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authorChuck Lever <chuck.lever@oracle.com>2017-02-08 17:00:10 -0500
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2017-02-10 14:02:36 -0500
commit16f906d66cd76fb9895cbc628f447532a7ac1faa (patch)
treec43d002d1c1922281c3adf440282b4944814d0ac /net/sunrpc/xprtrdma/xprt_rdma.h
parentxprtrdma: Disable pad optimization by default (diff)
downloadlinux-dev-16f906d66cd76fb9895cbc628f447532a7ac1faa.tar.xz
linux-dev-16f906d66cd76fb9895cbc628f447532a7ac1faa.zip
xprtrdma: Reduce required number of send SGEs
The MAX_SEND_SGES check introduced in commit 655fec6987be ("xprtrdma: Use gathered Send for large inline messages") fails for devices that have a small max_sge. Instead of checking for a large fixed maximum number of SGEs, check for a minimum small number. RPC-over-RDMA will switch to using a Read chunk if an xdr_buf has more pages than can fit in the device's max_sge limit. This is considerably better than failing all together to mount the server. This fix supports devices that have as few as three send SGEs available. Reported-by: Selvin Xavier <selvin.xavier@broadcom.com> Reported-by: Devesh Sharma <devesh.sharma@broadcom.com> Reported-by: Honggang Li <honli@redhat.com> Reported-by: Ram Amrani <Ram.Amrani@cavium.com> Fixes: 655fec6987be ("xprtrdma: Use gathered Send for large ...") Cc: stable@vger.kernel.org # v4.9+ Tested-by: Honggang Li <honli@redhat.com> Tested-by: Ram Amrani <Ram.Amrani@cavium.com> Tested-by: Steve Wise <swise@opengridcomputing.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xprtrdma/xprt_rdma.h')
-rw-r--r--net/sunrpc/xprtrdma/xprt_rdma.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index c13715431419..3d7e9c9bad1f 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -74,6 +74,7 @@ struct rpcrdma_ia {
unsigned int ri_max_frmr_depth;
unsigned int ri_max_inline_write;
unsigned int ri_max_inline_read;
+ unsigned int ri_max_send_sges;
bool ri_reminv_expected;
bool ri_implicit_roundup;
enum ib_mr_type ri_mrtype;
@@ -311,6 +312,7 @@ struct rpcrdma_mr_seg { /* chunk descriptors */
* - xdr_buf tail iovec
*/
enum {
+ RPCRDMA_MIN_SEND_SGES = 3,
RPCRDMA_MAX_SEND_PAGES = PAGE_SIZE + RPCRDMA_MAX_INLINE - 1,
RPCRDMA_MAX_PAGE_SGES = (RPCRDMA_MAX_SEND_PAGES >> PAGE_SHIFT) + 1,
RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,