Commit 4ffa1d1c authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: adopt try_cmpxchg() in napi_{enable|disable}() 



This makes code a bit cleaner.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1462160c

net/core/dev.c

+5 −9
Original line number Diff line number Diff line
@@ -6397,8 +6397,8 @@ void napi_disable(struct napi_struct *n) 
	might_sleep();

	set_bit(NAPI_STATE_DISABLE, &n->state);



	for ( ; ; ) {

	val = READ_ONCE(n->state);

	do {

		if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {

			usleep_range(20, 200);

			continue;
@@ -6406,10 +6406,7 @@ void napi_disable(struct napi_struct *n) 


		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;

		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);



		if (cmpxchg(&n->state, val, new) == val)

			break;

	}

	} while (!try_cmpxchg(&n->state, &val, new));



	hrtimer_cancel(&n->timer);
@@ -6426,16 +6423,15 @@ EXPORT_SYMBOL(napi_disable); 
 */

void napi_enable(struct napi_struct *n)

{

	unsigned long val, new;

	unsigned long new, val = READ_ONCE(n->state);



	do {

		val = READ_ONCE(n->state);

		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));



		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);

		if (n->dev->threaded && n->thread)

			new |= NAPIF_STATE_THREADED;

	} while (cmpxchg(&n->state, val, new) != val);

	} while (!try_cmpxchg(&n->state, &val, new));

}

EXPORT_SYMBOL(napi_enable);