[IPV4] fib_trie: Add statistics.

The FIB TRIE code has a bunch of statistics, but the code is hidden
behind an ifdef that was never implemented. Since it was dead code, it
was broken as well.

This patch fixes that by making it a config option.
Signed-off-by: Stephen Hemminger <stephen.hemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/Kconfig

@@ -85,6 +85,13 @@ endchoice
 config IP_FIB_HASH
 	def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
 
+config IP_FIB_TRIE_STATS
+	bool "FIB TRIE statistics"
+	depends on IP_FIB_TRIE
+	---help---
+	  Keep track of statistics on structure of FIB TRIE table.
+	  Useful for testing and measuring TRIE performance.
+
 config IP_MULTIPLE_TABLES
 	bool "IP: policy routing"
 	depends on IP_ADVANCED_ROUTER

net/ipv4/fib_trie.c

@@ -82,7 +82,6 @@
 #include <net/ip_fib.h>
 #include "fib_lookup.h"
 
-#undef CONFIG_IP_FIB_TRIE_STATS
 #define MAX_STAT_DEPTH 32
 
 #define KEYLENGTH (8*sizeof(t_key))
@@ -2119,20 +2118,22 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
 	bytes += sizeof(struct node *) * pointers;
 	seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
 	seq_printf(seq, "Total size: %u  kB\n", (bytes + 1023) / 1024);
+}
 
 #ifdef CONFIG_IP_FIB_TRIE_STATS
-	seq_printf(seq, "Counters:\n---------\n");
-	seq_printf(seq,"gets = %d\n", t->stats.gets);
-	seq_printf(seq,"backtracks = %d\n", t->stats.backtrack);
-	seq_printf(seq,"semantic match passed = %d\n", t->stats.semantic_match_passed);
-	seq_printf(seq,"semantic match miss = %d\n", t->stats.semantic_match_miss);
-	seq_printf(seq,"null node hit= %d\n", t->stats.null_node_hit);
-	seq_printf(seq,"skipped node resize = %d\n", t->stats.resize_node_skipped);
-#ifdef CLEAR_STATS
-	memset(&(t->stats), 0, sizeof(t->stats));
-#endif
-#endif /*  CONFIG_IP_FIB_TRIE_STATS */
+static void trie_show_usage(struct seq_file *seq,
+			    const struct trie_use_stats *stats)
+{
+	seq_printf(seq, "\nCounters:\n---------\n");
+	seq_printf(seq,"gets = %u\n", stats->gets);
+	seq_printf(seq,"backtracks = %u\n", stats->backtrack);
+	seq_printf(seq,"semantic match passed = %u\n", stats->semantic_match_passed);
+	seq_printf(seq,"semantic match miss = %u\n", stats->semantic_match_miss);
+	seq_printf(seq,"null node hit= %u\n", stats->null_node_hit);
+	seq_printf(seq,"skipped node resize = %u\n\n", stats->resize_node_skipped);
 }
+#endif /*  CONFIG_IP_FIB_TRIE_STATS */
+
 
 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
 {
@@ -2163,12 +2164,18 @@ static int fib_triestat_seq_show(struct seq_file *seq, void *v)
 		seq_printf(seq, "Local:\n");
 		trie_collect_stats(trie_local, stat);
 		trie_show_stats(seq, stat);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+		trie_show_usage(seq, &trie_local->stats);
+#endif
 	}
 
 	if (trie_main) {
 		seq_printf(seq, "Main:\n");
 		trie_collect_stats(trie_main, stat);
 		trie_show_stats(seq, stat);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+		trie_show_usage(seq, &trie_main->stats);
+#endif
 	}
 	kfree(stat);