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authorChuck Lever <chuck.lever@oracle.com>2016-01-07 14:50:02 -0500
committerDoug Ledford <dledford@redhat.com>2016-01-19 15:30:48 -0500
commit03fe9931536fe4782e9e34f7f499d588acd2015b (patch)
treecfee0f65e50640e7daf02eff73e9748a2e1d8db5 /include/linux
parentba986c96f907a513215fb7f1c0a89261c97251ca (diff)
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svcrdma: Define maximum number of backchannel requests
Extra resources for handling backchannel requests have to be pre-allocated when a transport instance is created. Set up additional fields in svcxprt_rdma to track these resources. The max_requests fields are elements of the RPC-over-RDMA protocol, so they should be u32. To ensure that unsigned arithmetic is used everywhere, some other fields in the svcxprt_rdma struct are updated. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Bruce Fields <bfields@fieldses.org> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/sunrpc/svc_rdma.h13
1 files changed, 10 insertions, 3 deletions
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index aeffa30655ce..9a2c418dc690 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -51,6 +51,7 @@
/* RPC/RDMA parameters and stats */
extern unsigned int svcrdma_ord;
extern unsigned int svcrdma_max_requests;
+extern unsigned int svcrdma_max_bc_requests;
extern unsigned int svcrdma_max_req_size;
extern atomic_t rdma_stat_recv;
@@ -134,10 +135,11 @@ struct svcxprt_rdma {
int sc_max_sge;
int sc_max_sge_rd; /* max sge for read target */
- int sc_sq_depth; /* Depth of SQ */
atomic_t sc_sq_count; /* Number of SQ WR on queue */
-
- int sc_max_requests; /* Depth of RQ */
+ unsigned int sc_sq_depth; /* Depth of SQ */
+ unsigned int sc_rq_depth; /* Depth of RQ */
+ u32 sc_max_requests; /* Forward credits */
+ u32 sc_max_bc_requests;/* Backward credits */
int sc_max_req_size; /* Size of each RQ WR buf */
struct ib_pd *sc_pd;
@@ -186,6 +188,11 @@ struct svcxprt_rdma {
#define RPCRDMA_MAX_REQUESTS 32
#define RPCRDMA_MAX_REQ_SIZE 4096
+/* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
+ * current NFSv4.1 implementation supports one backchannel slot.
+ */
+#define RPCRDMA_MAX_BC_REQUESTS 2
+
#define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD
/* svc_rdma_marshal.c */