From c264c3dee9f20bad1f42ef5821300791291d0f77 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Wed, 17 Oct 2007 13:26:41 -0700 Subject: [PATCH] napi_synchronize: waiting for NAPI Some drivers with shared NAPI need a synchronization barrier. Also suggested by Benjamin Herrenschmidt for EMAC. Signed-off-by: Stephen Hemminger Signed-off-by: Jeff Garzik --- include/linux/netdevice.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 39dd83b183..a5e2dc1f0d 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -407,6 +407,24 @@ static inline void napi_enable(struct napi_struct *n) clear_bit(NAPI_STATE_SCHED, &n->state); } +#ifdef CONFIG_SMP +/** + * napi_synchronize - wait until NAPI is not running + * @n: napi context + * + * Wait until NAPI is done being scheduled on this context. + * Waits till any outstanding processing completes but + * does not disable future activations. + */ +static inline void napi_synchronize(const struct napi_struct *n) +{ + while (test_bit(NAPI_STATE_SCHED, &n->state)) + msleep(1); +} +#else +# define napi_synchronize(n) barrier() +#endif + /* * The DEVICE structure. * Actually, this whole structure is a big mistake. It mixes I/O -- 2.39.5