Re-write CPU usage calculation to avoid sleep in AJAX call

2 files changed, 47 insertions, 42 deletions

diff --git a/src/usr/local/www/includes/functions.inc.php b/src/usr/local/www/includes/functions.inc.php
index 43723a3..664ea24 100644
--- a/src/usr/local/www/includes/functions.inc.php
+++ b/src/usr/local/www/includes/functions.inc.php
@@ -79,29 +79,13 @@ function get_uptime() {
 	return $uptimestr;
 }
 
-/* Calculates non-idle CPU time and returns as a percentage */
+// Returns the current total ticks and user ticks. The dashboard widget calculates the load from that
 function cpu_usage() {
-	$duration = 1;
+
 	$diff = array('user', 'nice', 'sys', 'intr', 'idle');
 	$cpuTicks = array_combine($diff, explode(" ", get_single_sysctl('kern.cp_time')));
-	sleep($duration);
-	$cpuTicks2 = array_combine($diff, explode(" ", get_single_sysctl('kern.cp_time')));
-
-	$totalStart = array_sum($cpuTicks);
-	$totalEnd = array_sum($cpuTicks2);
-
-	// Something wrapped ?!?!
-	if ($totalEnd <= $totalStart) {
-		return 0;
-	}
-
-	// Calculate total cycles used
-	$totalUsed = ($totalEnd - $totalStart) - ($cpuTicks2['idle'] - $cpuTicks['idle']);
-
-	// Calculate the percentage used
-	$cpuUsage = floor(100 * ($totalUsed / ($totalEnd - $totalStart)));
 
-	return $cpuUsage;
+	return array_sum($cpuTicks) . "|" . $cpuTicks['idle'];
 }
 
 function get_pfstate($percent=false) {
diff --git a/src/usr/local/www/widgets/widgets/system_information.widget.php b/src/usr/local/www/widgets/widgets/system_information.widget.php
index 8249ebd..ae38c56 100644
--- a/src/usr/local/www/widgets/widgets/system_information.widget.php
+++ b/src/usr/local/www/widgets/widgets/system_information.widget.php
@@ -389,7 +389,7 @@ $rows_displayed = false;
 					</div>
 				</div>
 				<?php $update_period = (!empty($config['widgets']['period'])) ? $config['widgets']['period'] : "10"; ?>
-				<span id="cpumeter"><?=sprintf(gettext("Updating in %s seconds"), $update_period)?></span>
+				<span id="cpumeter"><?=sprintf(gettext("Retrieving CPU data %s"), "<i class=\"fa fa-gear fa-spin\"></i>")?></span>
 			</td>
 		</tr>
 <?php
@@ -508,7 +508,8 @@ $rows_displayed = false;
 //<![CDATA[
 <?php if ($widget_first_instance): ?>
 
-var update_interval = "<?=$widgetperiod?>";
+var lastTotal = 0;
+var lastUsed = 0;
 
 function setProgress(barName, percent) {
 	$('[id="' + barName + '"]').css('width', percent + '%').attr('aria-valuenow', percent);
@@ -523,17 +524,23 @@ function stats(x) {
 			return false;
 	}))
 
-	updateUptime(values[2]);
-	updateDateTime(values[5]);
-	updateCPU(values[0]);
-	updateMemory(values[1]);
-	updateState(values[3]);
-	updateTemp(values[4]);
-	updateCpuFreq(values[6]);
-	updateLoadAverage(values[7]);
-	updateMbuf(values[8]);
-	updateMbufMeter(values[9]);
-	updateStateMeter(values[10]);
+	if (lastTotal === 0) {
+		lastTotal = values[0];
+		lastUsed = values[1];
+	} else {
+		updateCPU(values[0], values[1]);
+	}
+
+	updateUptime(values[3]);
+	updateDateTime(values[6]);
+	updateMemory(values[2]);
+	updateState(values[4]);
+	updateTemp(values[5]);
+	updateCpuFreq(values[7]);
+	updateLoadAverage(values[8]);
+	updateMbuf(values[9]);
+	updateMbufMeter(values[10]);
+	updateStateMeter(values[11]);
 }
 
 function updateMemory(x) {
@@ -560,19 +567,33 @@ function updateMbufMeter(x) {
 	}
 }
 
-function updateCPU(x) {
+function updateCPU(total, used) {
 
-	if ($('#cpumeter')) {
-		$('[id="cpumeter"]').html(x + '%');
-	}
-	if ($('#cpuPB')) {
-		setProgress('cpuPB', parseInt(x));
-	}
+	// Just in case it wraps
+	if ((lastTotal <= total) && (lastUsed <= used)) {
+		// Calculate the total ticks and the used ticks sine the last time it was checked
+		var d_total = total - lastTotal;
+		var d_used = used - lastUsed;
+
+		// Convert to percent
+		var x = Math.trunc( ((d_total - d_used)/d_total) * 100);
 
-	/* Load CPU Graph widget if enabled */
-	if (widgetActive('cpu_graphs')) {
-		GraphValue(graph[0], x);
+		if ($('#cpumeter')) {
+			$('[id="cpumeter"]').html(x + '%');
+		}
+
+		if ($('#cpuPB')) {
+			setProgress('cpuPB', parseInt(x));
+		}
+
+		/* Load CPU Graph widget if enabled */
+		if (widgetActive('cpu_graphs')) {
+			GraphValue(graph[0], x);
+		}
 	}
+
+	lastTotal = total;
+	lastUsed = used;
 }
 
 function updateTemp(x) {