From: Maor Gottlieb <maorg@mellanox.com>
Date: Sun, 21 Jun 2020 13:41:47 +0300
Subject: RDMA/mlx5: Introduce ODP prefetch counter
Patch-mainline: v5.9-rc1
Git-commit: d473f4dc2f95c8c856b1659ced3502802b7d2fbe
References: jsc#SLE-15175

For debugging purpose it will be easier to understand if prefetch works
okay if it has its own counter. Introduce ODP prefetch counter and count
per MR the total number of prefetched pages.

In addition remove comment which is not relevant anymore and anyway not in
the correct place.

Link: https://lore.kernel.org/r/20200621104147.53795-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx5/odp.c      |   19 ++++++++++---------
 drivers/infiniband/hw/mlx5/restrack.c |    3 +++
 include/rdma/ib_verbs.h               |    1 +
 3 files changed, 14 insertions(+), 9 deletions(-)

--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -929,11 +929,6 @@ next_mr:
 		if (ret < 0)
 			goto srcu_unlock;
 
-		/*
-		 * When prefetching a page, page fault is generated
-		 * in order to bring the page to the main memory.
-		 * In the current flow, page faults are being counted.
-		 */
 		mlx5_update_odp_stats(mr, faults, ret);
 
 		npages += ret;
@@ -1771,12 +1766,17 @@ static void mlx5_ib_prefetch_mr_work(str
 	struct prefetch_mr_work *work =
 		container_of(w, struct prefetch_mr_work, work);
 	u32 bytes_mapped = 0;
+	int ret;
 	u32 i;
 
-	for (i = 0; i < work->num_sge; ++i)
-		pagefault_mr(work->frags[i].mr, work->frags[i].io_virt,
-			     work->frags[i].length, &bytes_mapped,
-			     work->pf_flags);
+	for (i = 0; i < work->num_sge; ++i) {
+		ret = pagefault_mr(work->frags[i].mr, work->frags[i].io_virt,
+				   work->frags[i].length, &bytes_mapped,
+				   work->pf_flags);
+		if (ret <= 0)
+			continue;
+		mlx5_update_odp_stats(work->frags[i].mr, prefetch, ret);
+	}
 
 	destroy_prefetch_work(work);
 }
@@ -1832,6 +1832,7 @@ static int mlx5_ib_prefetch_sg_list(stru
 				   &bytes_mapped, pf_flags);
 		if (ret < 0)
 			goto out;
+		mlx5_update_odp_stats(mr, prefetch, ret);
 	}
 	ret = 0;
 
--- a/drivers/infiniband/hw/mlx5/restrack.c
+++ b/drivers/infiniband/hw/mlx5/restrack.c
@@ -99,6 +99,9 @@ int mlx5_ib_fill_stat_mr_entry(struct sk
 		    msg, "page_invalidations",
 		    atomic64_read(&mr->odp_stats.invalidations)))
 		goto err_table;
+	if (rdma_nl_stat_hwcounter_entry(msg, "page_prefetch",
+					 atomic64_read(&mr->odp_stats.prefetch)))
+		goto err_table;
 
 	nla_nest_end(msg, table_attr);
 	return 0;
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2269,6 +2269,7 @@ struct rdma_netdev_alloc_params {
 struct ib_odp_counters {
 	atomic64_t faults;
 	atomic64_t invalidations;
+	atomic64_t prefetch;
 };
 
 struct ib_counters {