I have a big, long running task on a SLES 12 server. I just tried using
gstack on it, but the gstack processes don't seem to be getting any CPU - nothing on the screen after over 20 minutes. The machine doesn't seem to be particularly loaded (32 CPUs load of 2.4; 1TB RAM, 100G free). The process itself in top seems idle most of the time, with occasional bursts at around 200% CPU.
Any suggestions as to what is going on?