Avoid using nfsd process pools on SMP machines.

process-pools have real benefits for NUMA, but on SMP
machines they only work if network interface interrupts
go to all CPUs (via round-robin or multiple nics).  This is
not always the case, so disable the pools in this case until
a better solution is developped.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff .prev/net/sunrpc/svc.c ./net/sunrpc/svc.c

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index c1f878131ac61b6f9f24d1516e5ad00320526f9b..39fada1cee4e46290996d48c87963f4342902bd3 100644 (file)
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -79,7 +79,11 @@ svc_pool_map_choose_mode(void)
                 * x86_64 kernel on Xeons.  In this case we
                 * want to divide the pools on cpu boundaries.
                 */
-               return SVC_POOL_PERCPU;
+               /* actually, unless your IRQs round-robin nicely,
+                * this turns out to be really bad, so just
+                * go GLOBAL for now until a better fix can be developped
+                */
+               return SVC_POOL_GLOBAL;
        }
 
        /* default: one global pool */