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| author | Chuck Lever <chuck.lever@oracle.com> | 2016-06-29 19:54:49 +0200 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2016-07-11 21:50:43 +0200 |
| commit | cfabe2c634e617765af39ea1cb2920bdcbc5bb7e (patch) | |
| tree | 8be76e009f224a217432ced4bef5151e018bc5f6 /net/sunrpc | |
| parent | xprtrdma: Do not update {head, tail}.iov_len in rpcrdma_inline_fixup() (diff) | |
| download | linux-cfabe2c634e617765af39ea1cb2920bdcbc5bb7e.tar.xz linux-cfabe2c634e617765af39ea1cb2920bdcbc5bb7e.zip | |
xprtrdma: Update only specific fields in private receive buffer
Now that rpcrdma_inline_fixup() updates only two fields in
rq_rcv_buf, a full memcpy of that structure to rq_private_buf is
unwarranted. Updating rq_private_buf fields only where needed also
better documents what is going on.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/xprtrdma/rpc_rdma.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index d018eb7814e7..a0e811dd7b84 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -750,6 +750,11 @@ rpcrdma_count_chunks(struct rpcrdma_rep *rep, int wrchunk, __be32 **iptrp) * The upper layer has set the maximum number of bytes it can * receive in each component of rq_rcv_buf. These values are set in * the head.iov_len, page_len, tail.iov_len, and buflen fields. + * + * Unlike the TCP equivalent (xdr_partial_copy_from_skb), in + * many cases this function simply updates iov_base pointers in + * rq_rcv_buf to point directly to the received reply data, to + * avoid copying reply data. */ static void rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) @@ -763,6 +768,7 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) * in the receive buffer, to avoid a memcopy. */ rqst->rq_rcv_buf.head[0].iov_base = srcp; + rqst->rq_private_buf.head[0].iov_base = srcp; /* The contents of the receive buffer that follow * head.iov_len bytes are copied into the page list. @@ -822,16 +828,15 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) /* The tail iovec is redirected to the remaining data * in the receive buffer, to avoid a memcopy. */ - if (copy_len || pad) + if (copy_len || pad) { rqst->rq_rcv_buf.tail[0].iov_base = srcp; + rqst->rq_private_buf.tail[0].iov_base = srcp; + } if (copy_len) dprintk("RPC: %s: %d bytes in" " %d extra segments (%d lost)\n", __func__, olen, i, copy_len); - - /* TBD avoid a warning from call_decode() */ - rqst->rq_private_buf = rqst->rq_rcv_buf; } void |