From 6c5c9581044dd6e0cd284ab653502fb9264f08b6 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Tue, 28 Aug 2018 14:44:28 +0200 Subject: [PATCH] net: add napi_if_scheduled_mark_missed The function napi_if_scheduled_mark_missed is used to check if the NAPI context is scheduled, if so set NAPIF_STATE_MISSED and return true. Used by the AF_XDP zero-copy i40e Tx code implementation in order to make sure that irq affinity is honored by the napi context. Signed-off-by: Magnus Karlsson Signed-off-by: Alexei Starovoitov --- include/linux/netdevice.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ca5ab98053c8..4271f6b4e419 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -535,6 +535,32 @@ static inline void napi_synchronize(const struct napi_struct *n) barrier(); } +/** + * napi_if_scheduled_mark_missed - if napi is running, set the + * NAPIF_STATE_MISSED + * @n: NAPI context + * + * If napi is running, set the NAPIF_STATE_MISSED, and return true if + * NAPI is scheduled. + **/ +static inline bool napi_if_scheduled_mark_missed(struct napi_struct *n) +{ + unsigned long val, new; + + do { + val = READ_ONCE(n->state); + if (val & NAPIF_STATE_DISABLE) + return true; + + if (!(val & NAPIF_STATE_SCHED)) + return false; + + new = val | NAPIF_STATE_MISSED; + } while (cmpxchg(&n->state, val, new) != val); + + return true; +} + enum netdev_queue_state_t { __QUEUE_STATE_DRV_XOFF, __QUEUE_STATE_STACK_XOFF,