And the memory usage is rock steady. And that has been true for a long time.
So, what does that tell you?
Your knowledge is out of date. Your platform--be it the pthreads or memory management or whatever--has an underlying problem that cannot be directly addressed by, nor attributed to, Perl. So stop doing that.
So what does that tell me? First, his script gained memory and your's didn't. I observe the same behavior. So a script written 1 way in Perl may leak, and written another may not. Furthermore, these 2 sample thread scripts are the ultimate in simplicity. Leakage problems become more pronounced when you start adding objects to threaded programs.
I have the latest Slackware, and before I believe my slackware c libs are faulty, I have to assume Perl's behavior is somehow causing it.
Since this memory leak problem keeps coming up, all I can do is to mention that thread reuse does prevent the problem.
But you are more of a thread expert than me, so if you insist that perl threads do not have memory problems, and it is the underlying c library's fault, I call that a cop out. If threads have no problems with ref counts and memleaks, why did you post threads: spawn early to avoid the crush.? Or is that information from you already outdated?