PROBLEM: (QAR 57576) (Patch ID: OSF405-370) ******** A process may hang while attempting to obtain a file lock using flock() when run on an SMP system. A dbx stack trace on a running system would look similar to the following: 0 thread_block() ["../../../../src/kernel/kern/sched_prim.c":1865] 1 mpsleep() ["../../../../src/kernel/bsd/kern_synch.c":434 ] 2 vn_flock() ["../../../../src/kernel/vfs/vfs_vnops.c":1313] 3 flock() ["../../../../src/kernel/bsd/kern_descrip.c":1447] 4 syscall() ["../../../../src/kernel/arch/alpha/syscall_trap.c":515] 5 _Xsyscall() ["../../../../src/kernel/arch/alpha/locore.s":1093] The hung process can be interrupted with Control/C or any other kill SIGNAL. This situation can occur if multiple processes are locking and unlocking the same file using the flock() system call on an SMP system. This problem will not occur on a single CPU system.