xprtrdma: Use smaller buffers for RPC-over-RDMA headers
Commit 949317464bc2 ("xprtrdma: Limit number of RDMA segments in
RPC-over-RDMA headers") capped the number of chunks that may appear
in RPC-over-RDMA headers. The maximum header size can be estimated
and fixed to avoid allocating buffer space that is never used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index c4904f8..60fc991 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -45,13 +45,12 @@
return PTR_ERR(req);
req->rl_backchannel = true;
- size = r_xprt->rx_data.inline_wsize;
- rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL);
+ rb = rpcrdma_alloc_regbuf(ia, RPCRDMA_HDRBUF_SIZE, GFP_KERNEL);
if (IS_ERR(rb))
goto out_fail;
req->rl_rdmabuf = rb;
- size += r_xprt->rx_data.inline_rsize;
+ size = r_xprt->rx_data.inline_rsize;
rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL);
if (IS_ERR(rb))
goto out_fail;
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index ecdc3ad..94dbfd3 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -484,7 +484,7 @@
rpcrdma_get_rdmabuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
gfp_t flags)
{
- size_t size = r_xprt->rx_data.inline_wsize;
+ size_t size = RPCRDMA_HDRBUF_SIZE;
struct rpcrdma_regbuf *rb;
if (req->rl_rdmabuf)
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 444f637..cc426b1 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -160,7 +160,10 @@
* The smallest inline threshold is 1024 bytes, ensuring that
* at least 750 bytes are available for RPC messages.
*/
-#define RPCRDMA_MAX_HDR_SEGS (8)
+enum {
+ RPCRDMA_MAX_HDR_SEGS = 8,
+ RPCRDMA_HDRBUF_SIZE = 256,
+};
/*
* struct rpcrdma_rep -- this structure encapsulates state required to recv