From patchwork Fri Jan 15 00:31:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Wang X-Patchwork-Id: 363353 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92BA3C4332B for ; Fri, 15 Jan 2021 00:32:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7598223AC2 for ; Fri, 15 Jan 2021 00:32:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731336AbhAOAcQ (ORCPT ); Thu, 14 Jan 2021 19:32:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731320AbhAOAcM (ORCPT ); Thu, 14 Jan 2021 19:32:12 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10E12C0613CF for ; Thu, 14 Jan 2021 16:31:32 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id m203so3606662ybf.1 for ; Thu, 14 Jan 2021 16:31:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=OecE8mJTuQ3sRppsTjqxIwKDLyJK9rjkn/l7EUdvJ90=; b=GNQ9+peAbyKPOUtsz5fz0hw4He2lMOo5Py/caCyjOGtOQNN6+klQ7Tfsq/irZqD82A 8QssErXshJHecMrQle53pt/Z0Jhcom3HfLag1hTInDNB4WyE6ksQF2VMak8/CtKBw1PO tWYSDbvc2N0NAWBdBRTeZRuYI6mf0eNGH8HM+JaCQzVeQSO9q8+u+VZqSB7qWG9OVYdx PjG0syacSnHBOy2Qf3CHym6iSHZJ14untSvttmRK7qcG2xoTTSV76wu7IMjyLwhoH4gJ rxHyPKeDdh+e1RhssK4rPKbR+0W0wEulmdaVVN/sj90ntwtgKKte6Cvzg04/zK+RnArG JCqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=OecE8mJTuQ3sRppsTjqxIwKDLyJK9rjkn/l7EUdvJ90=; b=bCmq9pFj3CywhGmRKVZYWtJUb3A71QLgAslIlDBqsawmVrRcSylArThnwbMa5znoRW BrxhR4ekg9hqnTUQWrPPAztUCuMl+2x8BPcvNjOg2PZpwWnmzOKBoH555KbQhucz8ll9 R5l6nYtV+xu9bTeEXFp7ltJXFZZ1sYYzrIO2Z9EIOi1OQXokNCk9cjyicc5J3ZbbdeT8 lbztBtQhxLsUgDqkO0CEJkAVAiIaH6x94aAyk33qVFAkgwlUJvQDHfzGMAAHa6a04iEK 76pVYt4pH48FjWCQaPGj03WG5w7AYbxo0yofm2/MqfmwlY/Oqen88aVkEzXiwdb+kW1T aFOQ== X-Gm-Message-State: AOAM530jwrkKhbm6RI3Wnz7/eXnVoeK2AtKK/I/jo0M9U/TqqhjRHqL9 nrxemmvBTII1mUur9ksQNQwxhIorebo= X-Google-Smtp-Source: ABdhPJxAOj7Zjw5sxXV+Q7v7q4gvisFltRV54G4tkGqPbkbGQvfSK8w5smlhHLOhZ0db0zugsvjSfEaCDs0= Sender: "weiwan via sendgmr" X-Received: from weiwan.svl.corp.google.com ([2620:15c:2c4:201:1ea0:b8ff:fe75:cf08]) (user=weiwan job=sendgmr) by 2002:a25:743:: with SMTP id 64mr13826074ybh.333.1610670691335; Thu, 14 Jan 2021 16:31:31 -0800 (PST) Date: Thu, 14 Jan 2021 16:31:23 -0800 In-Reply-To: <20210115003123.1254314-1-weiwan@google.com> Message-Id: <20210115003123.1254314-4-weiwan@google.com> Mime-Version: 1.0 References: <20210115003123.1254314-1-weiwan@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH net-next v6 3/3] net: add sysfs attribute to control napi threaded mode From: Wei Wang To: David Miller , netdev@vger.kernel.org, Jakub Kicinski Cc: Eric Dumazet , Paolo Abeni , Hannes Frederic Sowa , Felix Fietkau Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds a new sysfs attribute to the network device class. Said attribute provides a per-device control to enable/disable the threaded mode for all the napi instances of the given network device. Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Co-developed-by: Hannes Frederic Sowa Signed-off-by: Hannes Frederic Sowa Co-developed-by: Felix Fietkau Signed-off-by: Felix Fietkau Signed-off-by: Wei Wang --- include/linux/netdevice.h | 2 ++ net/core/dev.c | 28 +++++++++++++++++ net/core/net-sysfs.c | 63 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c24ed232c746..11ae0c9b9350 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -497,6 +497,8 @@ static inline bool napi_complete(struct napi_struct *n) return napi_complete_done(n, 0); } +int dev_set_threaded(struct net_device *dev, bool threaded); + /** * napi_disable - prevent NAPI from scheduling * @n: NAPI context diff --git a/net/core/dev.c b/net/core/dev.c index edcfec1361e9..d5fb95316ea8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6754,6 +6754,34 @@ static int napi_set_threaded(struct napi_struct *n, bool threaded) return err; } +static void dev_disable_threaded_all(struct net_device *dev) +{ + struct napi_struct *napi; + + list_for_each_entry(napi, &dev->napi_list, dev_list) + napi_set_threaded(napi, false); +} + +int dev_set_threaded(struct net_device *dev, bool threaded) +{ + struct napi_struct *napi; + int ret; + + dev->threaded = threaded; + list_for_each_entry(napi, &dev->napi_list, dev_list) { + ret = napi_set_threaded(napi, threaded); + if (ret) { + /* Error occurred on one of the napi, + * reset threaded mode on all napi. + */ + dev_disable_threaded_all(dev); + break; + } + } + + return ret; +} + void netif_napi_add(struct net_device *dev, struct napi_struct *napi, int (*poll)(struct napi_struct *, int), int weight) { diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index daf502c13d6d..2017f8f07b8d 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -538,6 +538,68 @@ static ssize_t phys_switch_id_show(struct device *dev, } static DEVICE_ATTR_RO(phys_switch_id); +static ssize_t threaded_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct net_device *netdev = to_net_dev(dev); + struct napi_struct *n; + bool enabled; + int ret; + + if (!rtnl_trylock()) + return restart_syscall(); + + if (!dev_isalive(netdev)) { + ret = -EINVAL; + goto unlock; + } + + if (list_empty(&netdev->napi_list)) { + ret = -EOPNOTSUPP; + goto unlock; + } + + /* Only return true if all napi have threaded mode. + * The inconsistency could happen when the device driver calls + * napi_disable()/napi_enable() with dev->threaded set to true, + * but napi_kthread_create() fails. + * We return false in this case to remind the user that one or + * more napi did not have threaded mode enabled properly. + */ + list_for_each_entry(n, &netdev->napi_list, dev_list) { + enabled = !!test_bit(NAPI_STATE_THREADED, &n->state); + if (!enabled) + break; + } + + ret = sprintf(buf, fmt_dec, enabled); + +unlock: + rtnl_unlock(); + return ret; +} + +static int modify_napi_threaded(struct net_device *dev, unsigned long val) +{ + struct napi_struct *napi; + int ret; + + if (list_empty(&dev->napi_list)) + return -EOPNOTSUPP; + + ret = dev_set_threaded(dev, !!val); + + return ret; +} + +static ssize_t threaded_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + return netdev_store(dev, attr, buf, len, modify_napi_threaded); +} +static DEVICE_ATTR_RW(threaded); + static struct attribute *net_class_attrs[] __ro_after_init = { &dev_attr_netdev_group.attr, &dev_attr_type.attr, @@ -570,6 +632,7 @@ static struct attribute *net_class_attrs[] __ro_after_init = { &dev_attr_proto_down.attr, &dev_attr_carrier_up_count.attr, &dev_attr_carrier_down_count.attr, + &dev_attr_threaded.attr, NULL, }; ATTRIBUTE_GROUPS(net_class);