SUNRPC: switchable buffer allocation

 Add RPC client transport switch support for replacing buffer management
 on a per-transport basis.

 In the current IPv4 socket transport implementation, RPC buffers are
 allocated as needed for each RPC message that is sent.  Some transport
 implementations may choose to use pre-allocated buffers for encoding,
 sending, receiving, and unmarshalling RPC messages, however.  For
 transports capable of direct data placement, the buffers can be carved
 out of a pre-registered area of memory rather than from a slab cache.

 Test-plan:
 Millions of fsx operations.  Performance characterization with "sio" and
 "iozone".  Use oprofile and other tools to look for significant regression
 in CPU utilization.

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 77e8800d4127..51f07c9a751b 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -28,6 +28,7 @@
 #include <linux/udp.h>
 #include <linux/tcp.h>
 #include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/sched.h>
 #include <linux/file.h>
 
 #include <net/sock.h>
@@ -1161,6 +1162,8 @@ static struct rpc_xprt_ops xs_udp_ops = {
         .reserve_xprt           = xprt_reserve_xprt_cong,
         .release_xprt           = xprt_release_xprt_cong,
         .connect                = xs_connect,
+        .buf_alloc              = rpc_malloc,
+        .buf_free               = rpc_free,
         .send_request           = xs_udp_send_request,
         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
         .timer                  = xs_udp_timer,
@@ -1173,6 +1176,8 @@ static struct rpc_xprt_ops xs_tcp_ops = {
         .reserve_xprt           = xprt_reserve_xprt,
         .release_xprt           = xprt_release_xprt,
         .connect                = xs_connect,
+        .buf_alloc              = rpc_malloc,
+        .buf_free               = rpc_free,
         .send_request           = xs_tcp_send_request,
         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
         .close                  = xs_close,