There is currently a deadlock that commonly occurs when job logging is enabled.

The deadlock occurs because the function mk_job_log_name locks job_log_mutex to
update the time when the log was opened, even though the lock is already take
every time its only caller, job_log_open, is executed. The problem is fixed by
simply removing the lock:

Index: src/lib/Liblog/pbs_log.c
===================================================================
--- src/lib/Liblog/pbs_log.c    (revision 6023)
+++ src/lib/Liblog/pbs_log.c    (working copy)
@@ -272,9 +272,7 @@
             ptm->tm_mday);
     }

-  pthread_mutex_lock(job_log_mutex);
   joblog_open_day = ptm->tm_yday; /* Julian date log opened */
-  pthread_mutex_unlock(job_log_mutex);

   return(pbuf);
   }  /* END mk_job_log_name() */

the structure of the code then matches mk_log_name.