From: Leon Romanovsky <leon@kernel.org>
To: Yejune Deng <yejune.deng@gmail.com>
Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org,
kuba@kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, yejune@gmail.com
Subject: Re: [PATCH 1/2] net: ipv4: route.c: add likely() statements
Date: Wed, 24 Mar 2021 12:34:52 +0200 [thread overview]
Message-ID: <YFsVzP6P9l0aaIVo@unreal> (raw)
In-Reply-To: <20210324030923.17203-1-yejune.deng@gmail.com>
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 <yejune.deng@gmail.com>
> ---
> 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
>
next prev parent reply other threads:[~2021-03-24 10:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 3:09 [PATCH 1/2] net: ipv4: route.c: add likely() statements Yejune Deng
2021-03-24 10:34 ` Leon Romanovsky [this message]
2021-03-24 11:01 ` Yejune Deng
2021-03-24 12:19 ` Leon Romanovsky
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