Ebpf extend sync (#10814)

Extend synchronization thread.

web/gui/dashboard_info.js

@@ -1035,7 +1035,19 @@ netdataDashboard.context = {
     },
 
     'mem.sync': {
-        info: 'System calls for <code>sync()</code> which flushes file system buffers to storage devices. These calls can cause performance perturbations, and it can be useful to know if they are happening and how frequently. Based on the eBPF <a href="https://github.com/iovisor/bcc/blob/master/tools/syncsnoop.py" target="_blank">syncsnoop</a> from BCC tools.'
+        info: 'System calls for <a href="https://man7.org/linux/man-pages/man2/sync.2.html" target="_blank">sync() and syncfs()</a> which flush the file system buffers to storage devices. Performance perturbations might be caused by these calls. The <code>sync()</code> calls are based on the eBPF <a href="https://github.com/iovisor/bcc/blob/master/tools/syncsnoop.py" target="_blank">syncsnoop</a> from BCC tools.'
+    },
+
+    'mem.file_sync': {
+        info: 'System calls for <a href="https://man7.org/linux/man-pages/man2/fsync.2.html" target="_blank">fsync() and fdatasync()</a> transfer all modified page caches for the files on disk devices. These calls block until the device reports that the transfer has been completed.'
+    },
+
+    'mem.memory_map': {
+        info: 'System calls for <a href="https://man7.org/linux/man-pages/man2/msync.2.html" target="_blank">msync()</a> which flushes changes made to the in-core copy of a file that was mapped.'
+    },
+
+    'mem.file_segment': {
+        info: 'System calls for <a href="https://man7.org/linux/man-pages/man2/sync_file_range.2.html" target="_blank">sync_file_range()</a> permits fine control when synchronizing the open file referred to by the file descriptor fd with disk. This system call is extremely dangerous and should not be used in portable programs.'
     },
 
     // ------------------------------------------------------------------------