xprtrdma: Add a "max_payload" op for each memreg mode
The max_payload computation is generalized to ensure that the
payload maximum is the lesser of RPC_MAX_DATA_SEGS and the number of
data segments that can be transmitted in an inline buffer.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Devesh Sharma <Devesh.Sharma@Emulex.Com>
Tested-by: Meghana Cheripady <Meghana.Cheripady@Emulex.Com>
Tested-by: Veeresh U. Kokatnur <veereshuk@chelsio.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index c3319e1..da55cda 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -2212,43 +2212,24 @@
return rc;
}
-/* Physical mapping means one Read/Write list entry per-page.
- * All list entries must fit within an inline buffer
- *
- * NB: The server must return a Write list for NFS READ,
- * which has the same constraint. Factor in the inline
- * rsize as well.
+/* How many chunk list items fit within our inline buffers?
*/
-static size_t
-rpcrdma_physical_max_payload(struct rpcrdma_xprt *r_xprt)
+unsigned int
+rpcrdma_max_segments(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
- unsigned int inline_size, pages;
+ int bytes, segments;
- inline_size = min_t(unsigned int,
- cdata->inline_wsize, cdata->inline_rsize);
- inline_size -= RPCRDMA_HDRLEN_MIN;
- pages = inline_size / sizeof(struct rpcrdma_segment);
- return pages << PAGE_SHIFT;
-}
-
-static size_t
-rpcrdma_mr_max_payload(struct rpcrdma_xprt *r_xprt)
-{
- return RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT;
-}
-
-size_t
-rpcrdma_max_payload(struct rpcrdma_xprt *r_xprt)
-{
- size_t result;
-
- switch (r_xprt->rx_ia.ri_memreg_strategy) {
- case RPCRDMA_ALLPHYSICAL:
- result = rpcrdma_physical_max_payload(r_xprt);
- break;
- default:
- result = rpcrdma_mr_max_payload(r_xprt);
+ bytes = min_t(unsigned int, cdata->inline_wsize, cdata->inline_rsize);
+ bytes -= RPCRDMA_HDRLEN_MIN;
+ if (bytes < sizeof(struct rpcrdma_segment) * 2) {
+ pr_warn("RPC: %s: inline threshold too small\n",
+ __func__);
+ return 0;
}
- return result;
+
+ segments = 1 << (fls(bytes / sizeof(struct rpcrdma_segment)) - 1);
+ dprintk("RPC: %s: max chunk list size = %d segments\n",
+ __func__, segments);
+ return segments;
}