[PTLsim-devel] Subtract option in ptlstats does not work

Mon Jan 21 20:56:10 EST 2008

Hi,

I have been working with a project in PTLsim/X for a couple of months 
and I am having trouble with the -subtract option in PTLstats. I'll 
start off with explaining what I've been doing.

In PTLsim/X I have been running a bash-script that executes a number of 
benchmarks one after the other in the same domain, switching statfile in 
between the benchmarks. Before each benchmark, just after creating a new 
statfile, an initial snapshot have been taken. I want to subtract this 
snapshot from the final snapshot in order to get the actual statistics 
for each benchmark.

I create a new statfile by
echo "-stats $statfilename -native" >> /proc/xen/ptlcall

And a new snapshot by
echo "-snapshot-now startpoint -native" >> /proc/xen/ptlcall

This works fine as far as I can tell. I get my stat files, one for each 
benchmark and with two entries in each stat file (by -info option). 
Also, I can see the two different snapshots by giving the -snapshot 
option to ptlstats, and they are correct.

    ~$ /ptlsim/bin/ptlstats -info j9.full._213_javac.stats  
    Data store header version 'PTLdst01'
      Template at:                64,            70521 bytes
      Records at:              73728,            28504 bytes
      Index at:               130736,                2 entries
      Record count:                2 records

    Index:
    Hashtable of 256 sets containing 2 entries:
      startpoint -> 0
      final -> 1

Now to my problem:

I can't get the -subtract option to work. I have tried it in all 
possible ways, no matter what it just gives me the final snapshot 
without subtracting anaything.

What I want to do is the following (according to the PTLsim reference 
manual)

    /ptlsim/bin/ptlstats -snapshot final -subtract startpoint /statfilename
/
but it just gives me the final snapshot. I have also tried by giving the 
snapshots as 1 and 0 respectively, that gives me the same result.

The following demonstrates that there is no difference between the 
resulting output:
~$ /ptlsim/bin/ptlstats -snapshot final -subtract startpoint 
j9.full._213_javac.stats >         subtract.txt
~$ /ptlsim/bin/ptlstats -snapshot final j9.full._213_javac.stats > 
nosubtract.txt
~$ diff subtract.txt nosubtract.txt
~$  

Am I doing something wrong? Have anyone else experienced the same problem?

Regards,
Magnus Gustafsson
Dept. of Computer Science
The Australian National University