itop更方便的了解Linux下中断情况
通过itop工具了解系统中每秒多少中断发生，发生在哪个CPU上。
Linux下中断来源可以从 /proc/interrupts 中了解到:
$ cat /proc/interrupts
CPU0 CPU1
0: 247701 250313 IO-APIC-edge timer
1: 501 567 IO-APIC-edge i8042
3: 1 1 IO-APIC-edge
8: 1 0 IO-APIC-edge rtc0
9: 256 240 IO-APIC-fasteoi acpi
12: 1134 1149 IO-APIC-edge i8042
16: 629 554 IO-APIC-fasteoi nvidia
17: 21313 20869 IO-APIC-fasteoi firewire_ohci, eth1
18: 0 0 IO-APIC-fasteoi mmc0
19: 51822 50079 IO-APIC-fasteoi ata_piix, ata_piix
20: 5605 5255 IO-APIC-fasteoi ehci_hcd:usb2, uhci_hcd:usb3, uhci_hcd:usb6
21: 0 0 IO-APIC-fasteoi uhci_hcd:usb4, uhci_hcd:usb7
22: 33 33 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb5, uhci_hcd:usb8
45: 337 247 PCI-MSI-edge eth0
46: 441 447 PCI-MSI-edge hda_intel
NMI: 0 0 Non-maskable interrupts
LOC: 169176 174899 Local timer interrupts
SPU: 0 0 Spurious interrupts
PMI: 0 0 Performance monitoring interrupts
PND: 0 0 Performance pending work
RES: 42289 40236 Rescheduling interrupts
CAL: 154 1076 Function call interrupts
TLB: 5838 5365 TLB shootdowns
TRM: 0 0 Thermal event interrupts
THR: 0 0 Threshold APIC interrupts
MCE: 0 0 Machine check exceptions
MCP: 5 5 Machine check polls
ERR: 1
MIS: 0
软中断可以从/proc/softirqs 了解到:
$ cat /proc/softirqs
CPU0 CPU1
HI: 0 0
TIMER: 160508 1170976
NET_TX: 2 2
NET_RX: 3303 3165
BLOCK: 50964 49198
BLOCK_IOPOLL: 0 0
TASKLET: 24743 24284
SCHED: 39483 41848
HRTIMER: 34 40
RCU: 92193 92592
总的中断次数可以从vmstat或者dstat了解到:
$ vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 3 0 0 44160 327144 876600 0 0 894 584 458 2295 11 5 70 15
itop提供了更方便的方式了解,作者Hunz在源码里面写:
It’s quite simple but it does its job.
虽然简单,但是适用:
Ubutun下可以这样安装: apt-get install itop
$ itop INT NAME RATE MAX 0 [PIC-edge time] 628 Ints/s (max: 628) 1 [PIC-edge i804] 4 Ints/s (max: 4) 17 [PIC-fasteoi fire] 8 Ints/s (max: 22) 19 [PIC-fasteoi ata_] 1 Ints/s (max: 14) 20 [PIC-fasteoi ehci] 25 Ints/s (max: 25) 45 [MSI-edge eth0] 1 Ints/s (max: 1)
他会计算每秒每个中断源中断的次数,看起来比较方便.
itop 程序代码 (redhat)
#!/usr/bin/perl
#
# Interrupt top
#
# Show the interrupts per second/per IRQ per CPU
# Parse /proc/interrupts file for data
#
# CPU0 CPU1
# 0: 3025267376 3026744388 IO-APIC-edge timer
# 1: 833854 843315 IO-APIC-edge i8042
# 6: 15 63 IO-APIC-edge floppy
# 7: 0 0 IO-APIC-edge parport0
# 8: 532620 522911 IO-APIC-edge rtc
# 9: 1 0 IO-APIC-level acpi
# 12: 9812189 9981980 IO-APIC-edge i8042
# 14: 27181914 27208373 IO-APIC-edge ide0
# 58: 249517917 0 IO-APIC-level eth0
# 66: 1090230 1089904 IO-APIC-level ehci_hcd:usb1, uhci_hcd:usb2
# 169: 82497 85243 IO-APIC-level HDA Intel, uhci_hcd:usb5, i915@pci:0000:00:02.0
# 217: 0 0 IO-APIC-level uhci_hcd:usb4
# 233: 2809674 2795397 IO-APIC-level libata, uhci_hcd:usb3
# NMI: 0 0
# LOC: 1754237653 1754237661
# ERR: 0
# MIS: 0
use IO::File;
use Term::Cap;
$term = Tgetent Term::Cap;
print $term->Tputs('cl');
$fh = new IO::File;
if (!$fh->open("</proc/interrupts")) {
die "Unable to open /proc/interrupts";
}
$top = $fh->getpos();
$first_time = 0;
while (1) {
$fh->setpos($top);
# Read and parse interrupts
$header = <$fh>; # Header line
# Count CPUs
$cpus = () = $header =~ /CPU/g;
my %irqs;
while (<$fh>) {
#if (/^\s*(\d+):(\s*(\d+)\s*)*(\S+)\s*(.*)$/) {
if (/^\s*(\d+):\s*(\d+)\s+(\S+)\s+(.*)$/) {
# Found a IRQ line, Build an assoc array of CPU values
#print $1 . ":" . $2 .":". $3 .":". $4 .":". $5 .":". $6 . ":" . $7 .":". $8 .":". $9 . "\n";
$irq = $1;
for ($cpu = 0; $cpu < $cpus; $cpu++) {
$exp = '$icount = $' . ($cpu + 2);
eval $exp;
$irqs{$irq}[$cpu] = $icount
}
eval '$desc = $' . ($cpus + 2);
$desc =~ /(\S+)\s+(.*)$/;
$irq_type{$irq} = $1;
$irq_device{$irq} = $2;
#eval '$irq_type{$irq} = $' . ($cpus + 2);
#print $irq_type{$irq} . "\n";
#eval '$irq_device{$irq} = $' . ($cpus + 3);
}
}
if ($first_time != 0) {
# Prepare sceeen
print $term->Tputs('ho');
# Output header
printf("%28s%" . ($cpus + 1) * 16 . "s", "", "IRQs/Second\n");
printf('%20s (%3s) ', "Device", "IRQ");
foreach ($cpu = 0; $cpu < $cpus; $cpu++) {
printf('%15s ', 'CPU' . $cpu);
}
printf("%15s\n", "TOTAL");
foreach $irq (keys %irqs) {
printf('%20s (%3d): ', substr($irq_device{$irq}, 0, 20), $irq);
$total = 0;
for ($cpu = 0; $cpu < 2; $cpu ++) {
printf("%15s ", $irqs{$irq}[$cpu] - $last{$irq}[$cpu]);
$total += $irqs{$irq}[$cpu] - $last{$irq}[$cpu];
}
printf("%15s\n", $total);
}
}
$first_time = 1;
%last = %irqs;
sleep 1;
}