Coalescing pipe allocation

[Dag-ErlingSmørgrav]

Robert Watson <rwatson at FreeBSD.org> writes:
> FYI, the vast majority of the cost of pipe creation appears to be in
> setting up those mappings.  I ran some mutex profiling and the amount of
> work getting done is pretty high -- we should be able to reap a lot of
> benefit by doing even a little less work there.

Like I said, setting up a VM mapping is very inefficient in FreeBSD.
This, and the fd allocation issue which I fixed earlier this year,
were the two areas where fefe's scalability benchmark really trounced
us last October.

DES
-- 
Dag-Erling Smørgrav - des at des.no