[net-next][PATCH v2 2/2] rds: add sysctl for rds support of On-Demand-Paging

[Santosh Shilimkar]

RDS doesn't support RDMA on memory apertures that require On Demand
Paging (ODP), such as FS DAX memory. A sysctl is added to indicate
whether RDMA requiring ODP is supported.

Reviewed-by: Håkon Bugge <haakon.bu...@oracle.com>
Reviewed-tested-by: Zhu Yanjun <yanjun....@oracle.com>
Signed-off-by: Hans Westgaard Ry <hans.westgaard...@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilim...@oracle.com>
---
 net/rds/ib.h        | 1 +
 net/rds/ib_sysctl.c | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/net/rds/ib.h b/net/rds/ib.h
index 67a715b..80e11ef 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -457,5 +457,6 @@ unsigned int rds_ib_stats_info_copy(struct 
rds_info_iterator *iter,
 extern unsigned long rds_ib_sysctl_max_unsig_bytes;
 extern unsigned long rds_ib_sysctl_max_recv_allocation;
 extern unsigned int rds_ib_sysctl_flow_control;
+extern unsigned int rds_ib_sysctl_odp_support;
 
 #endif
diff --git a/net/rds/ib_sysctl.c b/net/rds/ib_sysctl.c
index e4e41b3..7cc02cd 100644
--- a/net/rds/ib_sysctl.c
+++ b/net/rds/ib_sysctl.c
@@ -60,6 +60,7 @@
  * will cause credits to be added before protocol negotiation.
  */
 unsigned int rds_ib_sysctl_flow_control = 0;
+unsigned int rds_ib_sysctl_odp_support;
 
 static struct ctl_table rds_ib_sysctl_table[] = {
        {
@@ -103,6 +104,13 @@
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
+       {
+               .procname       = "odp_support",
+               .data           = &rds_ib_sysctl_odp_support,
+               .maxlen         = sizeof(rds_ib_sysctl_odp_support),
+               .mode           = 0444,
+               .proc_handler   = proc_dointvec,
+       },
        { }
 };
 
-- 
1.9.1