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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 BFE3CC433E0 for ; Wed, 24 Mar 2021 11:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 754BB61A0E for ; Wed, 24 Mar 2021 11:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234457AbhCXLBf (ORCPT ); Wed, 24 Mar 2021 07:01:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231237AbhCXLBc (ORCPT ); Wed, 24 Mar 2021 07:01:32 -0400 Received: from mail-qk1-x72e.google.com (mail-qk1-x72e.google.com [IPv6:2607:f8b0:4864:20::72e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EAC9C061763; Wed, 24 Mar 2021 04:01:32 -0700 (PDT) Received: by mail-qk1-x72e.google.com with SMTP id q26so12257634qkm.6; Wed, 24 Mar 2021 04:01:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=E01fHFK8B0CwUT/NlAoEwx2voqfnNCEWOzjDvw2m6n4=; b=NY7yAw8cgzTULkuOmQLe2iktQaWt4puHb7S1TNfzJGWZHdxtmXziQBVPoR8kCKTFyn +Yz3LuSF505XWHMfmShaq4dINFkf7D/si3f92ZufU9SQt7w7Kmal8sIzimlIC4BqiXdu 4sROjr2nLVbDC5t+0JYOUe1av60D0+MHPpWc6DIbOfOw+Tvfg009WQlpu+BtOLpIQV/U OnGCIS1DM0wDVi4oZIAL216VlCG/xmFKx5bdG2JmVp4MHiNi+DJJRB3RaCfsAgDeV7Nn N+KBIbxgQe+aRb2AoiXomVW4ZromWvkZvHY8HGdCHCYWcLMsU3lq1wa0dD+N8PatFXGx ZD6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=E01fHFK8B0CwUT/NlAoEwx2voqfnNCEWOzjDvw2m6n4=; b=AUNDkNTr5+0VedCBimKq+86r+awWk2W7dWKKGgL/RIZ7B4Tdy/1JExkg7LTyLRrfxA 1rDnBQ+24Uvj63sHOWr5E6SC75g26DmZJW9NmtM4gQQqzBFaaEJimvk2nDzTJJXLwS7W WVZ8oYPoIzThDbcs3c4VcDXle4lGNqFwhE4FI8fmspwy62Dwc0RaoIpC7XcQHMCSrpDj cOUgqnquFSjr+Smxr8uu1ozms7DrYEfoCSCFvoU9Mb5r1mR/D/WNamaQrFZW4rR6Urd+ KOc7vuwCevSR3W/GFXQ6KzT+ubZISYmxzTqAesjYPhSAl+9DUEXolS7nKIWL6BPx564A FQzw== X-Gm-Message-State: AOAM531lMmTJSPEBhStdbCE5+FV9FUsgfW8eYp3nFnWBjoMqFMjhcvgK vaEL1Cy5OGyLRTvX0wUiQbVrxcwxsRQPzgp0BGAu5W5fdEKWYg== X-Google-Smtp-Source: ABdhPJytap/S1ltJf1op8lX8miHVyKrZXtLRsceZm6unF3ougp9sQStKo5N+OsDjX6fVMFoTNGd+nFyhniTnt3rIt8s= X-Received: by 2002:a37:6c3:: with SMTP id 186mr2289123qkg.279.1616583691583; Wed, 24 Mar 2021 04:01:31 -0700 (PDT) MIME-Version: 1.0 References: <20210324030923.17203-1-yejune.deng@gmail.com> In-Reply-To: From: Yejune Deng Date: Wed, 24 Mar 2021 19:01:19 +0800 Message-ID: Subject: Re: [PATCH 1/2] net: ipv4: route.c: add likely() statements To: Leon Romanovsky Cc: David Miller , yoshfuji@linux-ipv6.org, dsahern@kernel.org, Jakub Kicinski , netdev , Linux Kernel Mailing List , yejune@gmail.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org My reasons are as following: ipv4_confirm_neigh() belongs to ipv4_dst_ops that family is AF_INET, and ipv4_neigh_lookup() is also added likely() when rt->rt_gw_family is equal to AF_INET. On Wed, Mar 24, 2021 at 6:34 PM Leon Romanovsky wrote: > > On Wed, Mar 24, 2021 at 11:09:22AM +0800, Yejune Deng wrote: > > Add likely() statements in ipv4_confirm_neigh() for 'rt->rt_gw_family > > == AF_INET'. > > Why? Such macros are beneficial in only specific cases, most of the time, > likely/unlikely is cargo cult. > > > > > Signed-off-by: Yejune Deng > > --- > > net/ipv4/route.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/ipv4/route.c b/net/ipv4/route.c > > index fa68c2612252..5762d9bc671c 100644 > > --- a/net/ipv4/route.c > > +++ b/net/ipv4/route.c > > @@ -440,7 +440,7 @@ static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) > > struct net_device *dev = dst->dev; > > const __be32 *pkey = daddr; > > > > - if (rt->rt_gw_family == AF_INET) { > > + if (likely(rt->rt_gw_family == AF_INET)) { > > pkey = (const __be32 *)&rt->rt_gw4; > > } else if (rt->rt_gw_family == AF_INET6) { > > return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); > > -- > > 2.29.0 > >