From: Joe Perches <joe@perches.com>
To: gfree.wind@foxmail.com, davem@davemloft.net,
kuznet@ms2.inr.ac.ru, jmorris@namei.org, netdev@vger.kernel.org
Cc: Gao Feng <fgao@ikuai8.com>
Subject: Re: [PATCH net-next v2 1/1] net: ipv4: Refine the ipv4_default_advmss
Date: Tue, 11 Apr 2017 20:57:24 -0700 [thread overview]
Message-ID: <1491969444.17839.30.camel@perches.com> (raw)
In-Reply-To: <1491964333-69989-1-git-send-email-gfree.wind@foxmail.com>
On Wed, 2017-04-12 at 10:32 +0800, gfree.wind@foxmail.com wrote:
> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
more trivia:
> @@ -1250,14 +1250,11 @@ static void set_class_tag(struct rtable *rt, u32 tag)
>
> static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
> {
> - unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
> + unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
> + unsigned int advmss = max_t(unsigned int, dst->dev->mtu - header_size,
> + ip_rt_min_advmss);
>
> - if (advmss == 0) {
> - advmss = max_t(unsigned int, dst->dev->mtu - 40,
> - ip_rt_min_advmss);
> - if (advmss > 65535 - 40)
> - advmss = 65535 - 40;
> - }
> + advmss = min(advmss, IPV4_MAX_PMTU - header_size);
> return advmss;
> }
This would probably be simpler to read as:
return min(advmss, IPV4_MAX_PMTU - header_size);
though it's almost certain that the compiler emits identical
object code.
next prev parent reply other threads:[~2017-04-12 3:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-12 2:32 [PATCH net-next v2 1/1] net: ipv4: Refine the ipv4_default_advmss gfree.wind
2017-04-12 3:57 ` Joe Perches [this message]
2017-04-12 4:13 ` Gao Feng
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