Add preferences help tooltips

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/init.c b/init.c
index f1446ca..fd61c68 100644
--- a/init.c
+++ b/init.c
@@ -1216,20 +1216,62 @@
 
 #ifdef FIO_INC_DEBUG
 struct debug_level debug_levels[] = {
-	{ .name = "process",	.shift = FD_PROCESS, },
-	{ .name = "file",	.shift = FD_FILE, },
-	{ .name = "io",		.shift = FD_IO, },
-	{ .name = "mem",	.shift = FD_MEM, },
-	{ .name = "blktrace",	.shift = FD_BLKTRACE },
-	{ .name = "verify",	.shift = FD_VERIFY },
-	{ .name = "random",	.shift = FD_RANDOM },
-	{ .name = "parse",	.shift = FD_PARSE },
-	{ .name = "diskutil",	.shift = FD_DISKUTIL },
-	{ .name = "job",	.shift = FD_JOB },
-	{ .name = "mutex",	.shift = FD_MUTEX },
-	{ .name	= "profile",	.shift = FD_PROFILE },
-	{ .name = "time",	.shift = FD_TIME },
-	{ .name = "net",	.shift = FD_NET },
+	{ .name = "process",
+	  .help = "Process creation/exit logging",
+	  .shift = FD_PROCESS,
+	},
+	{ .name = "file",
+	  .help = "File related action logging",
+	  .shift = FD_FILE,
+	},
+	{ .name = "io",
+	  .help = "IO and IO engine action logging (offsets, queue, completions, etc)",
+	  .shift = FD_IO,
+	},
+	{ .name = "mem",
+	  .help = "Memory allocation/freeing logging",
+	  .shift = FD_MEM,
+	},
+	{ .name = "blktrace",
+	  .help = "blktrace action logging",
+	  .shift = FD_BLKTRACE,
+	},
+	{ .name = "verify",
+	  .help = "IO verification action logging",
+	  .shift = FD_VERIFY,
+	},
+	{ .name = "random",
+	  .help = "Random generation logging",
+	  .shift = FD_RANDOM,
+	},
+	{ .name = "parse",
+	  .help = "Parser logging",
+	  .shift = FD_PARSE,
+	},
+	{ .name = "diskutil",
+	  .help = "Disk utility logging actions",
+	  .shift = FD_DISKUTIL,
+	},
+	{ .name = "job",
+	  .help = "Logging related to creating/destroying jobs",
+	  .shift = FD_JOB,
+	},
+	{ .name = "mutex",
+	  .help = "Mutex logging",
+	  .shift = FD_MUTEX
+	},
+	{ .name	= "profile",
+	  .help = "Logging related to profiles",
+	  .shift = FD_PROFILE,
+	},
+	{ .name = "time",
+	  .help = "Logging related to time keeping functions",
+	  .shift = FD_TIME,
+	},
+	{ .name = "net",
+	  .help = "Network logging",
+	  .shift = FD_NET,
+	},
 	{ .name = NULL, },
 };