And the other:
19720 pts/2S 0:04 postgres: award Trucking [local] UPDATE
(gdb) bt
#0 0x4021cec6 in sigsuspend () from /lib/libc.so.6
#1 0x424b6218 in __pthread_wait_for_restart_signal ()
from /lib/libpthread.so.0
#2 0x424b79a0 in __pthread_alt_lock () from /lib/libpthread.so
It's really too bad that your gdb backtrace didn't show anything past
the write_syslog level (which is an elog subroutine). If we could see
whether the elog had been issued from a signal handler, and if so what
it had interrupted, we'd have an idea whether this is a known syslog
deficiency
