It is currently not used.

It was in fact never used since its introduction in commit ff5a0b421cb2
("mptcp: faster active backup recovery"). It was probably initially
added to struct pm_nl_pernet during the development of this commit,
before being added to struct mptcp_pernet in ctrl.c, but not removed
from the first place.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm_kernel.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index e84c381aa3a4e2ad8a05e4b0daa7a5e8daf2c35b..52ae6304b311189ab927857ab74a9ee44ac6d76a 100644
--- a/net/mptcp/pm_kernel.c
+++ b/net/mptcp/pm_kernel.c
@@ -19,7 +19,6 @@ struct pm_nl_pernet {
 	spinlock_t		lock;
 	struct list_head	endp_list;
 	unsigned int		endpoints;
-	unsigned int		stale_loss_cnt;
 	unsigned int		endp_signal_max;
 	unsigned int		endp_subflow_max;
 	unsigned int		limit_add_addr_accepted;
@@ -1461,7 +1460,6 @@ static int __net_init pm_nl_init_net(struct net *net)
 	/* Cit. 2 subflows ought to be enough for anybody. */
 	pernet->limit_extra_subflows = 2;
 	pernet->next_id = 1;
-	pernet->stale_loss_cnt = 4;
 	spin_lock_init(&pernet->lock);
 
 	/* No need to initialize other pernet fields, the struct is zeroed at

-- 
2.51.0