From patchwork Mon Sep 14 17:24:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Wang X-Patchwork-Id: 1363833 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20161025 header.b=ukPXw99f; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BqtcT1snpz9sTR for ; Tue, 15 Sep 2020 03:28:25 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726094AbgINR17 (ORCPT ); Mon, 14 Sep 2020 13:27:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726353AbgINR0e (ORCPT ); Mon, 14 Sep 2020 13:26:34 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5DE0C061788 for ; Mon, 14 Sep 2020 10:26:32 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id hr13so499024pjb.3 for ; Mon, 14 Sep 2020 10:26:32 -0700 (PDT) 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=PQr51oLt7gFvXdGEi4RaoFMJAvJLCKvLDQkYyMQ+TnE=; b=ukPXw99fFce5QP/Wfa0z3Q4vl+10VKzHKklnQFvqoY4iIz+W4BJ7MKf8BlEEkxu2dn 2J1jBCybOoPXBnkqri7YFsAwoqX8lQERggtl10pCRV7UEXqsotC2UbPGXIvpn5clOgSX +u1TDy1kPwIdJJkTxqOvjpVveO/Vec7pH/DNpsANWAJyj5BsbIcUSRzc9WKdEruxTRrY g230U8qUlWTEyxP7UaVZ8TFkOL2edjyHs9od9WFqvMPpTI27M4NWYn+LQLVBdFpfpqNJ f5N1KSOwaToDrTMoh4Ea9rgMx6gVNHQMmM8i/zrkI/nL5gxzZtQJ9W1FsJPvljOUHQNR OB4w== 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=PQr51oLt7gFvXdGEi4RaoFMJAvJLCKvLDQkYyMQ+TnE=; b=X6kbyJMivy+ccR/TuAwLTy19gN6b/emhxKRdb7ZmqGOWI1apmOGyZLBtoXYDJpTQAO lQ10iQnU9VaA0F/FtyaEx7ewm7oGBc3iCG2x92usAVvDJF/zWy2gcaUz9hLMw9IgpU9Z O+Zp6uofCHT1huTHTlb8XHBdGwiRp0VtApVKZhwuCQv8dKQ6+B6eE1hk+kgMxKtP9pLx lkoIxJxQkuSC22av3bDCjRz08pQTQrE1NA7L6/W9b2nY273HXLziMXwlAmSz4oxRjAsy oVOo/4HqEkC9NCiEZCHAdKQPvoLiNXqAdq78wYNzf5yJBYwu0HKgdU8cStjqvcOncDTB YI8A== X-Gm-Message-State: AOAM532y+XjeHMB6zhSD9qBO+gtfbkQi5c+FMRh39WTNtKOmyzduY9Kz mxii+sGHYm2mveroP0MWVt8IVy2y9Ng= X-Google-Smtp-Source: ABdhPJy5d2Vp/j9Lr4okRSrVE8uSrBJKS+z9eiiFHItwr39nG+gSO+Ru8FEdpGtrDul1Q8DgiI92lMrPIVE= X-Received: from weiwan.svl.corp.google.com ([2620:15c:2c4:201:1ea0:b8ff:fe75:cf08]) (user=weiwan job=sendgmr) by 2002:a17:902:ab88:b029:d1:9be2:c683 with SMTP id f8-20020a170902ab88b02900d19be2c683mr15031435plr.24.1600104391252; Mon, 14 Sep 2020 10:26:31 -0700 (PDT) Date: Mon, 14 Sep 2020 10:24:53 -0700 In-Reply-To: <20200914172453.1833883-1-weiwan@google.com> Message-Id: <20200914172453.1833883-7-weiwan@google.com> Mime-Version: 1.0 References: <20200914172453.1833883-1-weiwan@google.com> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog Subject: [RFC PATCH net-next 6/6] net: improve napi threaded config From: Wei Wang To: "David S . Miller" , netdev@vger.kernel.org Cc: Jakub Kicinski , Eric Dumazet , Paolo Abeni , Hannes Frederic Sowa , Felix Fietkau , Wei Wang Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This commit mainly addresses the threaded config to make the switch between softirq based and kthread based NAPI processing not require a device down/up. It also moves the kthread_create() call to the sysfs handler when user tries to enable "threaded" on napi, and properly handles the kthread_create() failure. This is because certain drivers do not have the napi created and linked to the dev when dev_open() is called. So the previous implementation does not work properly there. Signed-off-by: Wei Wang --- net/core/dev.c | 49 +++++++++++++++++++++++++------------------- net/core/net-sysfs.c | 9 +++----- 2 files changed, 31 insertions(+), 27 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index ab8af727058b..9f7df61f7c9a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1489,17 +1489,24 @@ EXPORT_SYMBOL(netdev_notify_peers); static int napi_threaded_poll(void *data); -static void napi_thread_start(struct napi_struct *n) +static int napi_kthread_create(struct napi_struct *n) { - if (test_bit(NAPI_STATE_THREADED, &n->state) && !n->thread) - n->thread = kthread_create(napi_threaded_poll, n, "%s-%d", - n->dev->name, n->napi_id); + int err = 0; + + n->thread = kthread_create(napi_threaded_poll, n, "%s-%d", + n->dev->name, n->napi_id); + if (IS_ERR(n->thread)) { + err = PTR_ERR(n->thread); + pr_err("kthread_create failed with err %d\n", err); + n->thread = NULL; + } + + return err; } static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack) { const struct net_device_ops *ops = dev->netdev_ops; - struct napi_struct *n; int ret; ASSERT_RTNL(); @@ -1531,9 +1538,6 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack) if (!ret && ops->ndo_open) ret = ops->ndo_open(dev); - list_for_each_entry(n, &dev->napi_list, dev_list) - napi_thread_start(n); - netpoll_poll_enable(dev); if (ret) @@ -1584,6 +1588,7 @@ static void napi_thread_stop(struct napi_struct *n) if (!n->thread) return; kthread_stop(n->thread); + clear_bit(NAPI_STATE_THREADED, &n->state); n->thread = NULL; } @@ -4266,7 +4271,7 @@ int gro_normal_batch __read_mostly = 8; static inline void ____napi_schedule(struct softnet_data *sd, struct napi_struct *napi) { - if (napi->thread) { + if (test_bit(NAPI_STATE_THREADED, &napi->state)) { wake_up_process(napi->thread); return; } @@ -6623,25 +6628,25 @@ static void init_gro_hash(struct napi_struct *napi) int napi_set_threaded(struct napi_struct *n, bool threaded) { - ASSERT_RTNL(); + int err = 0; - if (n->dev->flags & IFF_UP) - return -EBUSY; + ASSERT_RTNL(); if (threaded == !!test_bit(NAPI_STATE_THREADED, &n->state)) return 0; - if (threaded) + if (threaded) { + if (!n->thread) { + err = napi_kthread_create(n); + if (err) + goto out; + } set_bit(NAPI_STATE_THREADED, &n->state); - else + } else { clear_bit(NAPI_STATE_THREADED, &n->state); + } - /* if the device is initializing, nothing todo */ - if (test_bit(__LINK_STATE_START, &n->dev->state)) - return 0; - - napi_thread_stop(n); - napi_thread_start(n); - return 0; +out: + return err; } EXPORT_SYMBOL(napi_set_threaded); @@ -6686,6 +6691,7 @@ void napi_disable(struct napi_struct *n) msleep(1); hrtimer_cancel(&n->timer); + napi_thread_stop(n); clear_bit(NAPI_STATE_DISABLE, &n->state); } @@ -6806,6 +6812,7 @@ static int napi_thread_wait(struct napi_struct *napi) while (!kthread_should_stop() && !napi_disable_pending(napi)) { if (test_bit(NAPI_STATE_SCHED, &napi->state)) { + WARN_ON(!list_empty(&napi->poll_list)); __set_current_state(TASK_RUNNING); return 0; } diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 0172457a1bfe..48b7582a0372 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -608,11 +608,6 @@ static ssize_t threaded_store(struct device *dev, goto unlock; } - if (netdev->flags & IFF_UP) { - ret = -EBUSY; - goto unlock; - } - bmap = __alloc_thread_bitmap(netdev, &bits); if (!bmap) { ret = -ENOMEM; @@ -625,7 +620,9 @@ static ssize_t threaded_store(struct device *dev, i = 0; list_for_each_entry(n, &netdev->napi_list, dev_list) { - napi_set_threaded(n, test_bit(i, bmap)); + ret = napi_set_threaded(n, test_bit(i, bmap)); + if (ret) + goto free_unlock; i++; } ret = len;