[PATCH] knfsd: provide sunrpc pool_mode module option
Provide a module param "pool_mode" for sunrpc.ko which allows a sysadmin to
choose the mode for mapping NFS thread service pools to CPUs. Values are:
auto choose a mapping mode heuristically
global (default, same as the pre-2.6.19 code) a single global pool
percpu one pool per CPU
pernode one pool per NUMA node
Note that since 2.6.19 the hardcoded behaviour has been "auto", this patch
makes the default "global".
The pool mode can be changed after boot/modprobe using /sys, if the NFS and
lockd services have been shut down. A useful side effect of this change is to
fix a small memory leak when unloading the module.
Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 03eb5ed..6e92ba6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1685,6 +1685,22 @@
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
+ sunrpc.pool_mode=
+ [NFS]
+ Control how the NFS server code allocates CPUs to
+ service thread pools. Depending on how many NICs
+ you have and where their interrupts are bound, this
+ option will affect which CPUs will do NFS serving.
+ Note: this parameter cannot be changed while the
+ NFS server is running.
+
+ auto the server chooses an appropriate mode
+ automatically using heuristics
+ global a single global pool contains all CPUs
+ percpu one pool for each CPU
+ pernode one pool for each NUMA node (equivalent
+ to global on non-NUMA machines)
+
swiotlb= [IA-64] Number of I/O TLB slabs
switches= [HW,M68k]