Ok, here it is.  This patch works for my simple tests, both under UP and
SMP, including under memory pressure.  I'd appreciate anyone who'd like to
take it and beat on it.  Please let me know of any problems you find.

The patch is against this morning's 2.5 BK tree.

Dave McCracken

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Dave McCracken          IBM Linux Base Kernel Team      1-512-838-3059
dmccr@us.ibm.com                                        T/L   678-3059