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

Commit 949317464b ("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>
This commit is contained in:
Chuck Lever 2016-09-15 10:56:02 -04:00 коммит произвёл Anna Schumaker
Родитель 9c40c49f14
Коммит 08cf2efd54
3 изменённых файлов: 7 добавлений и 5 удалений

Просмотреть файл

@ -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;

Просмотреть файл

@ -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)

Просмотреть файл

@ -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