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authorChuck Lever <chuck.lever@oracle.com>2016-09-15 10:55:37 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2016-09-19 13:08:37 -0400
commit68778945e46f143ed7974b427a8065f69a4ce944 (patch)
treea513ebe3eb2dd881a67bd55a3a0aa3d525eb4463 /net
parent3435c74aed2d7b743ccbf34616c523ebee7be943 (diff)
downloadlinux-68778945e46f143ed7974b427a8065f69a4ce944.tar.bz2
SUNRPC: Separate buffer pointers for RPC Call and Reply messages
For xprtrdma, the RPC Call and Reply buffers are involved in real I/O operations. To start with, the DMA direction of the I/O for a Call is opposite that of a Reply. In the current arrangement, the Reply buffer address is on a four-byte alignment just past the call buffer. Would be friendlier on some platforms if that was at a DMA cache alignment instead. Because the current arrangement allocates a single memory region which contains both buffers, the RPC Reply buffer often contains a page boundary in it when the Call buffer is large enough (which is frequent). It would be a little nicer for setting up DMA operations (and possible registration of the Reply buffer) if the two buffers were separated, well-aligned, and contained as few page boundaries as possible. Now, I could just pad out the single memory region used for the pair of buffers. But frequently that would mean a lot of unused space to ensure the Reply buffer did not have a page boundary. Add a separate pointer to rpc_rqst that points right to the RPC Reply buffer. This makes no difference to xprtsock, but it will help xprtrdma in subsequent patches. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net')
-rw-r--r--net/sunrpc/clnt.c2
-rw-r--r--net/sunrpc/sched.c1
-rw-r--r--net/sunrpc/xprtrdma/transport.c1
3 files changed, 3 insertions, 1 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 5499fda0c1f3..34dd7b26ee5f 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1766,7 +1766,7 @@ rpc_xdr_encode(struct rpc_task *task)
req->rq_buffer,
req->rq_callsize);
xdr_buf_init(&req->rq_rcv_buf,
- (char *)req->rq_buffer + req->rq_callsize,
+ req->rq_rbuffer,
req->rq_rcvsize);
p = rpc_encode_header(task);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 6690ebc774ed..5db68b371db2 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -891,6 +891,7 @@ int rpc_malloc(struct rpc_task *task)
dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
task->tk_pid, size, buf);
rqst->rq_buffer = buf->data;
+ rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
return 0;
}
EXPORT_SYMBOL_GPL(rpc_malloc);
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index ebf14ba437c6..136caf3dd299 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -524,6 +524,7 @@ out:
dprintk("RPC: %s: size %zd, request 0x%p\n", __func__, size, req);
req->rl_connect_cookie = 0; /* our reserved value */
rqst->rq_buffer = req->rl_sendbuf->rg_base;
+ rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_rcvsize;
return 0;
out_rdmabuf: