From 4ffa1d1c6842a97e84cfbe56bfcf70edb23608e2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 15 Nov 2022 09:11:00 +0000 Subject: [PATCH] net: adopt try_cmpxchg() in napi_{enable|disable}() This makes code a bit cleaner. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 0c12c7ad04f2..fb943dad9651 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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); + 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);