[PATCH 000 of 11] knfsd: Introduction - Make knfsd more NUMA-aware

[NeilBrown <neilb@suse.de>]

Following are 11 patches from Greg Banks which combine to make knfsd
more Numa-aware.  They reduce hitting on 'global' data structures, and
create some data-structures that can be node-local.

knfsd threads are bound to a particular node, and the thread to handle
a new request is chosen from the threads that are attach to the node
that received the interrupt.

The distribution of threads across nodes can be controlled by a new
file in the 'nfsd' filesystem, though the default approach of an even
spread is probably fine for most sites.

Some (old) numbers that show the efficacy of these patches:
N == number of NICs == number of CPUs == nmber of clients.
Number of NUMA nodes == N/2

N	Throughput, MiB/s	CPU usage, % (max=N*100)
	Before	After		Before	After
---	------	----		-----	-----
4	312	435		350	228
6	500	656		501	418
8	562	804		690	589


 [PATCH 001 of 11] knfsd: move tempsock aging to a timer
 [PATCH 002 of 11] knfsd: convert sk_inuse to atomic_t
 [PATCH 003 of 11] knfsd: use new lock for svc_sock deferred list
 [PATCH 004 of 11] knfsd: convert sk_reserved to atomic_t
 [PATCH 005 of 11] knfsd: test and set SK_BUSY atomically
 [PATCH 006 of 11] knfsd: split svc_serv into pools
 [PATCH 007 of 11] knfsd: add svc_get
 [PATCH 008 of 11] knfsd: add svc_set_num_threads
 [PATCH 009 of 11] knfsd: use svc_set_num_threads to manage threads in knfsd
 [PATCH 010 of 11] knfsd: make rpc threads pools numa aware
 [PATCH 011 of 11] knfsd: allow admin to set nthreads per node