Commit 08cf2efd authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Use smaller buffers for RPC-over-RDMA headers 



Commit 94931746 ("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: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 9c40c49f

net/sunrpc/xprtrdma/backchannel.c

+2 −3
Original line number Diff line number Diff line
@@ -45,13 +45,12 @@ static int rpcrdma_bc_setup_rqst(struct rpcrdma_xprt *r_xprt, 
		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;

net/sunrpc/xprtrdma/transport.c

+1 −1
Original line number Diff line number Diff line
@@ -484,7 +484,7 @@ static bool 
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)

net/sunrpc/xprtrdma/xprt_rdma.h

+4 −1
Original line number Diff line number Diff line
@@ -160,7 +160,10 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb) 
 * 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

CRA Git | Maintained and supported by SUSTech CRA and CCSE