From: David Ahern <dsah...@gmail.com>
ip route (for example) uses ll_name_to_index to convert the user given
device name to an index. At the moment ll_name_to_index uses if_nametoindex
which is ioctl based and does not cache the result. When using a batch file
this means the same device lookups can be done repeatedly adding unnecessary
overhead (socket + ioctl + close for each device lookup).
Add a new function, ll_link_get, to send a netlink based RTM_GETLINK. If
successful, cache the result in idx_head and name_head so future lookups
can re-use the entry. Update ll_name_to_index to use ll_link_get over
if_nametoindex.
With this change the time to install 720,022 routes with 2 ecmp nexthops
where the nexthop device is given is reduced from 30.7 seconds to 17.6
seconds.
Signed-off-by: David Ahern <dsah...@gmail.com>
---
lib/ll_map.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 43 insertions(+), 1 deletion(-)
diff --git a/lib/ll_map.c b/lib/ll_map.c
index 8e8a0b1e9c9d..46c78df08c11 100644
--- a/lib/ll_map.c
+++ b/lib/ll_map.c
@@ -192,6 +192,46 @@ int ll_index_to_flags(unsigned idx)
return im ? im->flags : -1;
}
+static int ll_link_get(const char *name)
+{
+ struct {
+ struct nlmsghdr n;
+ struct ifinfomsg ifm;
+ char buf[1024];
+ } req = {
+ .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+ .n.nlmsg_flags = NLM_F_REQUEST,
+ .n.nlmsg_type = RTM_GETLINK,
+ };
+ __u32 filt_mask = RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS;
+ struct rtnl_handle rth = {};
+ struct nlmsghdr *answer;
+ int rc = 0;
+
+ if (rtnl_open(&rth, 0) < 0)
+ return 0;
+
+ addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
+ addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name,
+ strlen(name) + 1);
+
+ if (rtnl_talk(&rth, &req.n, &answer) < 0)
+ goto out;
+
+ /* add entry to cache */
+ rc = ll_remember_index(answer, NULL);
+ if (!rc) {
+ struct ifinfomsg *ifm = NLMSG_DATA(answer);
+
+ rc = ifm->ifi_index;
+ }
+
+ free(answer);
+out:
+ rtnl_close(&rth);
+ return rc;
+}
+
unsigned ll_name_to_index(const char *name)
{
const struct ll_cache *im;
@@ -204,7 +244,9 @@ unsigned ll_name_to_index(const char *name)
if (im)
return im->index;
- idx = if_nametoindex(name);
+ idx = ll_link_get(name);
+ if (idx == 0)
+ idx = if_nametoindex(name);
if (idx == 0)
idx = ll_idx_a2n(name);
return idx;
--
2.11.0
