ipvs: unify the formula to estimate the overhead of processing connections

lc and wlc use the same formula, but lblc and lblcr use another one. There
is no reason for using two different formulas for the lc variants.

The formula used by lc is used by all the lc variants in this patch.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Wensong Zhang <wensong@linux-vs.org>
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 17b01b2..e74da41e 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -1243,6 +1243,20 @@
 /* CONFIG_IP_VS_NFCT */
 #endif
 
+static inline unsigned int
+ip_vs_dest_conn_overhead(struct ip_vs_dest *dest)
+{
+	/*
+	 * We think the overhead of processing active connections is 256
+	 * times higher than that of inactive connections in average. (This
+	 * 256 times might not be accurate, we will change it later) We
+	 * use the following formula to estimate the overhead now:
+	 *		  dest->activeconns*256 + dest->inactconns
+	 */
+	return (atomic_read(&dest->activeconns) << 8) +
+		atomic_read(&dest->inactconns);
+}
+
 #endif /* __KERNEL__ */
 
 #endif	/* _NET_IP_VS_H */