From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 BACC9C433DB for ; Sat, 13 Feb 2021 19:39:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F18C64DD5 for ; Sat, 13 Feb 2021 19:39:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229691AbhBMTjf (ORCPT ); Sat, 13 Feb 2021 14:39:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229647AbhBMTj3 (ORCPT ); Sat, 13 Feb 2021 14:39:29 -0500 Received: from mail-il1-x129.google.com (mail-il1-x129.google.com [IPv6:2607:f8b0:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4360FC061574 for ; Sat, 13 Feb 2021 11:38:49 -0800 (PST) Received: by mail-il1-x129.google.com with SMTP id d20so2327188ilo.4 for ; Sat, 13 Feb 2021 11:38:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=6MCizH7ETWIi/+xtBstJ/VHU029nE1lufmMJc+8QoLs=; b=KAkL1cp1nMGRGK4TkkcT1S/4H/5SYVAIADvVukGRsD3KPzHhgWwQv2+ylkJmt8Ury/ NgzTgzRkTpBUC3zXEHsZwYzBUXUsnOu/xKsG5kXs8DSQl4vP535F/cMNh9UUWIihLzbx o4/OQaoOE+G4xd12FCoY1l8AtbdTrK7TLMmm6Qo5jqx3H/mYRFmlfLuW0frQYHQj5Pbm RRcgYyszM6M/4TUtLtL087cdCGnsmyMTph20GVKnSTsn4X+/TSTLRQOX7302Tu4JPB3R IhCsr2KWXwvYBYW+M8AEKqbPiW7Cxtn7yeBhraih2OvgT1U3/gKck3TEZBk4jEf5sdyw sipg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=6MCizH7ETWIi/+xtBstJ/VHU029nE1lufmMJc+8QoLs=; b=uSEmKLF0EC/j2KA/MWhrG+0HipB6Xw2tkxoV84jMo8V+JRlPGkMPVFNubqeHmlqpPw jHp1f1JMKFZOVGhz7flMBpko2cdYQbYIoAQ0lgdalMYaE06yLzP63s/Zig2pCg325YxZ 6OcyLEuiAW+P3VtdZ0pObdcsdCZNsi5rIh3ubRgT642mir9iJc0mIp7odx+6OBo94KHt /XOLv/HaxPsO2yaMGArLsy5KvsZwOW4gHgbU+w7ADiLVJoNYj4Q3PDX++7T0FcUMdgDk AAl9FIKevrucJ0lvkOPPjm5M6ifAE2HEeEreVy14py57NKQD6838h7wy3rUFiZmkbeXY PeCQ== X-Gm-Message-State: AOAM530fFza2pCKguSt6tBqN31nF+k0bnnRJZXVfsfzl37D/CNkDDA26 pjlDDrGCdhK1c3JdZ5ftGTY= X-Google-Smtp-Source: ABdhPJymdqigQZG68jb0Zy/EEmMJP40Wi4GTm7iuwbX7pWmIG2nVgmM0zeDUdPB4TfKJj/yk9aTfpQ== X-Received: by 2002:a05:6e02:4ca:: with SMTP id f10mr7194424ils.112.1613245128672; Sat, 13 Feb 2021 11:38:48 -0800 (PST) Received: from Davids-MacBook-Pro.local ([8.48.134.33]) by smtp.googlemail.com with ESMTPSA id o19sm6322832ioh.47.2021.02.13.11.38.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 13 Feb 2021 11:38:48 -0800 (PST) Subject: Re: [RFC PATCH 04/13] nexthop: Add implementation of resilient next-hop groups To: Petr Machata , netdev@vger.kernel.org Cc: David Ahern , "David S. Miller" , Jakub Kicinski , Ido Schimmel References: From: David Ahern Message-ID: Date: Sat, 13 Feb 2021 12:38:47 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/8/21 1:42 PM, Petr Machata wrote: > diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c > index 5d560d381070..4ce282b0a65f 100644 > --- a/net/ipv4/nexthop.c > +++ b/net/ipv4/nexthop.c> @@ -734,6 +834,22 @@ static struct nexthop *nexthop_select_path_mp(struct nh_group *nhg, int hash) > return rc; > } > > +static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash) > +{ > + struct nh_res_table *res_table = rcu_dereference(nhg->res_table); > + u32 bucket_index = hash % res_table->num_nh_buckets; Have you considered requiring the number of buckets to be a power of 2 to avoid the modulo in the hot path? Seems like those are the more likely size options.