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 0.12 tracer on a linux 2.6.X
  18 kernel. You will also find instructions for installation of LTTV 0.8.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
 125 * Getting the LTTng packages
 126
 127 su -
 128 mkdir /usr/src/lttng
 129 cd /usr/src/lttng
 130 (see http://ltt.polymtl.ca/lttng for package listing)
 131 wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2
 132 bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 | tar xvof -
 133
 134
 135 * Getting LTTng kernel sources
 136
 137 su -
 138 cd /usr/src
 139 wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2
 140 bzip2 -cd linux-2.6.X.tar.bz2 | tar xvof -
 141 cd linux-2.6.X
 142 - For LTTng 0.9.4- cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1
 143 - For LTTng 0.9.5+ apply the patches in the order specified in the series file,
 144   or use quilt
 145 cd ..
 146 mv linux-2.6.X linux-2.6.X-lttng-0.x.xx
 147
 148
 149 * Installing a LTTng kernel
 150
 151 su -
 152 cd /usr/src/linux-2.6.X-lttng-0.x.xx
 153 make menuconfig (or make xconfig or make config)
 154     Select the < Help > button if you are not familiar with kernel
 155     configuration.
 156     Items preceded by [*] means they has to be built into the kernel.
 157     Items preceded by [M] means they has to be built as modules.
 158     Items preceded by [ ] means they should be removed.
 159   go to the "General setup" section
 160     Select the following options :
 161     [*] Activate tracepoints
 162     [*] Activate markers
 163     [*] Activate userspace markers ABI
 164     <*> Compile generic tracing probes
 165     Linux Trace Toolkit  --->
 166     [LTTng fine-grained-timestamping]
 167     [*] Linux Trace Toolkit Instrumentation Support
 168     <M> or <*> Linux Trace Toolkit Relay+DebugFS Support
 169     <M> or <*> Linux Trace Toolkit Serializer
 170     <M> or <*> Linux Trace Toolkit Marker Control
 171     <M> or <*> Linux Trace Toolkit Tracer
 172       It makes no difference for the rest of the procedure whether the Tracer
 173       is compiled built-in or as a module.
 174     activate :
 175        [*] Align Linux Trace Toolkit Traces
 176        <M> Linux Trace Toolkit Netlink Controller
 177        <M> Linux Trace Toolkit State Dump
 178     your choice (see < Help >) :
 179        [ ] Write heartbeat event to shrink traces
 180        [ ] Support trace extraction from crash dump
 181   Select <Exit>
 182   Select <Exit>
 183   Select <Yes>
 184 make
 185 make modules_install
 186 (if necessary, create a initrd with mkinitrd or your preferate alternative)
 187 (mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx)
 188
 189 -- on X86, X86_64
 190 make install
 191 reboot
 192 Select the Linux 2.6.17-lttng-0.x.xx kernel in your boot loader.
 193
 194 -- on PowerPC
 195 cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx
 196 cp System.map /boot/System.map-2.6.X-lttng-0.x.xx
 197 cp .config /boot/config-2.6.X-lttng-0.x.xx
 198 depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 199 mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx
 200 (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry
 201 that comes first is the default kernel)
 202 ybin
 203 select the right entry at the yaboot prompt (see choices : tab, select : type
 204 the kernel name followed by enter)
 205 Select the Linux 2.6.17-lttng-0.x.xx kernel in your boot loader.
 206 --
 207
 208
 209
 210 * Editing the system wide configuration
 211
 212 You must activate debugfs and specify a mount point. This is typically done in
 213 fstab such that it happens at boot time.
 214
 215 If you have never used DebugFS before, these operation would do this for you :
 216
 217 mkdir /mnt/debugfs
 218 cp /etc/fstab /etc/fstab.lttng.bkp
 219 echo "debugfs         /mnt/debugfs    debugfs rw              0       0"  >> /etc/fstab
 220
 221 then, rebooting or issuing the following command will activate debugfs :
 222
 223 mount /mnt/debugfs
 224
 225 You need to load the LTT modules to be able to control tracing from user
 226 space. This is done by issuing the following commands. Note however
 227 these commands load all LTT modules. Depending on what options you chose to
 228 compile statically, you may not need to issue all these commands.
 229
 230 modprobe ltt-control
 231 modprobe ltt-marker-control
 232 modprobe ltt-tracer
 233 modprobe ltt-serialize
 234 modprobe ltt-relay
 235 modprobe ipc-trace
 236 modprobe kernel-trace
 237 modprobe mm-trace
 238 modprobe net-trace
 239 modprobe fs-trace
 240
 241 If you want to have complete information about the kernel state (including all
 242 the process names), you need to load the ltt-statedump module. This is done by
 243 issuing the command :
 244
 245 modprobe ltt-statedump
 246
 247 You can automate at boot time loading the ltt-control module by :
 248
 249 cp /etc/modules /etc/modules.bkp
 250 echo ltt-control >> /etc/modules
 251 echo ltt-marker-control >> /etc/modules
 252 echo ltt-tracer >> /etc/modules
 253 echo ltt-serialize >> /etc/modules
 254 echo ltt-relay >> /etc/modules
 255 echo ipc-trace >> /etc/modules
 256 echo kernel-trace >> /etc/modules
 257 echo mm-trace >> /etc/modules
 258 echo net-trace >> /etc/modules
 259 echo fs-trace >> /etc/modules
 260
 261
 262 * Getting and installing the ltt-control package (on the traced machine)
 263 (note : the ltt-control package contains lttd and lttctl. Although it has the
 264 same name as the ltt-control kernel module, they are *not* the same thing.)
 265 su -
 266 cd /usr/src
 267 wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz
 268 gzip -cd ltt-control-0.x-xxxx2006.tar.gz | tar xvof -
 269 cd ltt-control-0.x-xxxx2006
 270 (refer to README to see the development libraries that must be installed on you
 271 system)
 272 ./configure
 273 make
 274 make install
 275
 276 * Getting and installing the markers-userspace package for user space tracing
 277 See http://ltt.polymtl.ca/packages/markers-userspace-0.5.tar.bz2 or more recent.
 278
 279
 280 * Getting and installing the LTTV package (on the visualisation machine, same or
 281   different from the visualisation machine)
 282
 283 su -
 284 cd /usr/src
 285 wget http://ltt.polymtl.ca/packages/lttv-0.x.xx-xxxx2008.tar.gz
 286 gzip -cd lttv-0.x.xx-xxxx2008.tar.gz | tar xvof -
 287 cd lttv-0.x.xx-xxxx2008
 288 (refer to README to see the development libraries that must be installed on your
 289 system)
 290 ./configure
 291 make
 292 make install
 293
 294
 295
 296
 297 ***********************************************************
 298 ** Section 3 * Using LTTng and LTTV                      **
 299 ***********************************************************
 300
 301 * IMPORTANT : Arm Linux Kernel Markers after each boot
 302
 303 ltt-armall
 304
 305 * Use graphical LTTV to control tracing and analyse traces
 306
 307 lttv-gui (or /usr/local/bin/lttv-gui)
 308   - Spot the "Tracing Control" icon : click on it
 309       (it's a traffic light icon)
 310     - enter the root password
 311     - click "start"
 312     - click "stop"
 313     - Yes
 314       * You should now see a trace
 315
 316 * Use text mode LTTng to control tracing
 317
 318 The tracing can be controlled from a terminal by using the lttctl command (as
 319 root).
 320
 321 Start tracing :
 322
 323 lttctl -n trace -d -l /mnt/debugfs/ltt -t /tmp/trace
 324
 325 Stop tracing and destroy trace channels :
 326
 327 lttctl -n trace -R
 328
 329 see lttctl --help for details.
 330
 331 (note : to see if the buffers has been filled, look at the dmesg output after
 332 lttctl -R or after stopping tracing from the GUI, it will show an event lost
 333 count. If it is the case, try using larger buffers. See lttctl --help to learn
 334 how.)
 335
 336 * Use text mode LTTV
 337
 338 Feel free to look in /usr/local/lib/lttv/plugins to see all the text and
 339 graphical plugins available.
 340
 341 For example, a simple trace dump in text format is available with :
 342
 343 lttv -m textDump -t /tmp/trace
 344
 345 see lttv -m textDump --help for detailed command line options of textDump.
 346
 347 It is, in the current state of the project, very useful to use "grep" on the
 348 text output to filter by specific event fields. You can later copy the timestamp
 349 of the events to the clipboard and paste them in the GUI by clicking on the
 350 bottom right label "Current time". Support for this type of filtering should
 351 be added to the filter module soon.
 352
 353 * Hybrid mode
 354
 355 Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used :
 356 hybrid. It can be especially useful when studying big workloads on a long period
 357 of time.
 358
 359 When using this mode, the most important, low rate control information will be
 360 recorded during all the trace by lttd (i.e. process creation/exit). The high
 361 rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a
 362 flight recorder buffer (now named flight-channelname_X).
 363
 364 The following lttctl commands take an hybrid trace :
 365
 366 Create trace channel, start lttd on normal channels, start tracing:
 367 lttctl -n tracename -d -l /mnt/debugfs/ltt -t /tmp/trace1 -m hybrid
 368
 369 Stop tracing, start lttd on flight recorder channels, destroy trace channels :
 370 lttctl -n tracename -f -l /mnt/debugfs/ltt -t /tmp/trace1 -m hybrid
 371
 372
 373 We will need to tweak what we consider "important" medium rate events. For
 374 instance, thread branding events are actually considered a "high rate" event
 375 when it should be considered "medium rate". The same should apply for the
 376 state dump process enumeration.
 377
 378 * Flight recorder mode
 379
 380 The flight recorder mode writes data into overwritten buffers for all channels,
 381 including control channels, except for the facilities tracefiles.
 382
 383 The following lttctl commands take a flight recorder trace :
 384
 385 lttctl -n trace -c -m flight
 386 lttd -n -d -t /tmp/trace -c /mnt/debugfs/ltt/trace
 387 lttctl -n trace -s
 388 .. do stuff
 389 lttctl -n trace -q
 390 lttd -f -d -t /tmp/trace -c /mnt/debugfs/ltt/trace
 391 lttctl -m trace -r
 392
 393
 394 **************************************************************
 395 ** Section 4 * Adding new instrumentations with the markers **
 396 **************************************************************
 397
 398 See Documentation/markers.txt and Documentation/tracepoints.txt in your kernel
 399 tree.
 400
 401 * Add new events to userspace programs with userspace markers
 402 http://ltt.polymtl.ca/packages/
 403
 404 Get the latest markers-userspace-*.tar.bz2 and see the Makefile and examples. It
 405 allows inserting markers in executables and libraries, currently only on x86_32
 406 and x86_64.
 407