On Wed, 1 Jul 2026 11:04:07 +0100 David Laight <[email protected]> wrote:
> > I thought it was just used to do a pid->string lookup when you run 'cat > trace'. > But then I found the code that lets userspace read the table.... > I guess the latter is used by the userspace code that reads the raw trace > buffer. Yes, trace-cmd uses it. > (I found some instructions that did it that way, the output was unparseable > when tracing things that are happening on multiple cpu.) > The userspace code could probably be given comm[] for all the running > processes and those that exited while tracing_on() set. > (I didn't see anything that would clear the table when the trace buffer > was cleared.) Well, that would break trace-cmd. As reading the raw buffers clears the trace, and trace-cmd reads the saved_cmdlines file *after* it reads the trace, as during the trace it gets populated. -- Steve
