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1 | Linux Trace Toolkit Quickstart |
2 | ------------------------------ |
3 | Author : Mathieu Desnoyers, September 2005 |
4 | Last update : May 14, 2007 |
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5 | |
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6 | |
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7 | This document is made of four parts : the first one explains how to install |
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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 |
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11 | briefly how to add a new trace point to the kernel and to user space |
12 | applications. |
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13 | |
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14 | What you will typically want is to read sections 2 and 3 : install LTTng from |
15 | sources and use it. |
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16 | |
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17 | These operations are made for installing the LTTng 0.6.X tracer on a |
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18 | linux 2.6.X kernel. You will also find instructions for installation of |
19 | LTTV 0.8.x : the Linux Trace Toolkit Viewer. |
20 | |
21 | To see the list of compatibilities between LTTng, ltt-control, LTTV, genevent |
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22 | and ltt-usertrace, please refer to : |
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23 | http://ltt.polymtl.ca > LTTng+LTTV versions compatibility |
24 | |
25 | |
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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 | |
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30 | Required programs and libraries are assumed to be automatically installed in an |
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31 | installation with Debian or RPM packages. In the case of an installation from |
32 | sources, the dependencies are listed. |
33 | |
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34 | |
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35 | ** Current development status ** |
36 | |
37 | LTTng : |
38 | supported architectures : |
39 | Intel Pentium (UP/SMP) with TSC |
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40 | PowerPC 32 and 64 bits |
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41 | ARM |
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42 | x86_64 |
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43 | C2 Microsystems (variant of MIPS) |
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44 | |
45 | LTTV : |
46 | supported architectures : |
47 | Intel i386 and better |
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48 | Intel 64 bits |
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49 | PowerPC 32 and 64 bits |
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50 | |
51 | |
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52 | *********************************************************** |
53 | ** Section 1 * Installation from Debian or RPM packages ** |
54 | *********************************************************** |
55 | |
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56 | ** NOTE : RPM and Debian packages are only made once a version has been |
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57 | thoroughly tested. If they do not exist at the moment, please install from |
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58 | sources (see section 2 below). To see the list of compatibilities between |
59 | LTTng, ltt-control, LTTV, genevent and lttng-modules, please refer to |
60 | http://ltt.polymtl.ca > LTTng+LTTV versions compatibility |
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61 | |
62 | |
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63 | * Install from RPM packages on Fedora Core 4 : |
64 | |
65 | Get LTTV RPM from : |
66 | |
67 | http://ltt.polymtl.ca/packages/fedora/RPMS |
68 | |
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69 | LTTV RPM are ready. |
70 | |
71 | LTTng kernel and lttng-modules RPM are available for some architectures (i586, |
72 | i686). Feel free to help fix the spec files to have correct lttng-modules RPM |
73 | package. |
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74 | |
75 | |
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76 | * Install from .deb packages on Debian : |
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77 | |
78 | You can use the ltt.polymtl.ca apt source to get LTTV for Debian : |
79 | |
80 | Add the following two sources to your /etc/apt/sources.list : |
81 | |
82 | deb http://ltt.polymtl.ca/packages/debian experimental main |
83 | deb-src http://ltt.polymtl.ca/packages/debian experimental main |
84 | |
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85 | |
86 | * Install from precompiled binary packages (LTTV compiled only for i386, and |
87 | LTTng only for i686 smp), perform the following : |
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88 | |
89 | su - |
90 | apt-get update |
91 | apt-get install lttv lttv-doc |
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92 | apt-get install kernel-image-2.6.12-rc4-mm2-lttng-0.4.2 |
93 | apt-get install lttng-modules-modules-2.6.12-rc4-mm2-lttng-0.4.2 |
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94 | * note : the packages are signed by myself. I am not considered a trusted |
95 | Debian source yet, so warnings are normal. |
96 | |
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97 | Then, follow the section "Editing the system wide configuration" in section 2. |
98 | |
99 | * Create custom LTTV Debian packages |
100 | |
101 | Binary packages are only available for i386. If you want to create your own LTTV |
102 | packages for other platforms, do : |
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103 | |
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104 | su - |
105 | cd /usr/src |
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106 | apt-get source lttv |
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107 | cd lttv-0.6.9 |
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108 | dpkg-buildpackage -rfakeroot |
109 | |
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110 | You should then have your LTTV .deb files created for your architecture. |
111 | |
112 | * Create custom LTTng packages |
113 | |
114 | For building LTTng Debian packages : |
115 | |
116 | su - |
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117 | apt-get install kernel-source-2.6.12-rc4-mm2-lttng-0.4.2 |
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118 | cd /usr/src |
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119 | bzip2 -cd kernel-source-2.6.12-rc4-mm2-lttng-0.4.2.tar.bz2 | tar xvof - |
120 | cd kernel-source-2.6.12-rc4-mm2-lttng-0.4.2 |
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121 | make menuconfig (or xconfig or config) (customize your configuration) |
122 | make-kpkg kernel_image |
123 | |
124 | You will then see your freshly created .deb in /usr/src. Install it with |
125 | dpkg -i /usr/src/(image-name).deb |
126 | |
127 | You will also need to create a package for the lttng-modules : |
128 | |
129 | su - |
130 | cd /usr/src |
131 | apt-get source lttng-modules |
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132 | cd kernel-source-2.6.12-rc4-mm2-lttng-0.4.2 |
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133 | make-kpkg --added_modules /usr/src/lttng-modules-0.3 modules_image |
134 | |
135 | You will then see your freshly created .deb in /usr/src. Install it with |
136 | dpkg -i /usr/src/lttng-modules-modules-(your version).deb |
137 | |
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138 | |
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139 | Then, follow the section "Editing the system wide configuration" in section 2. |
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140 | |
141 | |
142 | *********************************************************** |
143 | ** Section 2 * Installation from sources ** |
144 | *********************************************************** |
145 | |
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146 | * Prerequisites |
147 | |
148 | Tools needed to follow the package download steps : |
149 | |
150 | o wget |
151 | o bzip2 |
152 | o gzip |
153 | o tar |
154 | |
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155 | You have to install the standard development libraries and programs necessary |
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156 | to compile a kernel : |
157 | |
158 | (from Documentation/Changes in the Linux kernel tree) |
159 | o Gnu C 2.95.3 # gcc --version |
160 | o Gnu make 3.79.1 # make --version |
161 | o binutils 2.12 # ld -v |
162 | o util-linux 2.10o # fdformat --version |
163 | o module-init-tools 0.9.10 # depmod -V |
164 | |
165 | You might also want to have libncurses5 to have the text mode kernel |
166 | configuration menu, but there are alternatives. |
167 | |
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168 | Prerequisites for LTTV 0.x.x installation are : |
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169 | |
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170 | gcc 3.2 or better |
171 | gtk 2.4 or better development libraries |
172 | (Debian : libgtk2.0, libgtk2.0-dev) |
173 | (Fedora : gtk2, gtk2-devel) |
174 | note : For Fedora users : this might require at least core 3 from Fedora, |
175 | or you might have to compile your own GTK2 library. |
176 | glib 2.4 or better development libraries |
177 | (Debian : libglib2.0-0, libglib2.0-dev) |
178 | (Fedora : glib2, glib2-devel) |
179 | libpopt development libraries |
180 | (Debian : libpopt0, libpopt-dev) |
181 | (Fedora : popt) |
182 | libpango development libraries |
183 | (Debian : libpango1.0, libpango1.0-dev) |
184 | (Fedora : pango, pango-devel) |
185 | libc6 development librairies |
186 | (Debian : libc6, libc6-dev) |
187 | (Fedora : glibc, glibc) |
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188 | |
189 | |
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190 | * Getting the LTTng packages |
191 | |
192 | su - |
193 | mkdir /usr/src/lttng |
194 | cd /usr/src/lttng |
195 | (see http://ltt.polymtl.ca/lttng for package listing) |
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196 | wget http://ltt.polymtl.ca/lttng/patch-2.6.X-lttng-0.x.xx.tar.bz2 |
197 | bzip2 -cd patch-2.6.X-lttng-0.x.xx.tar.bz2 | tar xvof - |
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198 | |
199 | |
200 | * Getting LTTng kernel sources |
201 | |
202 | su - |
203 | cd /usr/src |
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204 | wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.X.tar.bz2 |
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205 | bzip2 -cd linux-2.6.X.tar.bz2 | tar xvof - |
206 | cd linux-2.6.X |
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207 | - For LTTng 0.9.4- cat /usr/src/lttng/patch*-2.6.X-lttng-0.x.xx* | patch -p1 |
208 | - For LTTng 0.9.5+ apply the patches in the order specified in the series file, |
209 | or use quilt |
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210 | cd .. |
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211 | mv linux-2.6.X linux-2.6.X-lttng-0.x.xx |
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212 | |
213 | |
214 | * Installing a LTTng kernel |
215 | |
216 | su - |
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217 | cd /usr/src/linux-2.6.X-lttng-0.x.xx |
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218 | make menuconfig (or make xconfig or make config) |
219 | Select the < Help > button if you are not familiar with kernel |
220 | configuration. |
221 | Items preceded by [*] means they has to be built into the kernel. |
222 | Items preceded by [M] means they has to be built as modules. |
223 | Items preceded by [ ] means they should be removed. |
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224 | go to the "Instrumentation Support" section |
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225 | Select the following options : |
226 | [*] Linux Trace Toolkit Instrumentation Support |
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227 | <M> or <*> Linux Trace Toolkit Tracer |
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228 | <M> or <*> Linux Trace Toolkit Relay+DebugFS Support |
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229 | It makes no difference for the rest of the procedure whether the Tracer |
230 | is compiled built-in or as a module. |
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231 | activate : |
232 | [*] Align Linux Trace Toolkit Traces |
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233 | [*] Allow tracing from userspace |
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234 | <M> Linux Trace Toolkit Netlink Controller |
235 | <M> Linux Trace Toolkit State Dump |
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236 | your choice (see < Help >) : |
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237 | [ ] Activate Linux Trace Toolkit Heartbeat Timer |
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238 | You may or may not decide to compile probes. Afterward, you will have to |
239 | load the probe modules to enable tracing of their events. The probes |
240 | automatically select the appropriate facilities. |
241 | Static instrumentation is a more invasive type of instrumentation that gives |
242 | the address taking a lock or doing a printk. |
243 | Select <Exit> |
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244 | Select <Exit> |
245 | Select <Yes> |
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246 | make |
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247 | make modules_install |
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248 | (if necessary, create a initrd with mkinitrd or your preferate alternative) |
249 | (mkinitrd -o /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx) |
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250 | |
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251 | -- on X86, X86_64 |
252 | make install |
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253 | reboot |
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254 | Select the Linux 2.6.17-lttng-0.x.xx kernel in your boot loader. |
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255 | |
256 | -- on PowerPC |
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257 | cp vmlinux.strip /boot/vmlinux-2.6.X-lttng-0.x.xx |
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258 | cp System.map /boot/System.map-2.6.X-lttng-0.x.xx |
259 | cp .config /boot/config-2.6.X-lttng-0.x.xx |
260 | depmod -ae -F /boot/System.map-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx |
261 | mkinitrd /boot/initrd.img-2.6.X-lttng-0.x.xx 2.6.X-lttng-0.x.xx |
262 | (edit /etc/yaboot.conf to add a new entry pointing to your kernel : the entry |
263 | that comes first is the default kernel) |
264 | ybin |
265 | select the right entry at the yaboot prompt (see choices : tab, select : type |
266 | the kernel name followed by enter) |
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267 | Select the Linux 2.6.17-lttng-0.x.xx kernel in your boot loader. |
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268 | -- |
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269 | |
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270 | |
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271 | |
272 | * Editing the system wide configuration |
273 | |
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274 | You must activate debugfs and specify a mount point. This is typically done in |
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275 | fstab such that it happens at boot time. |
276 | |
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277 | If you have never used DebugFS before, these operation would do this for you : |
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278 | |
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279 | mkdir /mnt/debugfs |
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280 | cp /etc/fstab /etc/fstab.lttng.bkp |
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281 | echo "debugfs /mnt/debugfs debugfs rw 0 0" >> /etc/fstab |
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282 | |
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283 | then, rebooting or issuing the following command will activate debugfs : |
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284 | |
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285 | mount /mnt/debugfs |
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286 | |
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287 | You need to load the LTT modules to be able to control tracing from user |
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288 | space. This is done by issuing the following commands. Note however |
289 | these commands load all LTT modules. Depending on what options you chose to |
290 | compile statically, you may not need to issue all these commands. |
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291 | |
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292 | modprobe ltt-control |
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293 | modprobe ltt-core |
294 | modprobe ltt-relay |
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295 | modprobe ltt-tracer |
296 | modprobe ltt-probe-mm |
297 | modprobe ltt-probe-kernel |
298 | modprobe ltt-probe-i386 (or x86_64, powerpc, ppc, arm, mips) |
299 | modprobe ltt-probe-net |
300 | modprobe ltt-probe-list |
301 | modprobe ltt-probe-ipc |
302 | modprobe ltt-probe-fs |
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303 | |
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304 | If you want to have complete information about the kernel state (including all |
305 | the process names), you need to load the ltt-statedump module. This is done by |
306 | issuing the command : |
307 | |
308 | modprobe ltt-statedump |
309 | |
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310 | You can automate at boot time loading the ltt-control module by : |
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311 | |
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312 | cp /etc/modules /etc/modules.bkp |
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313 | echo ltt-control >> /etc/modules |
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314 | echo ltt-core >> /etc/modules |
315 | echo ltt-relay >> /etc/modules |
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316 | echo ltt-tracer >> /etc/modules |
317 | echo ltt-probe-mm >> /etc/modules |
318 | echo ltt-probe-kernel >> /etc/modules |
319 | echo ltt-probe-i386 >> /etc/modules (or x86_64, powerpc, ppc, arm, mips) |
320 | echo ltt-probe-net >> /etc/modules |
321 | echo ltt-probe-list >> /etc/modules |
322 | echo ltt-probe-ipc >> /etc/modules |
323 | echo ltt-probe-fs >> /etc/modules |
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324 | echo ltt-statedump >> /etc/modules |
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325 | |
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326 | (note : if you want to probe a marker which is within a module, make sure you |
327 | load the probe _after_ the module, otherwise the probe will not be able to |
328 | connect itself to the marker.) |
329 | |
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330 | |
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331 | * Getting and installing the ltt-control package (on the traced machine) |
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332 | (note : the ltt-control package contains lttd and lttctl. Although it has the |
333 | same name as the ltt-control kernel module, they are *not* the same thing.) |
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334 | su - |
335 | cd /usr/src |
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336 | wget http://ltt.polymtl.ca/lttng/ltt-control-0.x-xxxx2006.tar.gz |
337 | gzip -cd ltt-control-0.x-xxxx2006.tar.gz | tar xvof - |
338 | cd ltt-control-0.x-xxxx2006 |
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339 | (refer to README to see the development libraries that must be installed on you |
340 | system) |
341 | ./configure |
342 | make |
343 | make install |
344 | |
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345 | * Getting and installing the ltt-usertrace package for user space tracing |
346 | See http://ltt.polymtl.ca/ > USERSPACE TRACING QUICKSTART |
347 | |
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348 | |
349 | * Getting and installing the LTTV package (on the visualisation machine, same or |
350 | different from the visualisation machine) |
351 | |
352 | su - |
353 | cd /usr/src |
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354 | wget http://ltt.polymtl.ca/packages/LinuxTraceToolkitViewer-0.x.xx-xxxx2006.tar.gz |
355 | gzip -cd LinuxTraceToolkitViewer-0.x.xx-xxxx2006.tar.gz | tar xvof - |
356 | cd LinuxTraceToolkitViewer-0.x.xx-xxxx2006 |
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357 | (refer to README to see the development libraries that must be installed on your |
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358 | system) |
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359 | ./configure |
360 | make |
361 | make install |
362 | |
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363 | |
364 | |
365 | |
366 | *********************************************************** |
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367 | ** Section 3 * Using LTTng and LTTV ** |
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368 | *********************************************************** |
369 | |
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370 | * Arm Linux Kernel Markers after each boot |
371 | |
372 | ltt-armall |
373 | |
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374 | * Use graphical LTTV to control tracing and analyse traces |
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375 | |
376 | lttv-gui (or /usr/local/bin/lttv-gui) |
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377 | - Spot the "Tracing Control" icon : click on it |
378 | (it's a traffic light icon) |
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379 | - enter the root password |
380 | - click "start" |
381 | - click "stop" |
382 | - Yes |
383 | * You should now see a trace |
384 | |
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385 | * Use text mode LTTng to control tracing |
386 | |
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387 | The tracing can be controlled from a terminal by using the lttctl command (as |
388 | root). |
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389 | |
390 | Start tracing : |
391 | |
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392 | lttctl -n trace -d -l /mnt/debugfs/ltt -t /tmp/trace |
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393 | |
394 | Stop tracing and destroy trace channels : |
395 | |
396 | lttctl -n trace -R |
397 | |
398 | see lttctl --help for details. |
399 | |
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400 | (note : to see if the buffers has been filled, look at the dmesg output after |
401 | lttctl -R or after stopping tracing from the GUI, it will show an event lost |
402 | count. If it is the case, try using larger buffers. See lttctl --help to learn |
403 | how.) |
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404 | |
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405 | * Use text mode LTTV |
406 | |
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407 | Feel free to look in /usr/local/lib/lttv/plugins to see all the text and |
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408 | graphical plugins available. |
409 | |
410 | For example, a simple trace dump in text format is available with : |
411 | |
412 | lttv -m textDump -t /tmp/trace |
413 | |
414 | see lttv -m textDump --help for detailed command line options of textDump. |
415 | |
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416 | It is, in the current state of the project, very useful to use "grep" on the |
417 | text output to filter by specific event fields. You can later copy the timestamp |
418 | of the events to the clipboard and paste them in the GUI by clicking on the |
419 | bottom right label "Current time". Support for this type of filtering should |
420 | be added to the filter module soon. |
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421 | |
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422 | * Hybrid mode |
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423 | |
424 | Starting from LTTng 0.5.105 and ltt-control 0.20, a new mode can be used : |
425 | hybrid. It can be especially useful when studying big workloads on a long period |
426 | of time. |
427 | |
428 | When using this mode, the most important, low rate control information will be |
429 | recorded during all the trace by lttd (i.e. process creation/exit). The high |
430 | rate information (i.e. interrupt/traps/syscall entry/exit) will be kept in a |
431 | flight recorder buffer (now named flight-channelname_X). |
432 | |
433 | The following lttctl commands take an hybrid trace : |
434 | |
435 | Create trace channel, start lttd on normal channels, start tracing: |
436 | lttctl -n tracename -d -l /mnt/relayfs/ltt -t /tmp/trace1 -m hybrid |
437 | |
438 | Stop tracing, start lttd on flight recorder channels, destroy trace channels : |
439 | lttctl -n tracename -f -l /mnt/relayfs/ltt -t /tmp/trace1 -m hybrid |
440 | |
441 | |
442 | We will need to tweak what we consider "important" medium rate events. For |
443 | instance, thread branding events are actually considered a "high rate" event |
444 | when it should be considered "medium rate". The same should apply for the |
445 | state dump process enumeration. |
446 | |
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447 | * Flight recorder mode |
448 | |
449 | The flight recorder mode writes data into overwritten buffers for all channels, |
450 | including control channels, except for the facilities tracefiles. |
451 | |
452 | The following lttctl commands take a flight recorder trace : |
453 | |
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454 | lttctl -n trace -c -m flight |
455 | lttd -n -d -t /tmp/trace -c /sys/kernel/debug/ltt |
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456 | lttctl -n trace -s |
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457 | .. do stuff |
458 | lttctl -n trace -q |
459 | lttd -f -d -t /tmp/trace -c /sys/kernel/debug/ltt |
460 | lttctl -m trace -r |
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461 | |
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462 | |
463 | *********************************************************** |
464 | ** Section 4 * Adding new instrumentations with genevent ** |
465 | *********************************************************** |
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466 | |
467 | * Getting and installing genevent |
468 | |
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469 | su - |
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470 | cd /usr/src |
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471 | wget http://ltt.polymtl.ca/packages/genevent-0.xx.tar.gz |
472 | gzip -cd genevent-0.xx.tar.gz | tar xvof - |
473 | cd genevent-0.xx |
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474 | make |
475 | make install |
476 | |
477 | |
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478 | * Add new events to the kernel with genevent (deprecated in LTTng 0.9.x) |
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479 | |
480 | su - |
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481 | cd /usr/local/share/ltt-control/facilities |
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482 | cp process.xml yourfacility.xml |
483 | * edit yourfacility.xml to fit your needs. |
484 | cd /tmp |
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485 | /usr/local/bin/genevent /usr/local/share/ltt-control/facilities/yourfacility.xml |
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486 | cp ltt-facility-yourfacility.h ltt-facility-id-yourfacility.h \ |
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487 | /usr/src/linux-2.6.17-lttng-0.x.xx8/include/ltt |
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488 | cp ltt-facility-loader-yourfacility.c ltt-facility-loader-yourfacility.h \ |
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489 | /usr/src/linux-2.6.17-lttng-0.x.xx/ltt/facilities |
490 | * edit the kernel file you want to instrument to add a marker to it. See |
491 | include/linux/marker.h. |
492 | * create a dynamically loadable probe. See ltt/probes for examples. The probe |
493 | will be connected to your marker and will typically call the logging |
494 | functions found in the header file you created with genevent. |
495 | |
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496 | * Add new kernel events |
497 | |
498 | *Important* note : in its current state, LTTng and LTTV needs the programmer |
499 | to keep the marker/probe format string and the XML description of the |
500 | event data types in sync by hand. Failure to do so will result in errors in |
501 | LTTV. |
502 | |
503 | See the markers documentation to see how to describe the marker. You will need |
504 | to clone probe modules found in ltt/probes to connect them to the markers so |
505 | that the information can be recorded in the trace. |
506 | |
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507 | * Add new events to userspace programs with genevent |
508 | See http://ltt.polymtl.ca/ > USERSPACE TRACING QUICKSTART |
509 | |
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510 | User-space tracing still uses genevent, which is subject to change in a near |
511 | future. |