I have a process which several times now has stopped responding and appears to be completely locking up. It doesn't respond to any attempt at strace or peeking with gdb (gdb just hangs on a wait4() syscall). The process is runnable, and is not waiting on a syscall (/proc/X/syscall:
running) or in uninterruptable sleep (/proc/X/status:
State: R (running)).
What state is this process in exactly? Is this possibly a kernel bug of some type?
The process is redis, and this has happened a few times now. Only thing that can kill the process is a reboot, it seems. OS is Cent 7.
Edit: Kernel version is 3.10.0-123.13.2.el7.x86_64. Trying an update to 3.10.0-229.11.1.el7 to see if that makes any difference.