From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Subject: [PATCH bpf-next 04/11] net: add napi_if_scheduled_mark_missed Date: Tue, 28 Aug 2018 14:44:28 +0200 Message-ID: <20180828124435.30578-5-bjorn.topel@gmail.com> References: <20180828124435.30578-1-bjorn.topel@gmail.com> Cc: michael.lundkvist@ericsson.com, willemdebruijn.kernel@gmail.com, john.fastabend@gmail.com, jakub.kicinski@netronome.com, neerav.parikh@intel.com, mykyta.iziumtsev@linaro.org, francois.ozog@linaro.org, ilias.apalodimas@linaro.org, brian.brooks@linaro.org, u9012063@gmail.com, pavel@fastnetmon.com, qi.z.zhang@intel.com To: bjorn.topel@gmail.com, magnus.karlsson@intel.com, magnus.karlsson@gmail.com, alexander.h.duyck@intel.com, alexander.duyck@gmail.com, ast@kernel.org, brouer@redhat.com, daniel@iogearbox.net, netdev@vger.kernel.org, jesse.brandeburg@intel.com, anjali.singhai@intel.com, peter.waskiewicz.jr@intel.com Return-path: Received: from mga02.intel.com ([134.134.136.20]:48894 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727224AbeH1QjZ (ORCPT ); Tue, 28 Aug 2018 12:39:25 -0400 In-Reply-To: <20180828124435.30578-1-bjorn.topel@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Magnus Karlsson 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 --- 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, -- 2.17.1