Identify what child threads/PIDs are doing
 

We have Novell's zLinux running on our mainframe IFL LPAR. We have installed WebSphere and have some performance issues as compared to its Windows counterpart. I start a linux STRACE on the WebSphere PID and ask for child process activity.
Viewing the STRACE output file there are many child processes initiated during the execution of one WebSphere Application transaction. BTW, there is only one WebSphere transaction running at a time to keep the STRACE output file from being clutered with other stuff.
Is tere a way to find out what process each child process is executing?
Some are obvious such as GETTIMEOFDAY, etc. There are others which have some response times longer than others. Those are the ones we are interested in.
Help from anyone will be greatly appreciated.
Thanks
Joe

One of the better sources of performance data is the sar data collector. If you run that every ten minutes then you can use the sar utility to create reports showing all sorts of performance characteristics. It certainly can be used to find processes that are performing poorly along with the command(s) that they are running. The sar utility can be used interactively or it can be run automatically to create reports based on the data collected by the sar data collector.

We have used that process.
When WebSphere is processing a transaction it initiates many sub processesor child PIDs. These are not seen with SAR or the PS command. They will show up when using STRACE -f. Some of these child processes have futex, FUTEX_WAIT, FUTEX_WAKE, SYS_7, SYS_195, etc in the trace output. We are trying to determine is any of these systems call could be causing our performance problems.
Joe