On 02/06/15 17:01, roopa wrote:
On 6/1/15, 9:46 AM, Robert Shearman wrote:
Parse RTA_ENCAP attribute for one path and multipath routes. The encap
length is stored in a newly added field to fib_nh, nh_encap_len,
although this is added to a padding hole in the structure so that it
doesn't increase the size at all. The encap data itself is stored at
the end of the array of nexthops. Whilst this means that retrieval
isn't optimal, especially if there are multiple nexthops, this avoids
the memory cost of an extra pointer, as well as any potential change
to the cache or instruction layout that could cause a performance
impact.
Currently, the dst structure allocated to represent the destination of
the packet and used for retrieving the encap by the encap-type
interface has been grown through the addition of the rt_encap_len and
rt_encap fields. This isn't desirable and could be fixed by defining a
new destination type with operations copied from the normal case,
other than the addition of the get_encap operation.
Signed-off-by: Robert Shearman <rshea...@brocade.com>
...
@@ -434,6 +445,83 @@ static int fib_detect_death(struct fib_info *fi,
int order,
return 1;
}
+static int fib_total_encap(struct fib_config *cfg)
+{
+ struct net *net = cfg->fc_nlinfo.nl_net;
+ int total_encap_len = 0;
+
+ if (cfg->fc_mp) {
+ int remaining = cfg->fc_mp_len;
+ struct rtnexthop *rtnh = cfg->fc_mp;
+
+ while (rtnh_ok(rtnh, remaining)) {
+ struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
+ int attrlen;
+
+ attrlen = rtnh_attrlen(rtnh);
+ nla = nla_find(attrs, attrlen, RTA_ENCAP);
+ if (nla) {
+ struct net_device *dev;
+ int len;
+
+ dev = __dev_get_by_index(net,
+ rtnh->rtnh_ifindex);
+ if (!dev)
+ return -EINVAL;
+
+ /* Determine space required */
+ len = rtnl_parse_encap(dev, nla, NULL);
+ if (len < 0)
+ return len;
+
+ total_encap_len += len;
+ }
+
+ rtnh = rtnh_next(rtnh, &remaining);
+ }
+ } else {
+ if (cfg->fc_encap) {
+ struct net_device *dev;
+ int len;
+
+ dev = __dev_get_by_index(net, cfg->fc_oif);
+ if (!dev)
+ return -EINVAL;
+
+ /* Determine space required */
+ len = rtnl_parse_encap(dev, cfg->fc_encap, NULL);
+ if (len < 0)
+ return len;
+
+ total_encap_len += len;
+ }
+ }
+
+ return total_encap_len;
+}
we could avoid parsing and finding this device twice, if fib_nh just
held a pointer to the encap_info
(or tunnel info) ?. And the encap_info/tun_info could be refcounted and
shared between
nexthops ?. In my implementation i have just a pointer to parsed encap
state
in fib_nh
Right - I took the approach here to avoid any extra memory use if encap
isn't in use for the nexthop/route, and to avoid any potential
performance penalty caused by extra cache misses. It would certainly
make things simpler if those weren't concerns. I'd appreciate input from
the community on this.
@@ -1403,6 +1418,15 @@ static void rt_set_nexthop(struct rtable *rt,
__be32 daddr,
#ifdef CONFIG_IP_ROUTE_CLASSID
rt->dst.tclassid = nh->nh_tclassid;
#endif
+
+ nh_encap = fib_get_nh_encap(fi, nh);
+ if (unlikely(nh_encap)) {
+ rt->rt_encap = kmemdup(nh_encap, nh->nh_encap_len,
+ GFP_KERNEL);
+ if (rt->rt_encap)
+ rt->rt_encap_len = nh->nh_encap_len;
+ }
+
And..., you could make the rtable point to the same encap info.
Ack.
Thanks,
Rob
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
