> -----Original Message----- > From: netdev-ow...@vger.kernel.org [mailto:netdev-ow...@vger.kernel.org] > On Behalf Of Joe Perches > Sent: Wednesday, April 12, 2017 11:57 AM > To: gfree.w...@foxmail.com; da...@davemloft.net; kuz...@ms2.inr.ac.ru; > jmor...@namei.org; netdev@vger.kernel.org > Cc: Gao Feng <f...@ikuai8.com> > Subject: Re: [PATCH net-next v2 1/1] net: ipv4: Refine the ipv4_default_advmss > > On Wed, 2017-04-12 at 10:32 +0800, gfree.w...@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.
Yes. I thought about writing it with the way you mentioned, but gave up. But i could follow you this time. Best Regards Feng
