rx-2tier-freepacketq-20050403

rx-2tier-freepacketq-20050403

FIXES 17805

The attached patch turns the rx free packet queue into a 2-tiered cache
with a local thread-specific queue, backed by a global queue when using
pthreaded rx. The patch is against 1.3.79. Preliminary benchmarks show
scalability much closer to 2 cpus on sparc with this patch. Also,
fileserver performance under heavy load is improved: 50% improvement in
throughput for sequential writes, and a 10% improvement in performance for
random writes against an smp sparc solaris 10 fileserver.