6420234 ddi_umem_unlock doesn't unlock immediately

[eiji....@sun.com]

Author: eota
Repository: /hg/onnv/onnv-gate
Revision: a9583664dd7014e32f7ddca1ed8ba0a012eb6690
Log message:
6420234 ddi_umem_unlock doesn't unlock immediately

Files:
        update: usr/src/uts/common/os/sunddi.c