Running Timer Code

From Earlham CS Department
Revision as of 19:19, 23 October 2005 by Lemanal (talk | contribs)
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Basic Flow:

  1. make sure the tp_timer module is installed and working on the client and server nodes
  2. clear /proc/tp_timer on both client and server machines (just read its contents; cat /proc/tp_timer > /dev/null)
  3. run pacgen on client and server to amass new data.
  4. read data into log files on both server and client
  5. load data from the log files into database
  6. look at data via php scripts


Machines setup with llk timing: b10,b11,c10,c11

Need to check out from CVS:

  • llk-pacgen - cvs module with modified pacgen


To compile the kernel copy in a .config file from the ccg-configs cvs. Make sure that CONFIG_TP_TIMER=y (for tp_timer built in) or CONFIG_TP_TIMER=m (for a module version of tp_timer). And, checkout llk-sources. Note that there is a significant chance that this compilation will crash the machine running tp_timer (having the module unloaded is OK). This is probably a problem with NFS so building it locally may work. Otherwise, you may not want to compile the module on the machine you want to test with. Next, use standard machine dependent kernel build and install instructions: make; make modules_install Copy the results of this to the target machine if it is not the local machine. Update, grub or yaboot and reboot. If you have loaded it as a module you must modprobe tp_timer after boot in order to install the module. The first some number of packets from pacgen will be used to calibrate the timers. They should not be used for data.

pacgen sample commands:

./server tcp <port number>
./client -t <protocol> -s <source IP> -m <source port> -d <dest IP> -p <dest port>

Each window is a specific ID for the packet. This ID is used as the payload for the packets. Useful for checking for packet fragmentation (educated guess via Alex). Windows are 0xffffffff, 0xffffffff (2 unsigned ints worth of 1's), an unsigned int for socket/thread id (We don't use it; that part of the code was removed), and an unsigned int holding the window number (we don't know what this is for).

After pacgen is ran with on a tp timer enabled machine, the timing results will be available in /proc/tp_timer. Note that after you read this proc entry, the information will be cleared.


To enter the data into our database:

  1. Collect the /proc/tp_timer from the server node and the client node:
    1. cat /proc/tp_timer > tp_timer_client.log
  2. Execute the create-table-llk.pl script found in the the llk cvs module in the scripts sub directory.
    1. Usage: ./create-table-llk.pl <tablename> <label> <datafile> <client|server>
    2. If the table given by name to the scripts doesn't exist, the script creates the table.