , cputime64_to_clock_t(guest)); seq_put_decimal_ull(p, , cputime64_to_clock_t(guest_nice)); seq_putc(p, \n); for_each_online_cpu(i) { /* Copy values here to work around gcc-2.95.3, gcc-2.96 */ user = kcpustat_cpu(i).cpustat[CPUTIME_USER]; nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE]; system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]; idle = get_idle_time(i); iowait = get_iowait_time(i); irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ]; softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]; steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; seq_printf(p, "cpu%d", i); seq_put_decimal_ull(p, , cputime64_to_clock_t(user)); seq_put_decimal_ull(p, , cputime64_to_clock_t(nice)); seq_put_decimal_ull(p, , cputime64_to_clock_t(system)); seq_put_decimal_ull(p, , cputime64_to_clock_t(idle)); seq_put_decimal_ull(p, , cputime64_to_clock_t(iowait)); seq_put_decimal_ull(p, , cputime64_to_clock_t(irq)); seq_put_decimal_ull(p, , cputime64_to_clock_t(softirq)); seq_put_decimal_ull(p, , cputime64_to_clock_t(steal)); seq_put_decimal_ull(p, , cputime64_to_clock_t(guest)); seq_put_decimal_ull(p, , cputime64_to_clock_t(guest_nice)); seq_putc(p, \n); } seq_printf(p, "intr %llu", (unsigned long long)sum); /* sum again ? it could be updated? */ for_each_irq_nr(j) seq_put_decimal_ull(p, , kstat_irqs_usr(j)); seq_printf(p, "\nctxt %llu\n" "btime %lu\n" "processes %lu\n" "procs_running %lu\n" "procs_blocked %lu\n", nr_context_switches(), (unsigned long)jif, total_forks, nr_running(), nr_iowait()); seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq); for (i = 0; i < NR_SOFTIRQS; i++) seq_put_decimal_ull(p, , per_softirq_sums[i]); seq_putc(p, \n); return 0; } static int stat_open(struct inode *inode, struct file *file) { size_t size = 1024 + 128 * num_possible_cpus(); char *buf; struct seq_file *m; int res; /* minimum size to display an interrupt count : 2 bytes */ size += 2 * nr_irqs; /* dont ask for more than the kmalloc() max size */ if (size > KMALLOC_MAX_SIZE) size = KMALLOC_MAX_SIZE; buf = kmalloc(size, GFP_KERNEL); if (!buf) return -ENOMEM; res = single_open(file, show_stat, NULL); if (!res) { m = file->private_data; m->buf = buf; m->size = ksize(buf); } else kfree(buf); return res; } static const struct file_operations proc_stat_operations = { .open = stat_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static int __init proc_stat_init(void) { proc_create("stat", 0, NULL, &proc_stat_operations); return 0; } fs_initcall(proc_stat_init);

声明：本站所有文章，如无特殊说明或标注，均为本站原创发布。任何个人或组织，在未征得本站同意时，禁止复制、盗用、采集、发布本站内容到任何网站、书籍等各类媒体平台。如若本站内容侵犯了原著者的合法权益，可联系我们进行处理。