trunk/lttv/QUICKSTART.html

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
   2 <html>
   3 <head>
   4   <title>Linux Trace Toolkit Next Generation User Documentation</title>
   5 </head>
   6   <body>
   7
   8 <h1>Linux Trace Toolkit Next Generation User Documentation</h1>
   9
  10 Author : Mathieu Desnoyers, September 2005<br>
  11 Last update : January 21st, 2009<br>
  12 (originally known as the LTTng QUICKSTART guide)
  13
  14 <h2>Table of Contents</h2>
  15 <ul>
  16
  17 <li><a href="#intro" name="TOCintro">Introduction</a></li>
  18 <li><a href="#section1" name="TOCsection1">Installing LTTng and LTTV from
  19 sources</a></li>
  20 <ul>
  21 <li><a href="#prerequisites" name="TOCprerequisites">Prerequisistes</li>
  22 <li><a href="#getlttng" name="TOCgetlttng">Getting the LTTng packages</li>
  23 <li><a href="#getlttngsrc" name="TOCgetlttngsrc">Getting the LTTng kernel sources</li>
  24 <li><a href="#installlttng" name="TOCinstalllttng">Installing a LTTng kernel</li>
  25 <li><a href="#editconfig" name="TOCeditconfig">Editing the system wide
  26 configuration</a>
  27 <li><a href="#getlttctl" name="TOCgetlttctl">Getting and installing the
  28 ltt-control package</li>
  29 <li><a href="#userspacetracing" name="TOCuserspacetracing">Userspace Tracing</li>
  30 <li><a href="#getlttv" name="TOCgetlttv">Getting and installing the LTTV package</ul>
  31 <li><a href="#section2" name="TOCsection2">Using LTTng and LTTV</a></li>
  32 <li><a href="#section3" name="TOCsection3">Adding kernel and user-space
  33 instrumentation</a>
  34 <ul>
  35 <li><a href="#kerneltp" name="TOCkerneltp">Adding kernel instrumentation</a></li>
  36 <li><a href="#usertp" name="TOCusertp">Adding userspace instrumentation</a></li>
  37 </ul>
  38
  39 <li><a href="#section4" name="TOCsection4">Creating Debian and RPM packages
  40 from LTTV</a>
  41
  42 </ul>
  43
  44 <hr />
  45
  46 <h2><a href="#TOCintro" name="intro">Introduction</a></h2>
  47 <p>
  48 This document is made of four parts : the first one explains how
  49 to install LTTng and LTTV from sources, the second one describes the steps
  50 to follow to trace a system and view it. The third part explains
  51 briefly how to add a new trace point to the kernel and to user space
  52 applications. The fourth and last part explains how to create Debian or RPM
  53 packages from the LTTng and LTTV sources.
  54 <p>
  55 These operations are made for installing the LTTng 0.86 tracer on a linux 2.6.X
  56 kernel. You will also find instructions for installation of LTTV 0.12.x : the
  57 Linux Trace Toolkit Viewer.
  58 To see the list of compatibilities between LTTng, ltt-control, LTTV, please
  59 refer to :
  60 <a
  61 href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV versions compatibility</a>
  62 The lttng patch is necessary to have the tracing hooks in the kernel.
  63
  64 <br>
  65 <br>
  66 Supported architectures :
  67 br>
  68 LTTng :<br>
  69 <li> x86 32/64 bits
  70 <li> PowerPC 32 and 64 bits
  71 <li> ARM (with limited timestamping precision, e.g. 1HZ. Need
  72 architecture-specific support for better precision)
  73 <li> MIPS
  74 <br>
  75 <br>
  76 LTTV :<br>
  77 <li> Intel 32/64 bits
  78 <li> PowerPC 32 and 64 bits
  79 <li> Possibly others. Takes care of endianness and type size difference between
  80 the LTTng traces and the LTTV analysis tool.
  81
  82 <hr />
  83
  84
  85 <h2><a href="#TOCsection1" name="section1">Installation from sources</a></h2>
  86 <p>
  87
  88 <h3><a href="#TOCprerequisites" name="prerequisites">Prerequisites</a></h3>
  89 <ul>
  90 <p>
  91 Tools needed to follow the package download steps :
  92
  93 <li>wget
  94 <li>bzip2
  95 <li>gzip
  96 <li>tar
  97
  98 <p>
  99 You have to install the standard development libraries and programs necessary
 100 to compile a kernel :
 101
 102 <PRE>
 103 (from Documentation/Changes in the Linux kernel tree)
 104 Gnu C                2.95.3                # gcc --version
 105 Gnu make             3.79.1                # make --version
 106 binutils             2.12                  # ld -v
 107 util-linux           2.10o                 # fdformat --version
 108 module-init-tools    0.9.10                # depmod -V
 109 </PRE>
 110
 111 <p>
 112 You might also want to have libncurses5 to have the text mode kernel
 113 configuration menu, but there are alternatives.
 114
 115 <p>
 116 Prerequisites for LTTV 0.x.x installation are :
 117
 118 <PRE>
 119 gcc 3.2 or better
 120 gtk 2.4 or better development libraries
 121   (Debian : libgtk2.0, libgtk2.0-dev)
 122   (Fedora : gtk2, gtk2-devel)
 123   note : For Fedora users : this might require at least core 3 from Fedora,
 124   or you might have to compile your own GTK2 library.
 125 glib 2.4 or better development libraries
 126   (Debian : libglib2.0-0, libglib2.0-dev)
 127   (Fedora : glib2, glib2-devel)
 128 libpopt development libraries
 129   (Debian : libpopt0, libpopt-dev)
 130   (Fedora : popt)
 131 libpango development libraries
 132   (Debian : libpango1.0, libpango1.0-dev)
 133   (Fedora : pango, pango-devel)
 134 libc6 development librairies
 135   (Debian : libc6, libc6-dev)
 136   (Fedora : glibc, glibc)
 137 </PRE>
 138 </ul>
 139
 140 <li>Reminder</li>
 141
 142 <p>
 143 See the list of compatibilities between LTTng, ltt-control and LTTV at :
 144 <a
 145 href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/lttng-lttv-compatibility.html">LTTng+LTTV
 146 versions compatibility</a>.
 147
 148
 149 <h3><a href="#TOCgetlttng" name="getlttng">Getting the LTTng packages</a></h3>
 150
 151 <PRE>
 152 su -
 153 mkdir /usr/src/lttng
 154 cd /usr/src/lttng
 155 (see http://ltt.polymtl.ca/lttng for package listing)
 156 wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
 157 bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 | tar xvof -
 158 </PRE>
 159
 160
 161 <h3><a href="#TOCgetlttngsrc" name="getlttngsrc">Getting LTTng kernel sources</a></h3>
 162
 163 <PRE>
 164 su -
 165 cd /usr/src
 166 wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
 167 bzip2 -cd linux-2.6.X.tar.bz2 | tar xvof -
 168 cd linux-2.6.X
 169 - For LTTng 0.9.4- cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1
 170 - For LTTng 0.9.5+ apply the patches in the order specified in the series file,
 171   or use quilt
 172 cd ..
 173 mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
 174 </PRE>
 175
 176
 177 <h3><a href="#TOCinstalllttng" name="installlttng">Installing a LTTng kernel</a></h3>
 178
 179 <PRE>
 180 su -
 181 cd /usr/src/linux-2.6.X-lttng-0.x.xx
 182 make menuconfig (or make xconfig or make config)
 183     Select the < Help > button if you are not familiar with kernel
 184     configuration.
 185     Items preceded by [*] means they has to be built into the kernel.
 186     Items preceded by [M] means they has to be built as modules.
 187     Items preceded by [ ] means they should be removed.
 188   go to the "General setup" section
 189     Select the following options :
 190     [*] Prompt for development and/or incomplete code/drivers
 191     [*] Activate markers
 192     [*] Activate userspace markers ABI (experimental, optional)
 193     [*] Immediate value optimization (optional)
 194     [*] Linux Trace Toolkit Next Generation (LTTng) --->
 195     <M> or <*> Compile lttng tracing probes
 196     <M> or <*> Linux Trace Toolkit High-speed Lockless Data Relay
 197     <M> or <*> Linux Trace Toolkit Lock-Protected Data Relay
 198     <M> or <*> Linux Trace Toolkit Serializer
 199     <M> or <*>   Linux Trace Toolkit Marker Control
 200     <M> or <*>     Linux Trace Toolkit Tracer
 201     [*] Align Linux Trace Toolkit Traces
 202     <M> or <*> Support logging events from userspace
 203     [*] Support trace extraction from crash dump
 204     <M> or <*> Linux Trace Toolkit Trace Controller
 205     <M> or <*> Linux Trace Toolkit State Dump
 206   Select <Exit>
 207   Select <Exit>
 208   Select <Yes>
 209 make
 210 make modules_install
 211 (if necessary, create a initrd with mkinitrd or your preferate alternative)
 212 (mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
 213
 214 -- on X86, X86_64
 215 make install
 216 reboot
 217 Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
 218
 219 -- on PowerPC
 220 cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
 221 cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
 222 cp .config /boot/config-2.6.X-lttng-0.x.xx
 223 depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 224 mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 225 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
 226 that comes first is the default kernel)
 227 ybin
 228 select the right entry at the yaboot prompt (see choices : tab, select : type
 229 the kernel name followed by enter)
 230 Select the Linux 2.6.X-lttng-0.x.xx kernel in your boot loader.
 231 --
 232 </PRE>
 233
 234 <h3><a href="#TOCeditconfig" name="editconfig">Editing the system wide
 235 configuration</a></h3>
 236
 237 <p>
 238 You must activate debugfs and specify a mount point. This is typically done in
 239 fstab such that it happens at boot time.  If you have never used DebugFS before,
 240 these operation would do this for you :
 241
 242 <PRE>
 243 mkdir /mnt/debugfs
 244 cp /etc/fstab /etc/fstab.lttng.bkp
 245 echo "debugfs         /mnt/debugfs    debugfs rw              0       0"  >> /etc/fstab
 246 </PRE>
 247
 248 <p>
 249 then, rebooting or issuing the following command will activate debugfs :
 250 <PRE>
 251 mount /mnt/debugfs
 252 </PRE>
 253
 254 <p>
 255 You need to load the LTT modules to be able to control tracing from user
 256 space. This is done by issuing the following commands. Note however
 257 these commands load all LTT modules. Depending on what options you chose to
 258 compile statically, you may not need to issue all these commands.
 259
 260 <PRE>
 261 modprobe ltt-trace-control
 262 modprobe ltt-marker-control
 263 modprobe ltt-tracer
 264 modprobe ltt-serialize
 265 modprobe ltt-relay
 266 modprobe ipc-trace
 267 modprobe kernel-trace
 268 modprobe mm-trace
 269 modprobe net-trace
 270 modprobe fs-trace
 271 modprobe jbd2-trace
 272 modprobe ext4-trace
 273 modprobe syscall-trace
 274 modprobe trap-trace
 275 #if locking tracing is wanted, uncomment the following
 276 #modprobe lockdep-trace
 277 </PRE>
 278
 279 <p>
 280 If you want to have complete information about the kernel state (including all
 281 the process names), you need to load the ltt-statedump module. This is done by
 282 issuing the command :
 283
 284 <PRE>
 285 modprobe ltt-statedump
 286 </PRE>
 287 <p>
 288 You can automate at boot time loading the ltt-control module by :
 289
 290 <PRE>
 291 cp /etc/modules /etc/modules.bkp
 292 echo ltt-trace-control >> /etc/modules
 293 echo ltt-marker-control >> /etc/modules
 294 echo ltt-tracer >> /etc/modules
 295 echo ltt-serialize >> /etc/modules
 296 echo ltt-relay >> /etc/modules
 297 echo ipc-trace >> /etc/modules
 298 echo kernel-trace >> /etc/modules
 299 echo mm-trace >> /etc/modules
 300 echo net-trace >> /etc/modules
 301 echo fs-trace >> /etc/modules
 302 echo jbd2-trace >> /etc/modules
 303 echo ext4-trace >> /etc/modules
 304 echo syscall-trace >> /etc/modules
 305 echo trap-trace >> /etc/modules
 306 #if locking tracing is wanted, uncomment the following
 307 #echo lockdep-trace >> /etc/modules
 308 </PRE>
 309
 310
 311 <h3><a href="#TOCgetlttctl" name="getlttctl">Getting and installing the
 312 ltt-control package (on the traced machine)</a></h3>
 313 <p>
 314 (note : the ltt-control package contains lttd and lttctl. Although it has the
 315 same name as the ltt-control kernel module, they are *not* the same thing.)
 316
 317 <PRE>
 318 su -
 319 cd /usr/src
 320 wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
 321 gzip -cd ltt-control-0.x-xxxx2008.tar.gz | tar xvof -
 322 cd ltt-control-0.x-xxxx2006
 323 (refer to README to see the development libraries that must be installed on you
 324 system)
 325 ./configure
 326 make
 327 make install
 328 </PRE>
 329
 330 <h3><a href="#TOCuserspacetracing" name="userspacetracing">Userspace tracing</a></h3>
 331
 332 <PRE>
 333 Make sure you selected the kernel menuconfig option :
 334     <M> or <*> Support logging events from userspace
 335 And that the ltt-userspace-event kernel module is loaded if selected as a
 336 module.
 337
 338 Simple userspace tracing is available through
 339 echo "some text to record" > /mnt/debugfs/ltt/write_event
 340
 341 It will appear in the trace under event :
 342 channel : userspace
 343 event name : event
 344 </PRE>
 345
 346 <h3><a href="#TOCgetlttv" name="getlttv">Getting and installing the LTTV package
 347 (on the visualisation machine, same
 348 or different from the visualisation machine)</a></h3>
 349
 350 <PRE>
 351 su -
 352 cd /usr/src
 353 wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
 354 gzip -cd lttv-0.x.xx-xxxx2008.tar.gz | tar xvof -
 355 cd lttv-0.x.xx-xxxx2008
 356 (refer to README to see the development libraries that must be installed on your
 357 system)
 358 ./configure
 359 make
 360 make install
 361 </PRE>
 362
 363 <hr />
 364
 365
 366 <h2><a href="#TOCsection2" name="section2">Using LTTng and LTTV</a></h2>
 367
 368 <li>IMPORTANT : Arm Linux Kernel Markers after each boot</li>
 369 <PRE>
 370 ltt-armall
 371 </PRE>
 372
 373 <li>Use graphical LTTV to control tracing and analyse traces</li>
 374 <PRE>
 375 lttv-gui (or /usr/local/bin/lttv-gui)
 376   - Spot the "Tracing Control" icon : click on it
 377       (it's a traffic light icon)
 378     - enter the root password
 379     - click "start"
 380     - click "stop"
 381     - Yes
 382       * You should now see a trace
 383 </PRE>
 384
 385 <li>Use text mode LTTng to control tracing</li>
 386 <PRE>
 387 The tracing can be controlled from a terminal by using the lttctl command (as
 388 root).
 389
 390 Start tracing :
 391
 392 lttctl -C -w /tmp/trace1 trace1
 393
 394 Stop tracing and destroy trace channels :
 395
 396 lttctl -D trace1
 397
 398 see lttctl --help for details.
 399 </PRE>
 400 <p>
 401 (note : to see if the buffers has been filled, look at the dmesg output after
 402 lttctl -R or after stopping tracing from the GUI, it will show an event lost
 403 count. If it is the case, try using larger buffers. See lttctl --help to learn
 404 how. lttv now also shows event lost messages in the console when loading a trace
 405 with missing events or lost subbuffers.)
 406
 407 <li>Use text mode LTTV</li>
 408 <p>
 409 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
 410 graphical plugins available.
 411 <p>
 412 For example, a simple trace dump in text format is available with :
 413 <PRE>
 414 lttv -m textDump -t /tmp/trace
 415 </PRE>
 416 <p>
 417 See lttv -m textDump --help for detailed command line options of textDump.
 418 <p>
 419 It is, in the current state of the project, very useful to use "grep" on the
 420 text output to filter by specific event fields. You can later copy the timestamp
 421 of the events to the clipboard and paste them in the GUI by clicking on the
 422 bottom right label "Current time". Support for this type of filtering should
 423 be added to the filter module soon.
 424
 425 <li>Hybrid mode</li>
 426 <p>
 427 Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
 428 hybrid. It can be especially useful when studying big workloads on a long period
 429 of time.
 430 <p>
 431 When using this mode, the most important, low rate control information will be
 432 recorded during all the trace by lttd (i.e. process creation/exit). The high
 433 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
 434 flight recorder buffer (now named flight-channelname_X).
 435 <p>
 436 The following lttctl commands take an hybrid trace :
 437 <p>
 438 Create trace channel, start lttd on normal channels, start tracing:
 439 <PRE>
 440 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
 441 </PRE>
 442 <p>
 443 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
 444 <PRE>
 445 lttctl -D -w /tmp/trace2 trace2
 446 </PRE>
 447 <p>
 448 Each "overwrite" channel is flight recorder channel.
 449
 450 <li>Flight recorder mode</li>
 451 <p>
 452 The flight recorder mode writes data into overwritten buffers for all channels,
 453 including control channels, except for the facilities tracefiles. It consists of
 454 setting all channels to "overwrite".
 455 <p>
 456 The following lttctl commands take a flight recorder trace :
 457 <PRE>
 458 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
 459 ...
 460 lttctl -D -w /tmp/trace3 trace3
 461 </PRE>
 462
 463 <hr />
 464
 465
 466 <h2><a href="#TOCsection3" name="section3">Adding new instrumentations with the
 467 markers</a></h2>
 468 <p>
 469
 470 <h3><a href="#TOCkerneltp" name="kerneltp">Adding kernel
 471 instrumentation</a></h3>
 472
 473 <p>
 474 See <a
 475 href="http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=blob;f=Documentation/markers.txt">Documentation/markers.txt</a>
 476 and <a
 477 href="http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=blob;f=Documentation/tracepoints.txt">Documentation/tracepoints.txt</a> in your kernel
 478 tree.
 479 <p>
 480 Also see <a
 481 href="http://git.kernel.org/?p=linux/kernel/git/compudj/linux-2.6-lttng.git;a=tree;f=ltt/probes">ltt/probes/</a>
 482 for LTTng probe examples.
 483
 484 <h3><a href="#TOCusertp" name="usertp">Adding userspace instrumentation</a></h3>
 485
 486 <li>Add new events to userspace programs with
 487 <a href="http://ltt.polymtl.ca/packages/">userspace markers packages</a></li>
 488
 489 <p>
 490 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
 491 allows inserting markers in executables and libraries, currently only on x86_32
 492 and x86_64.
 493 See <a
 494 href="http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2">markers-userspace-0.5.tar.bz2</a> or more recent.
 495
 496 <p>
 497 Note that a new design document for a 3rd generation of tracepoint/marker-based
 498 userspace tracing is available at <a
 499 href="http://ltt.polymtl.ca/svn/trunk/lttv/doc/developer/ust.html">LTTng User-space Tracing
 500 Design"</a>. This new infrastructure is not yet implemented.
 501
 502 <p>
 503 The easy quick-and-dirty way to perform userspace tracing is currently to write
 504 an string to /mnt/debugfs/ltt/write_event. See <a
 505 href="#userspacetracing">Userspace tracing</a> in the
 506 installation for sources section of this document.
 507
 508 <hr />
 509
 510 <h2><a href="#TOCsection4" name="section4">Creating Debian or RPM packages</a></h2>
 511 <p>
 512
 513 <li>Create custom LTTV Debian packages</li>
 514
 515 <PRE>
 516 Use : dpkg-buildpackage -rfakeroot
 517 </PRE>
 518 <p>
 519 You should then have your LTTV .deb files created for your architecture.
 520
 521 <li>Create custom LTTng packages</li>
 522 <p>
 523 For building LTTng Debian packages :
 524 get the build tree with patches applies as explained in section 2.
 525
 526 <PRE>
 527 make menuconfig (or xconfig or config) (customize your configuration)
 528 make-kpkg kernel_image
 529 </PRE>
 530 <p>
 531 You will then see your freshly created .deb in /usr/src. Install it with
 532 <PRE>
 533 dpkg -i /usr/src/(image-name).deb
 534 </PRE>
 535 <p>
 536 Then, follow the section "Editing the system wide configuration" in section 2.
 537
 538
 539
 540   </body>
 541 </html>