[PATCH v3 2/3] IB/core: Shuffle locks in ib_port_data to save memory

From: Anand Khoje
Date: Wed Jun 09 2021 - 01:56:04 EST


pahole shows two 4-byte holes in struct ib_port_data after
pkey_list_lock and netdev_lock respectively.

Shuffling the netdev_lock to be after pkey_list_lock, this
shaves off eight bytes from the struct.

Suggested-by: Haakon Bugge <haakon.bugge@xxxxxxxxxx>
Signed-off-by: Anand Khoje <anand.a.khoje@xxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>

---

v1 -> v2:
- Split the v1 patch in 3 patches as per Leon's suggestion.
v2 -> v3:
- No changes.

---
drivers/infiniband/core/cache.c | 6 +-----
include/rdma/ib_verbs.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 7e2f3699b898..41cbec516424 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2175,11 +2175,13 @@ struct ib_port_data {
struct ib_port_immutable immutable;

spinlock_t pkey_list_lock;
+
+ spinlock_t netdev_lock;
+
struct list_head pkey_list;

struct ib_port_cache cache;

- spinlock_t netdev_lock;
struct net_device __rcu *netdev;
struct hlist_node ndev_hash_link;
struct rdma_port_counter port_counter;
--
2.27.0