diff options
| author |   Chuck Lever <chuck.lever@oracle.com> | 2016-11-29 11:04:50 -0500 |
|---|---|---|
| committer |   J. Bruce Fields <bfields@redhat.com> | 2016-11-30 17:31:13 -0500 |
| commit | e4eb42cecc6dc546aac888ee4913d59121e886ee (patch) | |
| tree | d78a0e21882dfb0ba3046a6f6962285d3efac9ef /net/sunrpc/xprtrdma/svc_rdma_sendto.c | |
| parent | svcrdma: Renovate sendto chunk list parsing (diff) | |
| download | linux-dev-e4eb42cecc6dc546aac888ee4913d59121e886ee.tar.xz linux-dev-e4eb42cecc6dc546aac888ee4913d59121e886ee.zip | |
svcrdma: Remove BH-disabled spin locking in svc_rdma_send()
svcrdma's current SQ accounting algorithm takes sc_lock and disables
bottom-halves while posting all RDMA Read, Write, and Send WRs.
This is relatively heavyweight serialization. And note that Write and
Send are already fully serialized by the xpt_mutex.
Using a single atomic_t should be all that is necessary to guarantee
that ib_post_send() is called only when there is enough space on the
send queue. This is what the other RDMA-enabled storage targets do.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'net/sunrpc/xprtrdma/svc_rdma_sendto.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_sendto.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c index 0a58d4062f2f..30eeab527bd0 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c @@ -594,7 +594,12 @@ int svc_rdma_sendto(struct svc_rqst *rqstp) goto err0; inline_bytes = rqstp->rq_res.len; - /* Create the RDMA response header */ + /* Create the RDMA response header. xprt->xpt_mutex, + * acquired in svc_send(), serializes RPC replies. The + * code path below that inserts the credit grant value + * into each transport header runs only inside this + * critical section. + */ ret = -ENOMEM; res_page = alloc_page(GFP_KERNEL); if (!res_page) |