2008-08-13 16:13:23

by Tom Tucker

[permalink] [raw]
Subject: [PATCH,RFC 06/09] svcrdma: Add support to svc_rdma_send to handle chained WR


WR can be submitted as linked lists of WR. Update the svc_rdma_send
routine to handle WR chains. This will be used to submit a WR that
uses an FRMR with another WR that invalidates the FRMR.

Signed-off-by: Tom Tucker <[email protected]>

---
net/sunrpc/xprtrdma/svc_rdma_transport.c | 29
+++++++++++++++++++++--------
1 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c
b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index a61caa7..1f561c0 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -1252,17 +1252,23 @@ int svc_rdma_fastreg(struct svcxprt_rdma *xprt,

int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr)
{
- struct ib_send_wr *bad_wr;
+ struct ib_send_wr *bad_wr, *n_wr;
+ int wr_count;
+ int i;
int ret;

if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags))
return -ENOTCONN;

BUG_ON(wr->send_flags != IB_SEND_SIGNALED);
+ wr_count = 1;
+ for (n_wr = wr->next; n_wr; n_wr = n_wr->next)
+ wr_count++;
+
/* If the SQ is full, wait until an SQ entry is available */
while (1) {
spin_lock_bh(&xprt->sc_lock);
- if (xprt->sc_sq_depth == atomic_read(&xprt->sc_sq_count)) {
+ if (xprt->sc_sq_depth < atomic_read(&xprt->sc_sq_count) + wr_count) {
spin_unlock_bh(&xprt->sc_lock);
atomic_inc(&rdma_stat_sq_starve);

@@ -1277,19 +1283,26 @@ int svc_rdma_send(struct svcxprt_rdma *xprt,
struct ib_send_wr *wr)
return 0;
continue;
}
- /* Bumped used SQ WR count and post */
- svc_xprt_get(&xprt->sc_xprt);
+ /* Take a transport ref for each WR posted */
+ for (i = 0; i < wr_count; i++)
+ svc_xprt_get(&xprt->sc_xprt);
+
+ /* Bump used SQ WR count and post */
+ atomic_add(wr_count, &xprt->sc_sq_count);
ret = ib_post_send(xprt->sc_qp, wr, &bad_wr);
- if (!ret)
- atomic_inc(&xprt->sc_sq_count);
- else {
- svc_xprt_put(&xprt->sc_xprt);
+ if (ret) {
+ set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+ atomic_sub(wr_count, &xprt->sc_sq_count);
+ for (i = 0; i < wr_count; i ++)
+ svc_xprt_put(&xprt->sc_xprt);
dprintk("svcrdma: failed to post SQ WR rc=%d, "
"sc_sq_count=%d, sc_sq_depth=%d\n",
ret, atomic_read(&xprt->sc_sq_count),
xprt->sc_sq_depth);
}
spin_unlock_bh(&xprt->sc_lock);
+ if (ret)
+ wake_up(&xprt->sc_send_wait);
break;
}
return ret;