* Build the sample programs and install the headers and librairies into your
system :
+(32 bits)
su
-cd /usr/src/usertrace-generic
+cd /usr/src/ltt-usertrace
+make clean
+make install (will build and install headers and libraries)
make
-make install
+(64 bits)
+su
+cd /usr/src/ltt-usertrace
+make clean
+LIB_DIR=/usr/lib64 make install CFLAGS=-m64
+make CFLAGS=-m64
Feel free to look at the sample programs and the Makefile : they demonstrate
very well the features of the usertrace package and how to use them.
-* There are three ways to trace information from your application :
+* There are three ways to trace information from your application. The choice
+ will principally depend on the trace data rate.
1) Easy way, but slow (printf style)
See sample-printf.c for code example.
-2) The second way to log events is still easy, yet faster. It requires creating
- your own XML description of your data structures. It will make it easier to
- identify your data in the trace. Please read the comments in method 1)
- explained previously, as they are not repeated here.
- See sample.c for code example.
+2) The second way to log events is still easy. The advantage is that it
+ will make it easier to identify your data in the trace viewer afterward.
+ Please read the comments in method 1) explained previously, as they
+ are not repeated here.
+ See sample.c and sample-thread-slow.c for code example.
-- Go to the usertrace-generic directory
+- Go to the ltt-usertrace directory
su
-cd /usr/src/usertrace-generic
+cd /usr/src/ltt-usertrace
- Create your own facility (i.e. user_myfacility.xml).
See the ones available in /usr/share/LinuxTraceToolkitViewer/facilities for
user_myfacility.xml:
+<?xml version="1.0"?>
<facility name="user_myfacility">
<description>Sample facility</description>
<event name="myevent">
user_myfacility.myevent: 39507.805584526 (/cpu_1), 15829, 15736, SYSCALL { "myapp.c", "main", 8, 1234, 0xf0f0f0f0 }
+3) The third way to trace information from your application
+
+This method is cleary the _FASTEST_. It is principally I/O (disk and memory)
+bound. It will create a companion process for each of you program's thread which
+will dump the tracing information into /tmp/ltt-usertrace.
+
+See sample-highspeed.c and sample-thread-fast.c for code example.
+
+- Add the following statements to your program source (the define must come
+ _before_ the includes!) :
+
+#define LTT_TRACE
+#define LTT_TRACE_FAST
+#include <ltt/ltt-facility-user_myfacility.h>
+
+- Add a call following the trace_user_myfacility_myevent function found in
+ /usr/include/ltt/ltt-facility-user_myfacility.h in your program.
+For instance :
+trace_user_myfacility_myevent(__FILE__, __func__, __LINE__, 1234, (void*)0xF0F0F0F0);
+
+- Compile your application with at least these parameters to gcc (it is splitted
+ on two lines, joined by a "\") :
+gcc -lltt-usertrace-fast -I /usr/src/usertrace-generic -o myapp myapp.c \
+ /usr/src/usertrace-generic/ltt-facility-loader-user_myfacility.c
+
+It requires a supplementary operation when you take the trace :
+- Start tracing (with lttctl)
+- Start your application
+- Let your application run...
+- Stop tracing
+- Move or copy /tmp/ltt-usertrace info your trace.
+i.e., if your trace is in /tmp/trace1 :
+su
+mv /tmp/ltt-usertrace /tmp/trace1
+
+
+Then, to see only the user_myfacility events :
+lttv -m textDump -t /tmp/trace1 -e "event.facility=user_myfacility"
+
+It will show, for example :
+user_myfacility.myevent: 39507.805584526 (/ltt-usertrace/process-26174.26174.39236180500380_0), 15829, 15736, USER_MODE { "myapp.c", "main", 8, 1234, 0xf0f0f0f0 }
+
+
+
* Fun feature : function instrumentation
Here is how to generate a full trace of you program function calls.
lttv -m textDump -t /tmp/trace1 -e "event.facility=user_generic & (event.name=function_entry & event.name=function_exit)"
It will show, for example :
-user_generic.function_entry: 59329.709939111 (/cpu_0), 19250, 18581, SYSCALL { 0x8048454, 0x80484c2 }
-user_generic.function_exit: 59329.709944613 (/cpu_0), 19250, 18581, SYSCALL { 0x8048454, 0x80484c2 }
+user_generic.function_entry: 59329.709939111 (/ltt-usertrace/process-26202.0.39949996866578_0), 19250, 18581, USER_MODE { 0x8048454, 0x80484c2 }
+user_generic.function_exit: 59329.709944613 (/ltt-usertrace/process-26202.0.39949996866578_0), 19250, 18581, USER_MODE { 0x8048454, 0x80484c2 }
you can then use (from the binutils package)
addr2line -e sample-instrument-fct -i -f 0x8048454
The lookup in LTTV through libbfd has not been implemented yet.
+* Instrumentation of a java program
+
+See the java/ directory of this package. You will have to create a C library
+that holds the tracing functions, following the java-instrument-string.c. It has
+to be called from the Java code as shown in Sample.java.
+
+The generate.sh scripts compiles and executes the Java program with the JNI
+tracing library.
+
projects / lttv.git / blobdiff