[PATCH 32/32] net: Make softirq vector masking finegrained on release_sock()

Frederic Weisbecker
2019-02-12T17:16:19Z

This is a usage example of spin_lock_bh_mask(). NET_RX, TIMER and
TASKLET are the three softirqs that have been reported by lockdep to
be used for this socket lock, at least on my own usecases.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Pavan Kondeti <pkondeti@codeaurora.org>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
---
net/core/sock.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 6aa2e7e0b4fb..24ca1cdacfe3 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2795,7 +2795,9 @@ EXPORT_SYMBOL(lock_sock_nested);

void release_sock(struct sock *sk)
{
- spin_lock_bh(&sk->sk_lock.slock);
+ unsigned int bh;
+
+ bh = spin_lock_bh_mask(&sk->sk_lock.slock, BIT(NET_RX_SOFTIRQ) | BIT(TIMER_SOFTIRQ) | BIT(TASKLET_SOFTIRQ));
if (sk->sk_backlog.tail)
__release_sock(sk);

@@ -2808,7 +2810,7 @@ void release_sock(struct sock *sk)
sock_release_ownership(sk);
if (waitqueue_active(&sk->sk_lock.wq))
wake_up(&sk->sk_lock.wq);
- spin_unlock_bh(&sk->sk_lock.slock);
+ spin_unlock_bh_mask(&sk->sk_lock.slock, bh);
}
EXPORT_SYMBOL(release_sock);

--
2.17.1