On Sat, Feb 26, 2022 at 02:07:05PM -0500, Tom Lane wrote: > I don't know much about how gdb interacts with kernel calls on > FreeBSD, but I speculate that the poll(2) call returns with EINTR > after gdb releases the process, and then things resume fine, > suggesting that we lost an interrupt somewhere.
I've seen some similar interactions with strace under linux causing a process to be woken up or otherwise incur a different behavior (not necessarily postgres). > Thoughts? Ideas on debugging this? Before attaching a debugger, figure out what syscall each process is in. In linux, that's ps O wchan PID. >> Besides trying to make the issue more likely as suggested above, it might be >> worth checking if signalling the stuck processes with SIGUSR1 gets them >> unstuck. And SIGCONT. Maybe already did this, but you can dump a corefile of the running processes to allow future inspection. -- Justin
