The first locking issue was due to the semaphore I used. I was trying

The first locking issue was due to the semaphore I used.  I was trying
to be overly clever and the context switch when the semaphore was busy
was destroying performance.  Converting to a simple spin lock bough me
a factor of 50 or so.  That said it's still not good enough.  Tests
show bad performance and we are still CPU bound.  The logical fix is
I need to implement per-cpu hot caches to minimize the SMP contention.
Linux and Solaris both have this, I was hoping to do without but it
looks like that's not to be.

   kmem_lock: time (sec)        slabs           objs            hash
   kmem_lock:                   tot/max/calc    tot/max/calc    size/depth
   kmem_lock:  0.022000000      7/6/64  224/177/2048    32768/1
   kmem_lock:  0.039000000      13/13/128       416/404/4096    32768/1
   kmem_lock:  0.079000000      23/21/256       736/672/8192    32768/1
   kmem_lock:  0.158000000      48/47/512       1536/1504/16384 32768/1
   kmem_lock:  0.345000000      105/105/1024    3360/3358/32768 32768/2
   kmem_lock:  0.760000000      202/200/2048    6464/6400/65536 32768/3

git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@135 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c