A graph is usually associated with some nice graphical presentation.
Yet The VTune? for Linux (Command Line) has no
graphical utilities to show the call graph.
On first glance, that might seem like a definite
missing feature. But it might not be.
In this small article I?ll try to convince you that
text representation for call graph is powerful
enough to get quick and meaningful results.



Use scripts to collect data

The great news for The VTune? for Linux (Command Line)
is ? Command Line Interface. Actually that means one
can script everything. You may create different
activities that check different program paths in your
application. Run these activities, get the results and
save them in files. All these operations can be performed
in one simple script, which will run unattainable.

Look at this example.

#!/bin/csh mkdir results set name=MyAppPath1 # create and run an activity ?MyAppPath1? that runs # /home/user/myapp ?path1 # in the /home/user/mywork directory vtl activity $name -c callgraph -app /home/user/myapp,-path1,/home/user/mywork ?moi /home/user/myapp run #print the list of all functions with collected data vtl view ?functions >! results/${name}_func.csv #list functions in the critical path vtl view -critical-path >! results/${name}_cp.csv #print out the list of each function and it?s callees vtl view -calls >! results/${name}_calls.csv #run your application with other flags(e.g. with ?path2) set name=MyAppPath2 vtl activity $name -c callgraph -app /home/user/myapp,-path2,/home/user/mywork ?moi /home/user/myapp run vtl view ?functions >! results/${name}_func.csv vtl view -critical-path >! results/${name}_cp.csv vtl view -calls >! results/${name}_calls.csv #etc

TIP: Use excessive output. Vtl application has
numerous switches to give the user the exact information
he/she requires. E.g. it is possible to get the
information about one specific function.
But I recommend using the excessive approach,
i.e. to get all available info about all functions or
calls (use flags ?functions/-calls).
Dump this information to file and later on filter
for specific function(s).




Analyzing the results

Now use all your Linux favorite commands and applications
like ?tail?, ?awk?, ?perl? etc. to get the most of the
data dumped in file. The output files are tables, with
semi column used. The number of the column is printed in
it?s header. Here are some examples :

# get top 10 functions with biggest ?Total Time?, which is the 6-th column sort -k 6 -n -t; -r MyAppPath1_func.csv | head -10 | less ?S # top 10 functions with biggest ?Self Time?, which is the 5-th column in library #?libc? grep libc MyAppPath1_func.csv | sort -k 6 -n -t; -r | head -10 | less ?S #print only 2 columns: function name and number of calls awk -F; '{print $1 $9}' MyAppPath1_func.csv

Comparing results

After doing some changes in your code, run the collection
a second time and dump result to files again. I attach a
small ?perl? script ?cmp? which compares 2 files with
function lists and prints out the functions with number
changes,
To use this script, supply 2 files and the column number, like:

cmp ftabl1(reference) ftabl2 col_num

Enjoy the text surfing of the cal
l graph!