Commit 8cec3dba authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker

xprtrdma: rpcrdma_regbuf alignment

Allocate the struct rpcrdma_regbuf separately from the I/O buffer
to better guarantee the alignment of the I/O buffer and eliminate
the wasted space between the rpcrdma_regbuf metadata and the buffer
itself.
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 23146500
......@@ -45,10 +45,10 @@ static int rpcrdma_bc_setup_reqs(struct rpcrdma_xprt *r_xprt,
size = r_xprt->rx_data.inline_rsize;
rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, GFP_KERNEL);
if (IS_ERR(rb))
if (!rb)
goto out_fail;
req->rl_sendbuf = rb;
xdr_buf_init(&rqst->rq_snd_buf, rb->rg_base,
xdr_buf_init(&rqst->rq_snd_buf, rdmab_data(rb),
min_t(size_t, size, PAGE_SIZE));
}
return 0;
......@@ -123,7 +123,7 @@ static int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0);
xdr_init_encode(&req->rl_stream, &req->rl_hdrbuf,
req->rl_rdmabuf->rg_base, rqst);
rdmab_data(req->rl_rdmabuf), rqst);
p = xdr_reserve_space(&req->rl_stream, 28);
if (unlikely(!p))
......
......@@ -747,8 +747,8 @@ rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst)
int ret;
rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0);
xdr_init_encode(xdr, &req->rl_hdrbuf,
req->rl_rdmabuf->rg_base, rqst);
xdr_init_encode(xdr, &req->rl_hdrbuf, rdmab_data(req->rl_rdmabuf),
rqst);
/* Fixed header fields */
ret = -EMSGSIZE;
......
......@@ -595,7 +595,7 @@ rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
return true;
rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
if (IS_ERR(rb))
if (!rb)
return false;
rpcrdma_free_regbuf(req->rl_sendbuf);
......@@ -625,7 +625,7 @@ rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
return true;
rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
if (IS_ERR(rb))
if (!rb)
return false;
rpcrdma_free_regbuf(req->rl_recvbuf);
......@@ -660,8 +660,8 @@ xprt_rdma_allocate(struct rpc_task *task)
if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
goto out_fail;
rqst->rq_buffer = req->rl_sendbuf->rg_base;
rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
rqst->rq_buffer = rdmab_data(req->rl_sendbuf);
rqst->rq_rbuffer = rdmab_data(req->rl_recvbuf);
trace_xprtrdma_op_allocate(task, req);
return 0;
......
......@@ -1013,12 +1013,12 @@ struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, gfp_t flags)
return NULL;
rb = rpcrdma_alloc_regbuf(RPCRDMA_HDRBUF_SIZE, DMA_TO_DEVICE, flags);
if (IS_ERR(rb)) {
if (!rb) {
kfree(req);
return NULL;
}
req->rl_rdmabuf = rb;
xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
xdr_buf_init(&req->rl_hdrbuf, rdmab_data(rb), rdmab_length(rb));
req->rl_buffer = buffer;
INIT_LIST_HEAD(&req->rl_registered);
......@@ -1040,9 +1040,9 @@ static bool rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, bool temp)
rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
DMA_FROM_DEVICE, GFP_KERNEL);
if (IS_ERR(rep->rr_rdmabuf))
if (!rep->rr_rdmabuf)
goto out_free;
xdr_buf_init(&rep->rr_hdrbuf, rep->rr_rdmabuf->rg_base,
xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf),
rdmab_length(rep->rr_rdmabuf));
rep->rr_cqe.done = rpcrdma_wc_receive;
......@@ -1354,8 +1354,7 @@ rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
* @direction: direction of data movement
* @flags: GFP flags
*
* Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
* can be persistently DMA-mapped for I/O.
* Returns a pointer to a rpcrdma_regbuf object, or NULL.
*
* xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
* receiving the payload of RDMA RECV operations. During Long Calls
......@@ -1367,14 +1366,18 @@ rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
{
struct rpcrdma_regbuf *rb;
rb = kmalloc(sizeof(*rb) + size, flags);
if (rb == NULL)
return ERR_PTR(-ENOMEM);
rb = kmalloc(sizeof(*rb), flags);
if (!rb)
return NULL;
rb->rg_data = kmalloc(size, flags);
if (!rb->rg_data) {
kfree(rb);
return NULL;
}
rb->rg_device = NULL;
rb->rg_direction = direction;
rb->rg_iov.length = size;
return rb;
}
......@@ -1392,7 +1395,7 @@ __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
return false;
rb->rg_iov.addr = ib_dma_map_single(device,
(void *)rb->rg_base,
rdmab_data(rb),
rdmab_length(rb),
rb->rg_direction);
if (ib_dma_mapping_error(device, rdmab_addr(rb))) {
......@@ -1427,6 +1430,8 @@ void
rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
{
rpcrdma_dma_unmap_regbuf(rb);
if (rb)
kfree(rb->rg_data);
kfree(rb);
}
......
......@@ -121,33 +121,34 @@ struct rpcrdma_regbuf {
struct ib_sge rg_iov;
struct ib_device *rg_device;
enum dma_data_direction rg_direction;
__be32 rg_base[0] __attribute__ ((aligned(256)));
void *rg_data;
};
static inline u64
rdmab_addr(struct rpcrdma_regbuf *rb)
static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
{
return rb->rg_iov.addr;
}
static inline u32
rdmab_length(struct rpcrdma_regbuf *rb)
static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
{
return rb->rg_iov.length;
}
static inline u32
rdmab_lkey(struct rpcrdma_regbuf *rb)
static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
{
return rb->rg_iov.lkey;
}
static inline struct ib_device *
rdmab_device(struct rpcrdma_regbuf *rb)
static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
{
return rb->rg_device;
}
static inline void *rdmab_data(const struct rpcrdma_regbuf *rb)
{
return rb->rg_data;
}
#define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
/* To ensure a transport can always make forward progress,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment