From: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Increasing the default MTU size to 10KB improves performance
for PSM. Change the default MTU to 10KB but constrain
Verbs MTU to 8KB.
Reviewed-by: Dean Luick <dean.luick@xxxxxxxxx>
Reviewed-by: Mitko Haralanov <mitko.haralanov@xxxxxxxxx>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/hfi.h | 4 ++--
drivers/infiniband/hw/hfi1/qp.c | 6 +++++-
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index ac553f1..ff04593 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -455,9 +455,9 @@ struct rvt_sge_state;
#define HLS_UP (HLS_UP_INIT | HLS_UP_ARMED | HLS_UP_ACTIVE)
/* use this MTU size if none other is given */
-#define HFI1_DEFAULT_ACTIVE_MTU 8192
+#define HFI1_DEFAULT_ACTIVE_MTU 10240
/* use this MTU size as the default maximum */
-#define HFI1_DEFAULT_MAX_MTU 8192
+#define HFI1_DEFAULT_MAX_MTU 10240
/* default partition key */
#define DEFAULT_PKEY 0xffff
diff --git a/drivers/infiniband/hw/hfi1/qp.c b/drivers/infiniband/hw/hfi1/qp.c
index 29a5ad2..e68d08a 100644
--- a/drivers/infiniband/hw/hfi1/qp.c
+++ b/drivers/infiniband/hw/hfi1/qp.c
@@ -167,8 +167,12 @@ static inline int opa_mtu_enum_to_int(int mtu)
*/
static inline int verbs_mtu_enum_to_int(struct ib_device *dev, enum ib_mtu mtu)
{
- int val = opa_mtu_enum_to_int((int)mtu);
+ int val;
+ /* Constraining 10KB packets to 8KB packets */
+ if (mtu == (enum ib_mtu)OPA_MTU_10240)
+ mtu = OPA_MTU_8192;
+ val = opa_mtu_enum_to_int((int)mtu);
if (val > 0)
return val;
return ib_mtu_enum_to_int(mtu);
--
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