Commit b9f5f52c authored Jun 03, 2008 by Stephen Hemminger Committed by David S. Miller Jun 03, 2008

net: neighbour table ABI problem



The neighbor table time of last use information is returned in the
incorrect unit. Kernel to user space ABI's need to use USER_HZ (or
milliseconds), otherwise the application has to try and discover the
real system HZ value which is problematic.  Linux has standardized on
keeping USER_HZ consistent (100hz) even when kernel is running
internally at some other value.

This change is small, but it breaks the ABI for older version of
iproute2 utilities.  But these utilities are already broken since they
are looking at the psched_hz values which are completely different. So
let's just go ahead and fix both kernel and user space. Older
utilities will just print wrong values.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 57c511d8

net/core/neighbour.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -2057,9 +2057,9 @@ static int neigh_fill_info(struct sk_buff skb, struct neighbour neigh,
		goto nla_put_failure;
		}

		ci.ndm_used = now - neigh->used;
		ci.ndm_confirmed = now - neigh->confirmed;
		ci.ndm_updated = now - neigh->updated;
		ci.ndm_used = jiffies_to_clock_t(now - neigh->used);
		ci.ndm_confirmed = jiffies_to_clock_t(now - neigh->confirmed);
		ci.ndm_updated = jiffies_to_clock_t(now - neigh->updated);
		ci.ndm_refcnt = atomic_read(&neigh->refcnt) - 1;
		read_unlock_bh(&neigh->lock);

Admin message