trunk/lttv/QUICKSTART

   1 Linux Trace Toolkit Quickstart
   2 ------------------------------
   3 Author : Mathieu Desnoyers, September 2005
   4 Last update : July 31, 2008
   5
   6
   7 This document is made of four parts : the first one explains how to install
   8 LTTng and LTTV from Debian and RPM binary packages, the second one explains how
   9 to install LTTng and LTTV from sources and the third one describes the steps
  10 to follow to trace a system and view it. The fourth and last part explains
  11 briefly how to add a new trace point to the kernel and to user space
  12 applications.
  13
  14 What you will typically want is to read sections 2 and 3 : install LTTng from
  15 sources and use it.
  16
  17 These operations are made for installing the LTTng 0.67 tracer on a linux 2.6.X
  18 kernel. You will also find instructions for installation of LTTV 0.12.x : the
  19 Linux Trace Toolkit Viewer.
  20
  21 To see the list of compatibilities between LTTng, ltt-control, LTTV and
  22 markers-userspace, please refer to :
  23 http://ltt.polymtl.ca > LTTng+LTTV versions compatibility
  24
  25
  26
  27 The following lttng patch is necessary to have the tracing hooks in the kernel.
  28 The following ltt-control module controls the tracing.
  29
  30 Required programs and libraries are assumed to be automatically installed in an
  31 installation with Debian or RPM packages. In the case of an installation from
  32 sources, the dependencies are listed.
  33
  34
  35 ** Current development status **
  36
  37 LTTng :
  38 supported architectures :
  39 Intel Pentium (UP/SMP) with TSC
  40 PowerPC 32 and 64 bits
  41 ARM
  42 x86_64
  43 C2 Microsystems (variant of MIPS)
  44
  45 LTTV :
  46 supported architectures :
  47 Intel i386 and better
  48 Intel 64 bits
  49 PowerPC 32 and 64 bits
  50
  51
  52 ***********************************************************
  53 ** Section 1 * Installation from Debian or RPM packages  **
  54 ***********************************************************
  55
  56 * Create custom LTTV Debian packages
  57
  58 Use : dpkg-buildpackage -rfakeroot
  59
  60 You should then have your LTTV .deb files created for your architecture.
  61
  62 * Create custom LTTng packages
  63
  64 For building LTTng Debian packages :
  65
  66 Get the build tree with patches applies as explained in section 2.
  67
  68 make menuconfig (or xconfig or config) (customize your configuration)
  69 make-kpkg kernel_image
  70
  71 You will then see your freshly created .deb in /usr/src. Install it with
  72 dpkg -i /usr/src/(image-name).deb
  73
  74 Then, follow the section "Editing the system wide configuration" in section 2.
  75
  76
  77 ***********************************************************
  78 ** Section 2 * Installation from sources                 **
  79 ***********************************************************
  80
  81 * Prerequisites
  82
  83 Tools needed to follow the package download steps :
  84
  85 o wget
  86 o bzip2
  87 o gzip
  88 o tar
  89
  90 You have to install the standard development libraries and programs necessary
  91 to compile a kernel :
  92
  93 (from Documentation/Changes in the Linux kernel tree)
  94 o  Gnu C                  2.95.3                  # gcc --version
  95 o  Gnu make               3.79.1                  # make --version
  96 o  binutils               2.12                    # ld -v
  97 o  util-linux             2.10o                   # fdformat --version
  98 o  module-init-tools      0.9.10                  # depmod -V
  99
 100 You might also want to have libncurses5 to have the text mode kernel
 101 configuration menu, but there are alternatives.
 102
 103 Prerequisites for LTTV 0.x.x installation are :
 104
 105 gcc 3.2 or better
 106 gtk 2.4 or better development libraries
 107   (Debian : libgtk2.0, libgtk2.0-dev)
 108   (Fedora : gtk2, gtk2-devel)
 109   note : For Fedora users : this might require at least core 3 from Fedora,
 110   or you might have to compile your own GTK2 library.
 111 glib 2.4 or better development libraries
 112   (Debian : libglib2.0-0, libglib2.0-dev)
 113   (Fedora : glib2, glib2-devel)
 114 libpopt development libraries
 115   (Debian : libpopt0, libpopt-dev)
 116   (Fedora : popt)
 117 libpango development libraries
 118   (Debian : libpango1.0, libpango1.0-dev)
 119   (Fedora : pango, pango-devel)
 120 libc6 development librairies
 121   (Debian : libc6, libc6-dev)
 122   (Fedora : glibc, glibc)
 123
 124 * Reminder
 125
 126 See the list of compatibilities between LTTng, ltt-control, LTTV and
 127 markers-userspace at :
 128 http://ltt.polymtl.ca > LTTng+LTTV versions compatibility
 129
 130
 131
 132 * Getting the LTTng packages
 133
 134 su -
 135 mkdir /usr/src/lttng
 136 cd /usr/src/lttng
 137 (see http://ltt.polymtl.ca/lttng for package listing)
 138 wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
 139 bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 | tar xvof -
 140
 141
 142 * Getting LTTng kernel sources
 143
 144 su -
 145 cd /usr/src
 146 wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
 147 bzip2 -cd linux-2.6.X.tar.bz2 | tar xvof -
 148 cd linux-2.6.X
 149 - For LTTng 0.9.4- cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1
 150 - For LTTng 0.9.5+ apply the patches in the order specified in the series file,
 151   or use quilt
 152 cd ..
 153 mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
 154
 155
 156 * Installing a LTTng kernel
 157
 158 su -
 159 cd /usr/src/linux-2.6.X-lttng-0.x.xx
 160 make menuconfig (or make xconfig or make config)
 161     Select the < Help > button if you are not familiar with kernel
 162     configuration.
 163     Items preceded by [*] means they has to be built into the kernel.
 164     Items preceded by [M] means they has to be built as modules.
 165     Items preceded by [ ] means they should be removed.
 166   go to the "General setup" section
 167     Select the following options :
 168     [*] Activate tracepoints
 169     [*] Activate markers
 170     [*] Activate userspace markers ABI
 171     <*> Compile generic tracing probes
 172     Linux Trace Toolkit  --->
 173     [LTTng fine-grained-timestamping]
 174     [*] Linux Trace Toolkit Instrumentation Support
 175     <M> or <*> Linux Trace Toolkit Relay+DebugFS Support
 176     <M> or <*> Linux Trace Toolkit Serializer
 177     <M> or <*> Linux Trace Toolkit Marker Control
 178     <M> or <*> Linux Trace Toolkit Tracer
 179       It makes no difference for the rest of the procedure whether the Tracer
 180       is compiled built-in or as a module.
 181     activate :
 182        [*] Align Linux Trace Toolkit Traces
 183        <M> Linux Trace Toolkit Netlink Controller
 184        <M> Linux Trace Toolkit State Dump
 185     your choice (see < Help >) :
 186        [ ] Write heartbeat event to shrink traces
 187        [ ] Support trace extraction from crash dump
 188   Select <Exit>
 189   Select <Exit>
 190   Select <Yes>
 191 make
 192 make modules_install
 193 (if necessary, create a initrd with mkinitrd or your preferate alternative)
 194 (mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
 195
 196 -- on X86, X86_64
 197 make install
 198 reboot
 199 Select the Linux 2.6.17-lttng-0.x.xx kernel in your boot loader.
 200
 201 -- on PowerPC
 202 cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
 203 cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
 204 cp .config /boot/config-2.6.X-lttng-0.x.xx
 205 depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 206 mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 207 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
 208 that comes first is the default kernel)
 209 ybin
 210 select the right entry at the yaboot prompt (see choices : tab, select : type
 211 the kernel name followed by enter)
 212 Select the Linux 2.6.17-lttng-0.x.xx kernel in your boot loader.
 213 --
 214
 215
 216
 217 * Editing the system wide configuration
 218
 219 You must activate debugfs and specify a mount point. This is typically done in
 220 fstab such that it happens at boot time.
 221
 222 If you have never used DebugFS before, these operation would do this for you :
 223
 224 mkdir /mnt/debugfs
 225 cp /etc/fstab /etc/fstab.lttng.bkp
 226 echo "debugfs         /mnt/debugfs    debugfs rw              0       0"  >> /etc/fstab
 227
 228 then, rebooting or issuing the following command will activate debugfs :
 229
 230 mount /mnt/debugfs
 231
 232 You need to load the LTT modules to be able to control tracing from user
 233 space. This is done by issuing the following commands. Note however
 234 these commands load all LTT modules. Depending on what options you chose to
 235 compile statically, you may not need to issue all these commands.
 236
 237 modprobe ltt-trace-control
 238 modprobe ltt-marker-control
 239 modprobe ltt-tracer
 240 modprobe ltt-serialize
 241 modprobe ltt-relay
 242 modprobe ipc-trace
 243 modprobe kernel-trace
 244 modprobe mm-trace
 245 modprobe net-trace
 246 modprobe fs-trace
 247 modprobe syscall-trace
 248 modprobe trap-trace
 249 #if locking tracing is wanted, uncomment the following
 250 #modprobe lockdep-trace
 251
 252 If you want to have complete information about the kernel state (including all
 253 the process names), you need to load the ltt-statedump module. This is done by
 254 issuing the command :
 255
 256 modprobe ltt-statedump
 257
 258 You can automate at boot time loading the ltt-control module by :
 259
 260 cp /etc/modules /etc/modules.bkp
 261 echo ltt-trace-control >> /etc/modules
 262 echo ltt-marker-control >> /etc/modules
 263 echo ltt-tracer >> /etc/modules
 264 echo ltt-serialize >> /etc/modules
 265 echo ltt-relay >> /etc/modules
 266 echo ipc-trace >> /etc/modules
 267 echo kernel-trace >> /etc/modules
 268 echo mm-trace >> /etc/modules
 269 echo net-trace >> /etc/modules
 270 echo fs-trace >> /etc/modules
 271 #if locking tracing is wanted, uncomment the following
 272 #echo lockdep-trace >> /etc/modules
 273
 274
 275 * Getting and installing the ltt-control package (on the traced machine)
 276 (note : the ltt-control package contains lttd and lttctl. Although it has the
 277 same name as the ltt-control kernel module, they are *not* the same thing.)
 278 su -
 279 cd /usr/src
 280 wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
 281 gzip -cd ltt-control-0.x-xxxx2006.tar.gz | tar xvof -
 282 cd ltt-control-0.x-xxxx2006
 283 (refer to README to see the development libraries that must be installed on you
 284 system)
 285 ./configure
 286 make
 287 make install
 288
 289 * Getting and installing the markers-userspace package for user space tracing
 290 See http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2 or more recent.
 291
 292
 293 * Getting and installing the LTTV package (on the visualisation machine, same or
 294   different from the visualisation machine)
 295
 296 su -
 297 cd /usr/src
 298 wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
 299 gzip -cd lttv-0.x.xx-xxxx2008.tar.gz | tar xvof -
 300 cd lttv-0.x.xx-xxxx2008
 301 (refer to README to see the development libraries that must be installed on your
 302 system)
 303 ./configure
 304 make
 305 make install
 306
 307
 308
 309
 310 ***********************************************************
 311 ** Section 3 * Using LTTng and LTTV                      **
 312 ***********************************************************
 313
 314 * IMPORTANT : Arm Linux Kernel Markers after each boot
 315
 316 ltt-armall
 317
 318 * Use graphical LTTV to control tracing and analyse traces
 319
 320 lttv-gui (or /usr/local/bin/lttv-gui)
 321   - Spot the "Tracing Control" icon : click on it
 322       (it's a traffic light icon)
 323     - enter the root password
 324     - click "start"
 325     - click "stop"
 326     - Yes
 327       * You should now see a trace
 328
 329 * Use text mode LTTng to control tracing
 330
 331 The tracing can be controlled from a terminal by using the lttctl command (as
 332 root).
 333
 334 Start tracing :
 335
 336 lttctl -C -w /tmp/trace1 trace1
 337
 338 Stop tracing and destroy trace channels :
 339
 340 lttctl -D trace1
 341
 342 see lttctl --help for details.
 343
 344 (note : to see if the buffers has been filled, look at the dmesg output after
 345 lttctl -R or after stopping tracing from the GUI, it will show an event lost
 346 count. If it is the case, try using larger buffers. See lttctl --help to learn
 347 how. lttv now also shows event lost messages in the console when loading a trace
 348 with missing events or lost subbuffers.)
 349
 350 * Use text mode LTTV
 351
 352 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
 353 graphical plugins available.
 354
 355 For example, a simple trace dump in text format is available with :
 356
 357 lttv -m textDump -t /tmp/trace
 358
 359 see lttv -m textDump --help for detailed command line options of textDump.
 360
 361 It is, in the current state of the project, very useful to use "grep" on the
 362 text output to filter by specific event fields. You can later copy the timestamp
 363 of the events to the clipboard and paste them in the GUI by clicking on the
 364 bottom right label "Current time". Support for this type of filtering should
 365 be added to the filter module soon.
 366
 367 * Hybrid mode
 368
 369 Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
 370 hybrid. It can be especially useful when studying big workloads on a long period
 371 of time.
 372
 373 When using this mode, the most important, low rate control information will be
 374 recorded during all the trace by lttd (i.e. process creation/exit). The high
 375 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
 376 flight recorder buffer (now named flight-channelname_X).
 377
 378 The following lttctl commands take an hybrid trace :
 379
 380 Create trace channel, start lttd on normal channels, start tracing:
 381 lttctl -C -w /tmp/trace2 -o channel.kernel.overwrite=1 trace2
 382
 383 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
 384 lttctl -D -w /tmp/trace2 trace2
 385
 386 Each "overwrite" channel is flight recorder channel.
 387
 388 * Flight recorder mode
 389
 390 The flight recorder mode writes data into overwritten buffers for all channels,
 391 including control channels, except for the facilities tracefiles. It consists of
 392 setting all channels to "overwrite".
 393
 394 The following lttctl commands take a flight recorder trace :
 395
 396 lttctl -C -w /tmp/trace3 -o channel.all.overwrite=1 trace3
 397 ...
 398 lttctl -D -w /tmp/trace3 trace3
 399
 400
 401 **************************************************************
 402 ** Section 4 * Adding new instrumentations with the markers **
 403 **************************************************************
 404
 405 See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
 406 tree.
 407
 408 * Add new events to userspace programs with userspace markers
 409 http://ltt.polymtl.ca/packages/
 410
 411 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
 412 allows inserting markers in executables and libraries, currently only on x86_32
 413 and x86_64.
 414