optimization fsStats, disksIO, networkStats

CHANGELOG.md

@@ -89,6 +89,7 @@ Other changes
 
 | Version        | Date           | Comment  |
 | -------------- | -------------- | -------- |
+| 3.10.1         | 2016-11-14     | optimization fsStats, disksIO, networkStats |
 | 3.10.0         | 2016-11-12     | added blockDevices, fixed fsSize, added file system type |
 | 3.9.0          | 2016-11-11     | added MAC address to networkInterfaces, fixed currentLoad |
 | 3.8.1          | 2016-11-04     | updated docs |

lib/filesystem.js

@@ -132,6 +132,49 @@ exports.blockDevices = blockDevices;
 // --------------------------
 // FS - speed
 
+function calcFsSpeed(rx, wx) {
+  let result = {
+    rx: 0,
+    wx: 0,
+    tx: 0,
+    rx_sec: -1,
+    wx_sec: -1,
+    tx_sec: -1,
+    ms: 0
+  };
+
+  if (_fs_speed && _fs_speed.ms) {
+    result.rx = rx;
+    result.wx = wx;
+    result.tx = result.rx + result.wx;
+    result.ms = Date.now() - _fs_speed.ms;
+    result.rx_sec = (result.rx - _fs_speed.bytes_read) / (result.ms / 1000);
+    result.wx_sec = (result.wx - _fs_speed.bytes_write) / (result.ms / 1000);
+    result.tx_sec = result.rx_sec + result.wx_sec;
+    _fs_speed.rx_sec = result.rx_sec;
+    _fs_speed.wx_sec = result.wx_sec;
+    _fs_speed.tx_sec = result.tx_sec;
+    _fs_speed.bytes_read = result.rx;
+    _fs_speed.bytes_write = result.wx;
+    _fs_speed.bytes_overall = result.rx + result.wx;
+    _fs_speed.ms = Date.now();
+    _fs_speed.last_ms = result.ms;
+  } else {
+    result.rx = rx;
+    result.wx = wx;
+    result.tx = result.rx + result.wx;
+    _fs_speed.rx_sec = -1;
+    _fs_speed.wx_sec = -1;
+    _fs_speed.tx_sec = -1;
+    _fs_speed.bytes_read = result.rx;
+    _fs_speed.bytes_write = result.wx;
+    _fs_speed.bytes_overall = result.rx + result.wx;
+    _fs_speed.ms = Date.now();
+    _fs_speed.last_ms = 0;
+  }
+  return result;
+}
+
 function fsStats(callback) {
 
   return new Promise((resolve, reject) => {
@@ -142,7 +185,7 @@ function fsStats(callback) {
         reject(error);
       }
 
-      var result = {
+      let result = {
         rx: 0,
         wx: 0,
         tx: 0,
@@ -152,89 +195,75 @@ function fsStats(callback) {
         ms: 0
       };
 
-      if (_linux) {
+      let rx = 0;
-//		exec("df -k | grep /dev/", function(error, stdout) {
+      let wx = 0;
-        exec("lsblk | grep /", function (error, stdout) {
+      if ((_fs_speed && !_fs_speed.ms) || (_fs_speed && _fs_speed.ms && Date.now() - _fs_speed.ms >= 500)) {
-          if (!error) {
+        if (_linux) {
-            let lines = stdout.toString().split('\n');
+//  		  exec("df -k | grep /dev/", function(error, stdout) {
-            let fs_filter = [];
+          exec("lsblk | grep /", function (error, stdout) {
-            lines.forEach(function (line) {
+            if (!error) {
-              if (line != '') {
+              let lines = stdout.toString().split('\n');
-                line = line.replace(/[├─│└]+/g, "").trim().split(' ');
+              let fs_filter = [];
-                if (fs_filter.indexOf(line[0]) == -1) fs_filter.push(line[0])
+              lines.forEach(function (line) {
-              }
+                if (line != '') {
-            });
+                  line = line.replace(/[├─│└]+/g, "").trim().split(' ');
-
+                  if (fs_filter.indexOf(line[0]) == -1) fs_filter.push(line[0])
-            let output = fs_filter.join('|');
-            exec("cat /proc/diskstats | egrep '" + output + "'", function (error, stdout) {
-              if (!error) {
-                let lines = stdout.toString().split('\n');
-                lines.forEach(function (line) {
-                  line = line.trim();
-                  if (line != '') {
-                    line = line.replace(/ +/g, " ").split(' ');
-
-                    result.rx += parseInt(line[5]) * 512;
-                    result.wx += parseInt(line[9]) * 512;
-                  }
-                });
-                result.tx = result.rx + result.wx;
-                if (_fs_speed && _fs_speed.ms) {
-                  result.ms = Date.now() - _fs_speed.ms;
-                  result.rx_sec = (result.rx - _fs_speed.bytes_read) / (result.ms / 1000);
-                  result.wx_sec = (result.wx - _fs_speed.bytes_write) / (result.ms / 1000);
-                  result.tx_sec = result.rx_sec + result.wx_sec;
-                } else {
-                  result.rx_sec = -1;
-                  result.wx_sec = -1;
-                  result.tx_sec = -1;
                 }
-                _fs_speed.bytes_read = result.rx;
+              });
-                _fs_speed.bytes_write = result.wx;
+
-                _fs_speed.bytes_overall = result.rx + result.wx;
+              let output = fs_filter.join('|');
-                _fs_speed.ms = Date.now();
+              exec("cat /proc/diskstats | egrep '" + output + "'", function (error, stdout) {
-              }
+                if (!error) {
+                  let lines = stdout.toString().split('\n');
+                  lines.forEach(function (line) {
+                    line = line.trim();
+                    if (line != '') {
+                      line = line.replace(/ +/g, " ").split(' ');
+
+                      rx += parseInt(line[5]) * 512;
+                      wx += parseInt(line[9]) * 512;
+                    }
+                  });
+                  result = calcFsSpeed(rx, wx);
+                }
+                if (callback) { callback(result) }
+                resolve(result);
+              })
+            } else {
               if (callback) { callback(result) }
               resolve(result);
-            })
+            }
-          } else {
+          })
+        }
+        if (_darwin) {
+          exec("ioreg -c IOBlockStorageDriver -k Statistics -r -w0 | sed -n '/IOBlockStorageDriver/,/Statistics/p' | grep 'Statistics' | tr -cd '01234567890,\n' | awk -F',' '{print $3, $10}'", function (error, stdout) {
+            if (!error) {
+              let lines = stdout.toString().split('\n');
+              lines.forEach(function (line) {
+                line = line.trim();
+                if (line != '') {
+                  line = line.split(' ');
+
+                  rx += parseInt(line[0]);
+                  wx += parseInt(line[1]);
+                }
+              });
+              result = calcFsSpeed(rx, wx);
+            }
             if (callback) { callback(result) }
             resolve(result);
-          }
+          })
-        })
+        }
-      }
+      } else {
-      if (_darwin) {
+        result.ms = _fs_speed.last_ms;
-        exec("ioreg -c IOBlockStorageDriver -k Statistics -r -w0 | sed -n '/IOBlockStorageDriver/,/Statistics/p' | grep 'Statistics' | tr -cd '01234567890,\n' | awk -F',' '{print $3, $10}'", function (error, stdout) {
+        result.rx = _fs_speed.bytes_read;
-          if (!error) {
+        result.wx = _fs_speed.bytes_write;
-            let lines = stdout.toString().split('\n');
+        result.tx = _fs_speed.bytes_read + _fs_speed.bytes_write;
-            lines.forEach(function (line) {
+        result.rx_sec = _fs_speed.rx_sec;
-              line = line.trim();
+        result.wx_sec = _fs_speed.wx_sec;
-              if (line != '') {
+        result.tx_sec = _fs_speed.tx_sec;
-                line = line.split(' ');
+        if (callback) { callback(result) }
-
+        resolve(result);
-                result.rx += parseInt(line[0]);
-                result.wx += parseInt(line[1]);
-              }
-            });
-            result.tx = result.rx + result.wx;
-            if (_fs_speed && _fs_speed.ms) {
-              result.ms = Date.now() - _fs_speed.ms;
-              result.rx_sec = (result.rx - _fs_speed.bytes_read) / (result.ms / 1000);
-              result.wx_sec = (result.wx - _fs_speed.bytes_write) / (result.ms / 1000);
-              result.tx_sec = result.rx_sec + result.wx_sec;
-            } else {
-              result.rx_sec = -1;
-              result.wx_sec = -1;
-              result.tx_sec = -1;
-            }
-            _fs_speed.bytes_read = result.rx;
-            _fs_speed.bytes_write = result.wx;
-            _fs_speed.bytes_overall = result.rx + result.wx;
-            _fs_speed.ms = Date.now();
-          }
-          if (callback) { callback(result) }
-          resolve(result);
-        })
       }
     });
   });
@@ -242,6 +271,46 @@ function fsStats(callback) {
 
 exports.fsStats = fsStats;
 
+function calcDiskIO(rIO, wIO) {
+  let result = {
+    rIO: 0,
+    wIO: 0,
+    tIO: 0,
+    rIO_sec: -1,
+    wIO_sec: -1,
+    tIO_sec: -1,
+    ms: 0
+  };
+  if (_disk_io && _disk_io.ms) {
+    result.rIO = rIO;
+    result.wIO = wIO;
+    result.tIO = rIO + wIO;
+    result.ms = Date.now() - _disk_io.ms;
+    result.rIO_sec = (result.rIO - _disk_io.rIO) / (result.ms / 1000);
+    result.wIO_sec = (result.wIO - _disk_io.wIO) / (result.ms / 1000);
+    result.tIO_sec = result.rIO_sec + result.wIO_sec;
+    _disk_io.rIO = rIO;
+    _disk_io.wIO = wIO;
+    _disk_io.rIO_sec = result.rIO_sec;
+    _disk_io.wIO_sec = result.wIO_sec;
+    _disk_io.tIO_sec = result.tIO_sec;
+    _disk_io.last_ms = result.ms;
+    _disk_io.ms = Date.now();
+  } else {
+    result.rIO = rIO;
+    result.wIO = wIO;
+    result.tIO = rIO + wIO;
+    _disk_io.rIO = rIO;
+    _disk_io.wIO = wIO;
+    _disk_io.rIO_sec = -1;
+    _disk_io.wIO_sec = -1;
+    _disk_io.tIO_sec = -1;
+    _disk_io.last_ms = 0;
+    _disk_io.ms = Date.now();
+  }
+  return result;
+}
+
 function disksIO(callback) {
 
   return new Promise((resolve, reject) => {
@@ -252,7 +321,7 @@ function disksIO(callback) {
         reject(error);
       }
 
-      var result = {
+      let result = {
         rIO: 0,
         wIO: 0,
         tIO: 0,
@@ -261,81 +330,67 @@ function disksIO(callback) {
         tIO_sec: -1,
         ms: 0
       };
-      if (_linux) {
+      let rIO = 0;
-        // prints Block layer statistics for all mounted volumes
+      let wIO = 0;
-        // var cmd = "for mount in `lsblk | grep / | sed -r 's/│ └─//' | cut -d ' ' -f 1`; do cat /sys/block/$mount/stat | sed -r 's/ +/;/g' | sed -r 's/^;//'; done";
-        // var cmd = "for mount in `lsblk | grep / | sed 's/[│└─├]//g' | awk '{$1=$1};1' | cut -d ' ' -f 1 | sort -u`; do cat /sys/block/$mount/stat | sed -r 's/ +/;/g' | sed -r 's/^;//'; done";
-        let cmd = "for mount in `lsblk | grep ' disk ' | sed 's/[│└─├]//g' | awk '{$1=$1};1' | cut -d ' ' -f 1 | sort -u`; do cat /sys/block/$mount/stat | sed -r 's/ +/;/g' | sed -r 's/^;//'; done";
 
-        exec(cmd, function (error, stdout) {
+      if ((_disk_io && !_disk_io.ms) || (_disk_io && _disk_io.ms && Date.now() - _disk_io.ms >= 500)) {
-          if (!error) {
+        if (_linux) {
-            let lines = stdout.split('\n');
+          // prints Block layer statistics for all mounted volumes
-            lines.forEach(function (line) {
+          // var cmd = "for mount in `lsblk | grep / | sed -r 's/│ └─//' | cut -d ' ' -f 1`; do cat /sys/block/$mount/stat | sed -r 's/ +/;/g' | sed -r 's/^;//'; done";
-              // ignore empty lines
+          // var cmd = "for mount in `lsblk | grep / | sed 's/[│└─├]//g' | awk '{$1=$1};1' | cut -d ' ' -f 1 | sort -u`; do cat /sys/block/$mount/stat | sed -r 's/ +/;/g' | sed -r 's/^;//'; done";
-              if (!line) return;
+          let cmd = "for mount in `lsblk | grep ' disk ' | sed 's/[│└─├]//g' | awk '{$1=$1};1' | cut -d ' ' -f 1 | sort -u`; do cat /sys/block/$mount/stat | sed -r 's/ +/;/g' | sed -r 's/^;//'; done";
 
-              // sum r/wIO of all disks to compute all disks IO
+          exec(cmd, function (error, stdout) {
-              let stats = line.split(';');
+            if (!error) {
-              result.rIO += parseInt(stats[0]);
+              let lines = stdout.split('\n');
-              result.wIO += parseInt(stats[4]);
+              lines.forEach(function (line) {
-            });
+                // ignore empty lines
-            result.tIO = result.rIO + result.wIO;
+                if (!line) return;
-            if (_disk_io && _disk_io.ms) {
+
-              result.ms = Date.now() - _disk_io.ms;
+                // sum r/wIO of all disks to compute all disks IO
-              result.rIO_sec = (result.rIO - _disk_io.rIO) / (result.ms / 1000);
+                let stats = line.split(';');
-              result.wIO_sec = (result.wIO - _disk_io.wIO) / (result.ms / 1000);
+                rIO += parseInt(stats[0]);
-              result.tIO_sec = result.rIO_sec + result.wIO_sec;
+                wIO += parseInt(stats[4]);
+              });
+              result = calcDiskIO(rIO, wIO);
+
+              if (callback) { callback(result) }
+              resolve(result);
             } else {
-              result.rIO_sec = -1;
+              if (callback) { callback(result) }
-              result.wIO_sec = -1;
+              resolve(result);
-              result.tIO_sec = -1;
             }
-            _disk_io.rIO = result.rIO;
+          });
-            _disk_io.wIO = result.wIO;
+        }
-            _disk_io.tIO = result.tIO;
+        if (_darwin) {
-            _disk_io.ms = Date.now();
+          exec("ioreg -c IOBlockStorageDriver -k Statistics -r -w0 | sed -n '/IOBlockStorageDriver/,/Statistics/p' | grep 'Statistics' | tr -cd '01234567890,\n' | awk -F',' '{print $1, $11}'", function (error, stdout) {
+            if (!error) {
+              let lines = stdout.toString().split('\n');
+              lines.forEach(function (line) {
+                line = line.trim();
+                if (line != '') {
+                  line = line.split(' ');
 
+                  rIO += parseInt(line[1]);
+                  wIO += parseInt(line[0]);
+                }
+              });
+              result = calcDiskIO(rIO, wIO);
+            }
             if (callback) { callback(result) }
             resolve(result);
-          } else {
+          })
-            if (callback) { callback(result) }
+        }
-            resolve(result);
+      } else {
-          }
+        result.rIO = _disk_io.rIO;
-        });
+        result.wIO = _disk_io.wIO;
-      }
+        result.tIO = _disk_io.rIO + _disk_io.wIO;
-      if (_darwin) {
+        result.ms = _disk_io.last_ms;
-        exec("ioreg -c IOBlockStorageDriver -k Statistics -r -w0 | sed -n '/IOBlockStorageDriver/,/Statistics/p' | grep 'Statistics' | tr -cd '01234567890,\n' | awk -F',' '{print $1, $11}'", function (error, stdout) {
+        result.rIO_sec = _disk_io.rIO_sec;
-          if (!error) {
+        result.wIO_sec = _disk_io.wIO_sec;
-            let lines = stdout.toString().split('\n');
+        result.tIO_sec = _disk_io.tIO_sec;
-            lines.forEach(function (line) {
+        if (callback) { callback(result) }
-              line = line.trim();
+        resolve(result);
-              if (line != '') {
-                line = line.split(' ');
-
-                result.rIO += parseInt(line[1]);
-                result.wIO += parseInt(line[0]);
-              }
-            });
-
-            result.tIO = result.rIO + result.wIO;
-            if (_disk_io && _disk_io.ms) {
-              result.ms = Date.now() - _disk_io.ms;
-              result.rIO_sec = (result.rIO - _disk_io.rIO) / (result.ms / 1000);
-              result.wIO_sec = (result.wIO - _disk_io.wIO) / (result.ms / 1000);
-              result.tIO_sec = result.rIO_sec + result.wIO_sec;
-            } else {
-              result.rIO_sec = -1;
-              result.wIO_sec = -1;
-              result.tIO_sec = -1;
-            }
-            _disk_io.rIO = result.rIO;
-            _disk_io.wIO = result.wIO;
-            _disk_io.tIO = result.tIO;
-            _disk_io.ms = Date.now();
-          }
-          if (callback) { callback(result) }
-          resolve(result);
-        })
       }
     });
   });

lib/index.js

@@ -81,6 +81,7 @@
 // --------------------------------
 //
 // version	date	comment
+// 3.10.1	2016-11-14	optimization fsStats, disksIO, networkStats
 // 3.10.0	2016-11-12	added blockDevices, fixed fsSize,  added file system type
 // 3.9.0	2016-11-11	added MAC address to networkInterfaces, fixed currentLoad
 // 3.8.1	2016-11-04	updated docs

lib/network.js

@@ -108,7 +108,7 @@ function networkInterfaces(callback) {
             mac = details.mac
           });
           let internal = (ifaces[dev] && ifaces[dev][0]) ? ifaces[dev][0].internal : null;
-          result.push({ iface: dev, ip4: ip4, ip6: ip6, mac : mac, internal: internal })
+          result.push({ iface: dev, ip4: ip4, ip6: ip6, mac: mac, internal: internal })
         }
       }
       if (callback) { callback(result) }
@@ -122,26 +122,43 @@ exports.networkInterfaces = networkInterfaces;
 // --------------------------
 // NET - Speed
 
-function calcNetworkSpeed(iface, rx, tx) {
+function calcNetworkSpeed(iface, rx, tx, operstate) {
-  let rx_sec = -1;
+  let result = {
-  let tx_sec = -1;
+    iface: iface,
-  let ms = 0;
+    operstate: operstate,
+    rx: 0,
+    tx: 0,
+    rx_sec: -1,
+    tx_sec: -1,
+    ms: 0
+  };
+
   if (_network[iface] && _network[iface].ms) {
-    ms = Date.now() - _network[iface].ms;
+    result.rx = rx;
-    rx_sec = (rx - _network[iface].rx) / (ms / 1000);
+    result.tx = tx;
-    tx_sec = (tx - _network[iface].tx) / (ms / 1000);
+    result.ms = Date.now() - _network[iface].ms;
+    result.rx_sec = (rx - _network[iface].rx) / (result.ms / 1000);
+    result.tx_sec = (tx - _network[iface].tx) / (result.ms / 1000);
+    _network[iface].rx = rx;
+    _network[iface].tx = tx;
+    _network[iface].rx_sec = result.rx_sec;
+    _network[iface].tx_sec = result.tx_sec;
+    _network[iface].ms = Date.now();
+    _network[iface].last_ms = result.ms;
   } else {
-    _network[iface] = {};
+    result.rx = rx;
+    result.tx = tx;
+    if (!_network[iface]) _network[iface] = {};
+    _network[iface].rx = rx;
+    _network[iface].tx = tx;
+    _network[iface].rx_sec = -1;
+    _network[iface].tx_sec = -1;
+    _network[iface].ms = Date.now();
+    _network[iface].last_ms = 0;
   }
-  _network[iface].rx = rx;
+  return result;
-  _network[iface].tx = tx;
-  _network[iface].ms = Date.now();
-  return ({
-    rx_sec: rx_sec,
-    tx_sec: tx_sec,
-    ms: ms
-  })
 }
+
 function networkStats(iface, callback) {
 
   // fallback - if only callback is given
@@ -171,63 +188,70 @@ function networkStats(iface, callback) {
         ms: 0
       };
 
-      let cmd, lines, stats, speed;
+      let operstate = 'unknown';
+      let rx = 0;
+      let tx = 0;
 
-      if (_linux) {
+      let cmd, lines, stats;
-        if (fs.existsSync('/sys/class/net/' + iface)) {
+      if (!_network[iface] || (_network[iface] && !_network[iface].ms) || (_network[iface] && _network[iface].ms && Date.now() - _network[iface].ms >= 500)) {
-          cmd =
+        if (_linux) {
-            "cat /sys/class/net/" + iface + "/operstate; " +
+          if (fs.existsSync('/sys/class/net/' + iface)) {
-            "cat /sys/class/net/" + iface + "/statistics/rx_bytes; " +
+            cmd =
-            "cat /sys/class/net/" + iface + "/statistics/tx_bytes; ";
+              "cat /sys/class/net/" + iface + "/operstate; " +
-          exec(cmd, function (error, stdout) {
+              "cat /sys/class/net/" + iface + "/statistics/rx_bytes; " +
-            if (!error) {
+              "cat /sys/class/net/" + iface + "/statistics/tx_bytes; ";
-              lines = stdout.toString().split('\n');
+            exec(cmd, function (error, stdout) {
-              result.operstate = lines[0].trim();
+              if (!error) {
-              result.rx = parseInt(lines[1]);
+                lines = stdout.toString().split('\n');
-              result.tx = parseInt(lines[2]);
+                operstate = lines[0].trim();
+                rx = parseInt(lines[1]);
+                tx = parseInt(lines[2]);
 
-              speed = calcNetworkSpeed(iface, result.rx, result.tx);
+                result = calcNetworkSpeed(iface, rx, tx, operstate);
 
-              result.rx_sec = speed.rx_sec;
-              result.tx_sec = speed.tx_sec;
-              result.ms = speed.ms;
-            }
-            if (callback) { callback(result) }
-            resolve(result);
-          });
-        } else {
-          if (callback) { callback(result) }
-          resolve(result);
-        }
-      }
-      if (_darwin) {
-        cmd = "ifconfig " + iface + " | grep 'status'";
-        exec(cmd, function (error, stdout) {
-          result.operstate = (stdout.toString().split(':')[1] || '').trim();
-          result.operstate = (result.operstate || '').toLowerCase();
-          result.operstate = (result.operstate == 'active' ? 'up' : (result.operstate == 'inactive' ? 'down' : 'unknown'));
-          cmd = "netstat -bI " + iface;
-          exec(cmd, function (error, stdout) {
-            if (!error) {
-              lines = stdout.toString().split('\n');
-              // if there is less than 2 lines, no information for this interface was found
-              if (lines.length > 1 && lines[1].trim() != '') {
-                // skip header line
-                // use the second line because it is tied to the NIC instead of the ipv4 or ipv6 address
-                stats = lines[1].replace(/ +/g, " ").split(' ');
-                result.rx = parseInt(stats[6]);
-                result.tx = parseInt(stats[9]);
-
-                speed = calcNetworkSpeed(iface, result.rx, result.tx);
-
-                result.rx_sec = speed.rx_sec;
-                result.tx_sec = speed.tx_sec;
               }
-            }
+              if (callback) { callback(result) }
+              resolve(result);
+            });
+          } else {
             if (callback) { callback(result) }
             resolve(result);
+          }
+        }
+        if (_darwin) {
+          cmd = "ifconfig " + iface + " | grep 'status'";
+          exec(cmd, function (error, stdout) {
+            result.operstate = (stdout.toString().split(':')[1] || '').trim();
+            result.operstate = (result.operstate || '').toLowerCase();
+            result.operstate = (result.operstate == 'active' ? 'up' : (result.operstate == 'inactive' ? 'down' : 'unknown'));
+            cmd = "netstat -bI " + iface;
+            exec(cmd, function (error, stdout) {
+              if (!error) {
+                lines = stdout.toString().split('\n');
+                // if there is less than 2 lines, no information for this interface was found
+                if (lines.length > 1 && lines[1].trim() != '') {
+                  // skip header line
+                  // use the second line because it is tied to the NIC instead of the ipv4 or ipv6 address
+                  stats = lines[1].replace(/ +/g, " ").split(' ');
+                  rx = parseInt(stats[6]);
+                  tx = parseInt(stats[9]);
+
+                  result = calcNetworkSpeed(iface, rx, tx, operstate);
+                }
+              }
+              if (callback) { callback(result) }
+              resolve(result);
+            });
           });
-        });
+        }
+      } else {
+        result.rx = _network[iface].rx;
+        result.tx = _network[iface].tx;
+        result.rx_sec = _network[iface].rx_sec;
+        result.tx_sec = _network[iface].tx_sec;
+        result.ms = _network[iface].last_ms;
+        if (callback) { callback(result) }
+        resolve(result);
       }
     });
   });

lib/processes.js

@@ -84,7 +84,7 @@ function getLoad() {
       }
       if (_linux) {
         let now = Date.now() - _current_cpu.ms;
-        if (now >= 1000) {
+        if (now >= 500) {
           _current_cpu.ms = Date.now();
           exec("cat /proc/stat | grep 'cpu '", function (error, stdout) {
             if (!error) {