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