From patchwork Wed Sep 30 19:21:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Wang X-Patchwork-Id: 259814 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=-21.1 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 498D9C4727C for ; Wed, 30 Sep 2020 19:22:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E6B2C20709 for ; Wed, 30 Sep 2020 19:22:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bGqrpYKx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730056AbgI3TWa (ORCPT ); Wed, 30 Sep 2020 15:22:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbgI3TW3 (ORCPT ); Wed, 30 Sep 2020 15:22:29 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B311DC061755 for ; Wed, 30 Sep 2020 12:22:29 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id c26so1492764pgl.9 for ; Wed, 30 Sep 2020 12:22:29 -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=2Fv/RrWoLcbM9P0duMxErv9yg1yz6MFdGnuq0GYXBxw=; b=bGqrpYKx4Jc85dJFg9s7r6LwTE4wK+xHdPMw5nhn6JvQkO95uy1HOLptRKtZyqNs/4 VVVMqVuXxnJBSGPUVvPKOHrLtbeutECHE52oHAsp1GJXqTc3WRF2/AFL7KWeYLPD1El6 /urin9faYJMfx5hnlqykz2ulraKaaJSCJ5u+slffb9aocxPNjBLsOOr2BwqMd/LCraFe C1eguknDpkjVlmAbux0EzKCBbPyOhaokxnbSpGERXHSXRCSpKfxZ7AaiVFTSDcRaAUTX rAI3CF2vb3328HZFRKT8buakfa54LERHre4LNHFtoD5AMBn0+xVa8e56j8RS4EdptwcE YevA== 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=2Fv/RrWoLcbM9P0duMxErv9yg1yz6MFdGnuq0GYXBxw=; b=AWX/eKCL/gbMSHyVld814GFy/0VVkSoCV4ijDaZIP+02QbQrbyMwM0jZ/0s/8Dc0ON yUt2Ssa94Zy8l2eLKYnoI3DoHe1bwX8ggLOgtQZoMRiMzFdSdnJp89k4mw7o9s8CE5NR nvgnatsQWIcaS8lTz2T5ypcuqKhzxvjMHkd1p62316rPGuARewN20m7yycz+PJ52tkBv HyQqTLh1TqzTcaAMkDwRM0dPBMVVsR0jSwlxd4pmjfVVQTwcqhVL/FyFzOQnrpW8nw+2 v5w5zvxUduj6V5MCWhn4BEHX05Ct6Niy29c050jxvq98oPTNYo9SOxy/jTvzsViW9V9N ro1g== X-Gm-Message-State: AOAM530coAegGQRWvsooMestmcISK0IvucnbdaikLlVdYgsgAcHyoNsL Xpnso739G/OGf4SQbukB8xoFa9W0VNM= X-Google-Smtp-Source: ABdhPJzeh5hXnILpNcKopyCOuPM/7zTUE1URK1dGFn/J+M6UOzvBzEuSjc7sdRzX/enu68NuEnYwspqfn5U= 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:a17:90a:940c:: with SMTP id r12mr9582pjo.1.1601493748282; Wed, 30 Sep 2020 12:22:28 -0700 (PDT) Date: Wed, 30 Sep 2020 12:21:37 -0700 In-Reply-To: <20200930192140.4192859-1-weiwan@google.com> Message-Id: <20200930192140.4192859-3-weiwan@google.com> Mime-Version: 1.0 References: <20200930192140.4192859-1-weiwan@google.com> X-Mailer: git-send-email 2.28.0.709.gb0816b6eb0-goog Subject: [PATCH net-next 2/5] net: add sysfs attribute to control napi threaded mode From: Wei Wang To: "David S . Miller" , netdev@vger.kernel.org Cc: Eric Dumazet , Jakub Kicinski , Hannes Frederic Sowa , Paolo Abeni , Felix Fietkau , Wei Wang Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni this patch adds a new sysfs attribute to the network device class. Said attribute is a bitmask that allows controlling the threaded mode for all the napi instances of the given network device. The threaded mode can be switched only if related network device is down. Signed-off-by: Paolo Abeni Signed-off-by: Hannes Frederic Sowa Signed-off-by: Wei Wang --- net/core/net-sysfs.c | 103 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index efec66fa78b7..fe81b344447d 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -538,6 +538,108 @@ static ssize_t phys_switch_id_show(struct device *dev, } static DEVICE_ATTR_RO(phys_switch_id); +static unsigned long *__alloc_thread_bitmap(struct net_device *netdev, + int *bits) +{ + struct napi_struct *n; + + *bits = 0; + list_for_each_entry(n, &netdev->napi_list, dev_list) + (*bits)++; + + return kmalloc_array(BITS_TO_LONGS(*bits), sizeof(unsigned long), + GFP_ATOMIC | __GFP_ZERO); +} + +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; + unsigned long *bmap; + size_t count = 0; + int i, bits; + + if (!rtnl_trylock()) + return restart_syscall(); + + if (!dev_isalive(netdev)) + goto unlock; + + bmap = __alloc_thread_bitmap(netdev, &bits); + if (!bmap) { + count = -ENOMEM; + goto unlock; + } + + i = 0; + list_for_each_entry(n, &netdev->napi_list, dev_list) { + if (test_bit(NAPI_STATE_THREADED, &n->state)) + set_bit(i, bmap); + i++; + } + + count = bitmap_print_to_pagebuf(true, buf, bmap, bits); + kfree(bmap); + +unlock: + rtnl_unlock(); + + return count; +} + +static ssize_t threaded_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct net_device *netdev = to_net_dev(dev); + struct napi_struct *n; + unsigned long *bmap; + int i, bits; + size_t ret; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + if (!rtnl_trylock()) + return restart_syscall(); + + if (!dev_isalive(netdev)) { + ret = len; + goto unlock; + } + + if (netdev->flags & IFF_UP) { + ret = -EBUSY; + goto unlock; + } + + bmap = __alloc_thread_bitmap(netdev, &bits); + if (!bmap) { + ret = -ENOMEM; + goto unlock; + } + + ret = bitmap_parselist(buf, bmap, bits); + if (ret) + goto free_unlock; + + i = 0; + list_for_each_entry(n, &netdev->napi_list, dev_list) { + napi_set_threaded(n, test_bit(i, bmap)); + i++; + } + ret = len; + +free_unlock: + kfree(bmap); + +unlock: + rtnl_unlock(); + return ret; +} +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 +672,7 @@ 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);