#!/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;
}