From: "Michael J. Ruhl" <michael.j.ruhl@intel.com>
Date: Mon, 21 Aug 2017 18:26:45 -0700
Subject: IB/hfi1: Improve local kmem_cache_alloc performance
Patch-mainline: v4.14-rc1
Git-commit: 7956371ea48bd00956219a82fd3af655dd216073
References: bsc#1060463 FATE#323043

Performance analysis shows that the cache callback function
sdma_kmem_cache_ctor contributes to 1/2 of the kmem_cache_allocs
time.

Since all of the fields in the allocated data structure are initialized
in the code path, remove the _ctor function.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hfi1/user_sdma.c   |    9 +--------
 drivers/infiniband/hw/hfi1/verbs_txreq.c |   11 ++---------
 drivers/infiniband/hw/hfi1/vnic_sdma.c   |   13 +++----------
 3 files changed, 6 insertions(+), 27 deletions(-)

--- a/drivers/infiniband/hw/hfi1/user_sdma.c
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -331,13 +331,6 @@ static void activate_packet_queue(struct
 	wake_up(&wait->wait_dma);
 };
 
-static void sdma_kmem_cache_ctor(void *obj)
-{
-	struct user_sdma_txreq *tx = obj;
-
-	memset(tx, 0, sizeof(*tx));
-}
-
 int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
 				struct hfi1_filedata *fd)
 {
@@ -391,7 +384,7 @@ int hfi1_user_sdma_alloc_queues(struct h
 					    sizeof(struct user_sdma_txreq),
 					    L1_CACHE_BYTES,
 					    SLAB_HWCACHE_ALIGN,
-					    sdma_kmem_cache_ctor);
+					    NULL);
 	if (!pq->txreq_cache) {
 		dd_dev_err(dd, "[%u] Failed to allocate TxReq cache\n",
 			   uctxt->ctxt);
--- a/drivers/infiniband/hw/hfi1/verbs_txreq.c
+++ b/drivers/infiniband/hw/hfi1/verbs_txreq.c
@@ -1,5 +1,5 @@
 /*
- * Copyright(c) 2016 Intel Corporation.
+ * Copyright(c) 2016 - 2017 Intel Corporation.
  *
  * This file is provided under a dual BSD/GPLv2 license.  When using or
  * redistributing this file, you may do so under either license.
@@ -119,13 +119,6 @@ out:
 	return tx;
 }
 
-static void verbs_txreq_kmem_cache_ctor(void *obj)
-{
-	struct verbs_txreq *tx = (struct verbs_txreq *)obj;
-
-	memset(tx, 0, sizeof(*tx));
-}
-
 int verbs_txreq_init(struct hfi1_ibdev *dev)
 {
 	char buf[TXREQ_LEN];
@@ -135,7 +128,7 @@ int verbs_txreq_init(struct hfi1_ibdev *
 	dev->verbs_txreq_cache = kmem_cache_create(buf,
 						   sizeof(struct verbs_txreq),
 						   0, SLAB_HWCACHE_ALIGN,
-						   verbs_txreq_kmem_cache_ctor);
+						   NULL);
 	if (!dev->verbs_txreq_cache)
 		return -ENOMEM;
 	return 0;
--- a/drivers/infiniband/hw/hfi1/vnic_sdma.c
+++ b/drivers/infiniband/hw/hfi1/vnic_sdma.c
@@ -303,22 +303,15 @@ void hfi1_vnic_sdma_init(struct hfi1_vni
 	}
 }
 
-static void hfi1_vnic_txreq_kmem_cache_ctor(void *obj)
-{
-	struct vnic_txreq *tx = (struct vnic_txreq *)obj;
-
-	memset(tx, 0, sizeof(*tx));
-}
-
 int hfi1_vnic_txreq_init(struct hfi1_devdata *dd)
 {
 	char buf[HFI1_VNIC_TXREQ_NAME_LEN];
 
 	snprintf(buf, sizeof(buf), "hfi1_%u_vnic_txreq_cache", dd->unit);
 	dd->vnic.txreq_cache = kmem_cache_create(buf,
-					  sizeof(struct vnic_txreq),
-					  0, SLAB_HWCACHE_ALIGN,
-					  hfi1_vnic_txreq_kmem_cache_ctor);
+						 sizeof(struct vnic_txreq),
+						 0, SLAB_HWCACHE_ALIGN,
+						 NULL);
 	if (!dd->vnic.txreq_cache)
 		return -ENOMEM;
 	return 0;