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authorMoshe Lazer <moshel@mellanox.com>2016-10-27 16:36:42 +0300
committerDoug Ledford <dledford@redhat.com>2016-11-16 20:03:44 -0500
commit6bc1a656ab9f57f0112823b4a36930c9a29d1f89 (patch)
tree6e76546703284ab7d3e1a25c389b31511ff930f8 /drivers/infiniband
parent16b0e0695a73b68d8ca40288c8f9614ef208917b (diff)
IB/mlx5: Resolve soft lock on massive reg MRs
When calling reg_mr of large MRs (e.g. 4GB) from multiple processes and MR caches can't supply the required amount of MRs the slow-path of MR allocation may be used. In this case we need to serialize the slow-path between the processes to avoid soft lock. Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters') Signed-off-by: Moshe Lazer <moshel@mellanox.com> Signed-off-by: Maor Gottlieb <maorg@mellanox.com> Reviewed-by: Eli Cohen <eli@mellanox.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/hw/mlx5/mlx5_ib.h2
-rw-r--r--drivers/infiniband/hw/mlx5/mr.c6
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index dcdcd195fe53..7d689903c87c 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -626,6 +626,8 @@ struct mlx5_ib_dev {
struct mlx5_ib_resources devr;
struct mlx5_mr_cache cache;
struct timer_list delay_timer;
+ /* Prevents soft lock on massive reg MRs */
+ struct mutex slow_path_mutex;
int fill_delay;
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
struct ib_odp_caps odp_caps;
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index d4ad672b905b..4e9012463c37 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -610,6 +610,7 @@ int mlx5_mr_cache_init(struct mlx5_ib_dev *dev)
int err;
int i;
+ mutex_init(&dev->slow_path_mutex);
cache->wq = alloc_ordered_workqueue("mkey_cache", WQ_MEM_RECLAIM);
if (!cache->wq) {
mlx5_ib_warn(dev, "failed to create work queue\n");
@@ -1182,9 +1183,12 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
goto error;
}
- if (!mr)
+ if (!mr) {
+ mutex_lock(&dev->slow_path_mutex);
mr = reg_create(NULL, pd, virt_addr, length, umem, ncont,
page_shift, access_flags);
+ mutex_unlock(&dev->slow_path_mutex);
+ }
if (IS_ERR(mr)) {
err = PTR_ERR(mr);