On Tue, Jul 28, 2015 at 2:42 PM, Gleb Smirnoff <gleb...@freebsd.org> wrote:
> Ermal, > > see comments inlined, > > On Thu, Jul 02, 2015 at 06:10:42PM +0000, Ermal Luçi wrote: > E> Author: eri > E> Date: Thu Jul 2 18:10:41 2015 > E> New Revision: 285051 > E> URL: https://svnweb.freebsd.org/changeset/base/285051 > E> > E> Log: > E> Avoid doing multiple route lookups for the same destination IP during > forwarding > E> > E> ip_forward() does a route lookup for testing this packet can be sent > to a known destination, > E> it also can do another route lookup if it detects that an ICMP > redirect is needed, > E> it forgets all of this and handovers to ip_output() to do the same > lookup yet again. > E> > E> This optimisation just does one route lookup during the forwarding > path and handovers that to be considered by ip_output(). > E> > E> Differential Revision: https://reviews.freebsd.org/D2964 > E> Approved by: ae, gnn(mentor) > E> MFC after: 1 week > E> > E> Modified: > E> head/sys/netinet/ip_input.c > E> > E> Modified: head/sys/netinet/ip_input.c > E> > ============================================================================== > E> --- head/sys/netinet/ip_input.c Thu Jul 2 17:30:59 2015 > (r285050) > E> +++ head/sys/netinet/ip_input.c Thu Jul 2 18:10:41 2015 > (r285051) > E> @@ -897,6 +897,7 @@ ip_forward(struct mbuf *m, int srcrt) > E> struct ip *ip = mtod(m, struct ip *); > E> struct in_ifaddr *ia; > E> struct mbuf *mcopy; > E> + struct sockaddr_in *sin; > E> struct in_addr dest; > E> struct route ro; > E> int error, type = 0, code = 0, mtu = 0; > E> @@ -925,7 +926,22 @@ ip_forward(struct mbuf *m, int srcrt) > E> } > E> #endif > E> > E> - ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m)); > E> + bzero(&ro, sizeof(ro)); > E> + sin = (struct sockaddr_in *)&ro.ro_dst; > E> + sin->sin_family = AF_INET; > E> + sin->sin_len = sizeof(*sin); > E> + sin->sin_addr = ip->ip_dst; > E> +#ifdef RADIX_MPATH > E> + rtalloc_mpath_fib(&ro, > E> + ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), > E> + M_GETFIB(m)); > E> +#else > E> + in_rtalloc_ign(&ro, 0, M_GETFIB(m)); > E> +#endif > E> + if (ro.ro_rt != NULL) { > E> + ia = ifatoia(ro.ro_rt->rt_ifa); > E> + ifa_ref(&ia->ia_ifa); > E> + } > E> #ifndef IPSEC > E> /* > E> * 'ia' may be NULL if there is no route for this destination. > E> @@ -934,6 +950,7 @@ ip_forward(struct mbuf *m, int srcrt) > E> */ > E> if (!srcrt && ia == NULL) { > E> icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0); > E> + RO_RTFREE(&ro); > E> return; > E> } > > Here the ifa reference is leaked upon return. > > Gleb, the improvement on the ifa_ref not needed is something to look at but the ifa_ref here is not lost since ia == NULL, no? Maybe i am missing something else. Also can we put this on a review? > > But don't hurry with fixing that :) Actually you don't need to ifa_ref() > in this function. You acquired a reference on rtentry in in_rtalloc_ign() > and hold it until RO_RTFREE(). And the rtentry itself always holds a > reference on the ifa. So, there is no reason to put extra reference on > the ifa. > > The ip_output() was already improved in r262747. And ip_forward() can > also be. The only place that touches ia after RO_RTFREE() is EMSGSIZE > handling, this can be moved up before RO_RTFREE(). > > Here is suggested patch. Ermal and Oliver, can you please test/benchmark > it? > > -- > Totus tuus, Glebius. > -- Ermal _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"