From 8d6c9e9b248e4f583ed40bbcb4d923d2d2048ed3 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Thomas=20P=C3=A9rennou=20=28Viveris=20Technologie=29?=
 <thomas.perennou@external.thalesgroup.com>
Date: Wed, 18 Feb 2015 17:23:47 +0100
Subject: [PATCH] cpumon_light reimplementation to avoid fork

---
 master/root/bin/cpumon_light | 50 ++++++++++++++++++++++++------------
 1 file changed, 33 insertions(+), 17 deletions(-)

diff --git a/master/root/bin/cpumon_light b/master/root/bin/cpumon_light
index e450952..af635c1 100755
--- a/master/root/bin/cpumon_light
+++ b/master/root/bin/cpumon_light
@@ -1,20 +1,36 @@
-#!/bin/sh
+#!/usr/bin/perl
 
-INSTALL_DIR=$(dirname $0)
+use strict;
 
-$INSTALL_DIR/monitor_proc -s /proc/stat
-while true; do
-	sleep 1
-	$INSTALL_DIR/monitor_proc /proc/stat | \
-		awk '
-BEGIN { printf "cpu:" }
-/cpu[0-9]/ {
-	idle=$5
-	sum=0; for (i=2;i<=NF;i++) sum+=$(i)
-	load=(sum-idle)*100/sum
-	tot+=load
-	if (!not_first) not_first=1; else printf " +"
-    	printf " % 5.1f%%", load
+my @cpu_stat_t0 = proc_stat();
+sleep 1;
+my @cpu_stat_t1 = proc_stat();
+my $total = 0;
+for (my $cpu_i = 0; $cpu_i < (scalar @cpu_stat_t0); $cpu_i++) {
+    my @stat_t0 = split /\s+/, $cpu_stat_t0[$cpu_i];
+    my @stat_t1 = split /\s+/, $cpu_stat_t1[$cpu_i];
+    my ($t0_idle, $t1_idle) = ($stat_t0[3], $stat_t1[3]);
+    my ($t0_total, $t1_total) = (0, 0);
+    $t0_total += $_ foreach @stat_t0;
+    $t1_total += $_ foreach @stat_t1;
+
+    my $load = ($t1_total - $t0_total == 0) ? 100:
+        int((100 * (($t1_total - $t0_total) - ($t1_idle - $t0_idle))/($t1_total - $t0_total)) + 0.5);
+    print " +" unless ($cpu_i == 0);
+    printf "% 5.1f%% ", $load;
+    $total += $load;
+}
+printf " = % 6.1f%%\n", $total;
+
+sub proc_stat() {
+    return grep {s/^cpu\d+\s//} read_file('/proc/stat');
 }
-END { printf " = % 6.1f%%\n", tot }'
-done
+
+sub read_file($) {
+    my ($file) = @_;
+    open FILE, "<$file";
+    my @content = <FILE>;
+    close FILE;
+    return @content;
+}
+
-- 
2.30.2