From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] ipvs: improved SH fallback strategy Date: Mon, 23 Sep 2013 23:42:50 +0400 Message-ID: <524099BA.5020303@cogentembedded.com> References: <20130923115139.GA15034@eldamar.org.uk> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130923115139.GA15034@eldamar.org.uk> Sender: lvs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Alexander Frolkin Cc: Julian Anastasov , lvs-devel@vger.kernel.org, Wensong Zhang , Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Hello. On 09/23/2013 03:51 PM, Alexander Frolkin wrote: > Improve the SH fallback realserver selection strategy. > With sh and sh-fallback, if a realserver is down, this attempts to > distribute the traffic that would have gone to that server evenly > among the remaining servers. > Signed-off-by: Alexander Frolkin > --- > diff --git a/net/netfilter/ipvs/ip_vs_sh.c b/net/netfilter/ipvs/ip_vs_sh.c > index f16c027..1676354 100644 > --- a/net/netfilter/ipvs/ip_vs_sh.c > +++ b/net/netfilter/ipvs/ip_vs_sh.c > @@ -120,22 +120,35 @@ static inline struct ip_vs_dest * > ip_vs_sh_get_fallback(struct ip_vs_service *svc, struct ip_vs_sh_state *s, > const union nf_inet_addr *addr, __be16 port) > { > - unsigned int offset; > - unsigned int hash; > + unsigned int offset, roffset; > + unsigned int hash, ihash; > struct ip_vs_dest *dest; > > - for (offset = 0; offset < IP_VS_SH_TAB_SIZE; offset++) { > - hash = ip_vs_sh_hashkey(svc->af, addr, port, offset); > - dest = rcu_dereference(s->buckets[hash].dest); > - if (!dest) > - break; > - if (is_unavailable(dest)) > - IP_VS_DBG_BUF(6, "SH: selected unavailable server " > - "%s:%d (offset %d)", > + ihash = ip_vs_sh_hashkey(svc->af, addr, port, 0); > + dest = rcu_dereference(s->buckets[ihash].dest); > + Empty line net needed here (and it wasn't there in the original code). > + if (!dest) > + return NULL; > + Here too. > + if (is_unavailable(dest)) { > + IP_VS_DBG_BUF(6, "SH: selected unavailable server " > + "%s:%d, reselecting", > + IP_VS_DBG_ADDR(svc->af, &dest->addr), > + ntohs(dest->port)); > + for (offset = 0; offset < IP_VS_SH_TAB_SIZE; offset++) { > + roffset = (offset + ihash) % IP_VS_SH_TAB_SIZE; > + hash = ip_vs_sh_hashkey(svc->af, addr, port, roffset); > + dest = rcu_dereference(s->buckets[hash].dest); > + if (is_unavailable(dest)) > + IP_VS_DBG_BUF(6, "SH: selected unavailable " > + "server %s:%d (offset %d), reselecting", > IP_VS_DBG_ADDR(svc->af, &dest->addr), WBR, Sergei