trunk/lttv/QUICKSTART.html

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   4   <title>Linux Trace Toolkit Quickstart</title>
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   7
   8 <h1>Linux Trace Toolkit Quickstart</h1>
   9
  10 Author : Mathieu Desnoyers, September 2005<br>
  11 Last update : January 21st, 2009<br>
  12
  13 <h2>Table of Contents</h2>
  14 <ul>
  15
  16 <li><a href="#intro" name="TOCintro">Introduction</a></li>
  17 <li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
  18 sources</a></li>
  19 <li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
  20 <li><a href="#section3" name="TOCsection3">Adding kernel and user-space
  21 tracepoints</a></li>
  22 <li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
  23 from LTTV</a>
  24
  25 </ul>
  26
  27 <hr />
  28
  29 <h2><a href="#TOCintro" name="intro">Introduction</a></h2>
  30 <p>
  31 This document is made of four parts : the first one explains how
  32 to install LTTng and LTTV from sources, the second one describes the steps
  33 to follow to trace a system and view it. The third part explains
  34 briefly how to add a new trace point to the kernel and to user space
  35 applications. The fourth and last part explains how to create Debian or RPM
  36 packages from the LTTng and LTTV sources.
  37 <p>
  38 These operations are made for installing the LTTng 0.86 tracer on a linux 2.6.X
  39 kernel. You will also find instructions for installation of LTTV 0.12.x : the
  40 Linux Trace Toolkit Viewer.
  41 To see the list of compatibilities between LTTng, ltt-control, LTTV, please
  42 refer to :
  43 <a
  44 href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>
  45 The lttng patch is necessary to have the tracing hooks in the kernel.
  46
  47 <br>
  48 <br>
  49 Supported architectures :
  50 <br>
  51 LTTng :<br>
  52 <li> x86 32/64 bits
  53 <li> PowerPC 32 and 64 bits
  54 <li> ARM (with limited timestamping precision, e.g. 1HZ. Need
  55 architecture-specific support for better precision)
  56 <li> MIPS
  57 <br>
  58 <br>
  59 LTTV :<br>
  60 <li> Intel 32/64 bits
  61 <li> PowerPC 32 and 64 bits
  62 <li> Possibly others. Takes care of endianness and type size difference between
  63 the LTTng traces and the LTTV analysis tool.
  64
  65 <hr />
  66
  67
  68 <h2><a href="#TOCsection2" name="section2">Installation from sources</a></h2>
  69 <p>
  70
  71 <li>Prerequisites</li>
  72 <ul>
  73 <p>
  74 Tools needed to follow the package download steps :
  75
  76 <li>wget
  77 <li>bzip2
  78 <li>gzip
  79 <li>tar
  80
  81 <p>
  82 You have to install the standard development libraries and programs necessary
  83 to compile a kernel :
  84
  85 <PRE>
  86 (from Documentation/Changes in the Linux kernel tree)
  87 Gnu C                2.95.3                # gcc --version
  88 Gnu make             3.79.1                # make --version
  89 binutils             2.12                  # ld -v
  90 util-linux           2.10o                 # fdformat --version
  91 module-init-tools    0.9.10                # depmod -V
  92 </PRE>
  93
  94 <p>
  95 You might also want to have libncurses5 to have the text mode kernel
  96 configuration menu, but there are alternatives.
  97
  98 <p>
  99 Prerequisites for LTTV 0.x.x installation are :
 100
 101 <PRE>
 102 gcc 3.2 or better
 103 gtk 2.4 or better development libraries
 104   (Debian : libgtk2.0, libgtk2.0-dev)
 105   (Fedora : gtk2, gtk2-devel)
 106   note : For Fedora users : this might require at least core 3 from Fedora,
 107   or you might have to compile your own GTK2 library.
 108 glib 2.4 or better development libraries
 109   (Debian : libglib2.0-0, libglib2.0-dev)
 110   (Fedora : glib2, glib2-devel)
 111 libpopt development libraries
 112   (Debian : libpopt0, libpopt-dev)
 113   (Fedora : popt)
 114 libpango development libraries
 115   (Debian : libpango1.0, libpango1.0-dev)
 116   (Fedora : pango, pango-devel)
 117 libc6 development librairies
 118   (Debian : libc6, libc6-dev)
 119   (Fedora : glibc, glibc)
 120 </PRE>
 121 </ul>
 122
 123 <li>Reminder</li>
 124
 125 <p>
 126 See the list of compatibilities between LTTng, ltt-control and LTTV at :
 127 <a
 128 href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
 129 versions compatibility</a>.
 130
 131
 132 <li>Getting the LTTng packages</li>
 133
 134 <PRE>
 135 su -
 136 mkdir /usr/src/lttng
 137 cd /usr/src/lttng
 138 (see http://ltt.polymtl.ca/lttng for package listing)
 139 wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
 140 bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 | tar xvof -
 141 </PRE>
 142
 143
 144 <li>Getting LTTng kernel sources</li>
 145
 146 <PRE>
 147 su -
 148 cd /usr/src
 149 wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
 150 bzip2 -cd linux-2.6.X.tar.bz2 | tar xvof -
 151 cd linux-2.6.X
 152 - For LTTng 0.9.4- cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1
 153 - For LTTng 0.9.5+ apply the patches in the order specified in the series file,
 154   or use quilt
 155 cd ..
 156 mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
 157 </PRE>
 158
 159
 160 <li>Installing a LTTng kernel</li>
 161
 162 <PRE>
 163 su -
 164 cd /usr/src/linux-2.6.X-lttng-0.x.xx
 165 make menuconfig (or make xconfig or make config)
 166     Select the < Help > button if you are not familiar with kernel
 167     configuration.
 168     Items preceded by [*] means they has to be built into the kernel.
 169     Items preceded by [M] means they has to be built as modules.
 170     Items preceded by [ ] means they should be removed.
 171   go to the "General setup" section
 172     Select the following options :
 173     [*] Prompt for development and/or incomplete code/drivers
 174     [*] Activate markers
 175     [*] Activate userspace markers ABI (experimental, optional)
 176     [*] Immediate value optimization (optional)
 177     [*] Linux Trace Toolkit Next Generation (LTTng) --->
 178     <M> or <*> Compile lttng tracing probes
 179     <M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
 180     <M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
 181     <M> or <*> Linux Trace Toolkit Serializer
 182     <M> or <*>   Linux Trace Toolkit Marker Control
 183     <M> or <*>     Linux Trace Toolkit Tracer
 184     [*] Align Linux Trace Toolkit Traces
 185     <M> or <*> Support logging events from userspace
 186     [*] Support trace extraction from crash dump
 187     <M> or <*> Linux Trace Toolkit Trace Controller
 188     <M> or <*> Linux Trace Toolkit State Dump
 189   Select <Exit>
 190   Select <Exit>
 191   Select <Yes>
 192 make
 193 make modules_install
 194 (if necessary, create a initrd with mkinitrd or your preferate alternative)
 195 (mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
 196
 197 -- on X86, X86_64
 198 make install
 199 reboot
 200 Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
 201
 202 -- on PowerPC
 203 cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
 204 cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
 205 cp .config /boot/config-2.6.X-lttng-0.x.xx
 206 depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 207 mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 208 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
 209 that comes first is the default kernel)
 210 ybin
 211 select the right entry at the yaboot prompt (see choices : tab, select : type
 212 the kernel name followed by enter)
 213 Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
 214 --
 215 </PRE>
 216
 217 <li>Editing the system wide configuration</li>
 218
 219 <p>
 220 You must activate debugfs and specify a mount point. This is typically done in
 221 fstab such that it happens at boot time.  If you have never used DebugFS before,
 222 these operation would do this for you :
 223
 224 <PRE>
 225 mkdir /mnt/debugfs
 226 cp /etc/fstab /etc/fstab.lttng.bkp
 227 echo "debugfs         /mnt/debugfs    debugfs rw              0       0"  >> /etc/fstab
 228 </PRE>
 229
 230 <p>
 231 then, rebooting or issuing the following command will activate debugfs :
 232 <PRE>
 233 mount /mnt/debugfs
 234 </PRE>
 235
 236 <p>
 237 You need to load the LTT modules to be able to control tracing from user
 238 space. This is done by issuing the following commands. Note however
 239 these commands load all LTT modules. Depending on what options you chose to
 240 compile statically, you may not need to issue all these commands.
 241
 242 <PRE>
 243 modprobe ltt-trace-control
 244 modprobe ltt-marker-control
 245 modprobe ltt-tracer
 246 modprobe ltt-serialize
 247 modprobe ltt-relay
 248 modprobe ipc-trace
 249 modprobe kernel-trace
 250 modprobe mm-trace
 251 modprobe net-trace
 252 modprobe fs-trace
 253 modprobe jbd2-trace
 254 modprobe ext4-trace
 255 modprobe syscall-trace
 256 modprobe trap-trace
 257 #if locking tracing is wanted, uncomment the following
 258 #modprobe lockdep-trace
 259 </PRE>
 260
 261 <p>
 262 If you want to have complete information about the kernel state (including all
 263 the process names), you need to load the ltt-statedump module. This is done by
 264 issuing the command :
 265
 266 <PRE>
 267 modprobe ltt-statedump
 268 </PRE>
 269 <p>
 270 You can automate at boot time loading the ltt-control module by :
 271
 272 <PRE>
 273 cp /etc/modules /etc/modules.bkp
 274 echo ltt-trace-control >> /etc/modules
 275 echo ltt-marker-control >> /etc/modules
 276 echo ltt-tracer >> /etc/modules
 277 echo ltt-serialize >> /etc/modules
 278 echo ltt-relay >> /etc/modules
 279 echo ipc-trace >> /etc/modules
 280 echo kernel-trace >> /etc/modules
 281 echo mm-trace >> /etc/modules
 282 echo net-trace >> /etc/modules
 283 echo fs-trace >> /etc/modules
 284 echo jbd2-trace >> /etc/modules
 285 echo ext4-trace >> /etc/modules
 286 echo syscall-trace >> /etc/modules
 287 echo trap-trace >> /etc/modules
 288 #if locking tracing is wanted, uncomment the following
 289 #echo lockdep-trace >> /etc/modules
 290 </PRE>
 291
 292 <li>Getting and installing the ltt-control package (on the traced machine)</li>
 293 <p>
 294 (note : the ltt-control package contains lttd and lttctl. Although it has the
 295 same name as the ltt-control kernel module, they are *not* the same thing.)
 296
 297 <PRE>
 298 su -
 299 cd /usr/src
 300 wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
 301 gzip -cd ltt-control-0.x-xxxx2008.tar.gz | tar xvof -
 302 cd ltt-control-0.x-xxxx2006
 303 (refer to README to see the development libraries that must be installed on you
 304 system)
 305 ./configure
 306 make
 307 make install
 308 </PRE>
 309
 310 <li>Userspace tracing</li>
 311
 312 <PRE>
 313 Make sure you selected the kernel menuconfig option :
 314     <M> or <*> Support logging events from userspace
 315 And that the ltt-userspace-event kernel module is loaded if selected as a
 316 module.
 317
 318 Simple userspace tracing is available through
 319 echo "some text to record" > /mnt/debugfs/ltt/write_event
 320
 321 It will appear in the trace under event :
 322 channel : userspace
 323 event name : event
 324 </PRE>
 325
 326 <li>Getting and installing the LTTV package (on the visualisation machine, same
 327 or different from the visualisation machine)</li>
 328
 329 <PRE>
 330 su -
 331 cd /usr/src
 332 wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
 333 gzip -cd lttv-0.x.xx-xxxx2008.tar.gz | tar xvof -
 334 cd lttv-0.x.xx-xxxx2008
 335 (refer to README to see the development libraries that must be installed on your
 336 system)
 337 ./configure
 338 make
 339 make install
 340
 341
 342 <li>Getting and installing the markers-userspace package for user space
 343 tracing (experimental)</li>
 344 <p>
 345 See <a
 346 href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.
 347
 348 <hr />
 349
 350
 351 <h2><a href="#TOCsection3" name="section3">Using LTTng and LTTV</a></h2>
 352
 353 <li>IMPORTANT : Arm Linux Kernel Markers after each boot</li>
 354 <PRE>
 355 ltt-armall
 356 </PRE>
 357
 358 <li>Use graphical LTTV to control tracing and analyse traces</li>
 359 <PRE>
 360 lttv-gui (or /usr/local/bin/lttv-gui)
 361   - Spot the "Tracing Control" icon : click on it
 362       (it's a traffic light icon)
 363     - enter the root password
 364     - click "start"
 365     - click "stop"
 366     - Yes
 367       * You should now see a trace
 368 </PRE>
 369
 370 <li>Use text mode LTTng to control tracing</li>
 371 <PRE>
 372 The tracing can be controlled from a terminal by using the lttctl command (as
 373 root).
 374
 375 Start tracing :
 376
 377 lttctl -C -w /tmp/trace1 trace1
 378
 379 Stop tracing and destroy trace channels :
 380
 381 lttctl -D trace1
 382
 383 see lttctl --help for details.
 384 <PRE>
 385 <p>
 386 (note : to see if the buffers has been filled, look at the dmesg output after
 387 lttctl -R or after stopping tracing from the GUI, it will show an event lost
 388 count. If it is the case, try using larger buffers. See lttctl --help to learn
 389 how. lttv now also shows event lost messages in the console when loading a trace
 390 with missing events or lost subbuffers.)
 391
 392 <li>Use text mode LTTV</li>
 393 <p>
 394 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
 395 graphical plugins available.
 396 <p>
 397 For example, a simple trace dump in text format is available with :
 398 <PRE>
 399 lttv -m textDump -t /tmp/trace
 400 </PRE>
 401 <p>
 402 See lttv -m textDump --help for detailed command line options of textDump.
 403 <p>
 404 It is, in the current state of the project, very useful to use "grep" on the
 405 text output to filter by specific event fields. You can later copy the timestamp
 406 of the events to the clipboard and paste them in the GUI by clicking on the
 407 bottom right label "Current time". Support for this type of filtering should
 408 be added to the filter module soon.
 409
 410 <li>Hybrid mode</li>
 411 <p>
 412 Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
 413 hybrid. It can be especially useful when studying big workloads on a long period
 414 of time.
 415 <p>
 416 When using this mode, the most important, low rate control information will be
 417 recorded during all the trace by lttd (i.e. process creation/exit). The high
 418 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
 419 flight recorder buffer (now named flight-channelname_X).
 420 <p>
 421 The following lttctl commands take an hybrid trace :
 422 <p>
 423 Create trace channel, start lttd on normal channels, start tracing:
 424 <PRE>
 425 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
 426 </PRE>
 427 <p>
 428 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
 429 <PRE>
 430 lttctl -D -w /tmp/trace2 trace2
 431 </PRE>
 432 <p>
 433 Each "overwrite" channel is flight recorder channel.
 434
 435 <li>Flight recorder mode</li>
 436 <p>
 437 The flight recorder mode writes data into overwritten buffers for all channels,
 438 including control channels, except for the facilities tracefiles. It consists of
 439 setting all channels to "overwrite".
 440 <p>
 441 The following lttctl commands take a flight recorder trace :
 442 <PRE>
 443 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
 444 ...
 445 lttctl -D -w /tmp/trace3 trace3
 446 </PRE>
 447
 448 **************************************************************
 449 ** Section 4 * Adding new instrumentations with the markers **
 450 **************************************************************
 451
 452 See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
 453 tree.
 454
 455 * Add new events to userspace programs with userspace markers
 456 http://ltt.polymtl.ca/packages/
 457
 458 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
 459 allows inserting markers in executables and libraries, currently only on x86_32
 460 and x86_64.
 461
 462 ***********************************************************
 463 ** Section 5 * Creating Debian or RPM packages           **
 464 ***********************************************************
 465
 466 * Create custom LTTV Debian packages
 467
 468 Use : dpkg-buildpackage -rfakeroot
 469
 470 You should then have your LTTV .deb files created for your architecture.
 471
 472 * Create custom LTTng packages
 473
 474 For building LTTng Debian packages :
 475
 476 Get the build tree with patches applies as explained in section 2.
 477
 478 make menuconfig (or xconfig or config) (customize your configuration)
 479 make-kpkg kernel_image
 480
 481 You will then see your freshly created .deb in /usr/src. Install it with
 482 dpkg -i /usr/src/(image-name).deb
 483
 484 Then, follow the section "Editing the system wide configuration" in section 2.
 485
 486
 487
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