rhashtable: Check for count mismatch while iterating in selftest
Verify whether both the lock and RCU protected iterators see all
test entries before and after expanding and shrinking has been
performed. Also verify whether the number of entries in the hashtable
remains stable during expansion and shrinking.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index e5f5e69..c7e987a 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -653,15 +653,15 @@
return 0;
}
-static void test_bucket_stats(struct rhashtable *ht,
- struct bucket_table *tbl,
- bool quiet)
+static void test_bucket_stats(struct rhashtable *ht, bool quiet)
{
- unsigned int cnt, i, total = 0;
+ unsigned int cnt, rcu_cnt, i, total = 0;
struct test_obj *obj;
+ struct bucket_table *tbl;
+ tbl = rht_dereference_rcu(ht->tbl, ht);
for (i = 0; i < tbl->size; i++) {
- cnt = 0;
+ rcu_cnt = cnt = 0;
if (!quiet)
pr_info(" [%#4x/%zu]", i, tbl->size);
@@ -673,6 +673,13 @@
pr_cont(" [%p],", obj);
}
+ rht_for_each_entry_rcu(obj, tbl->buckets[i], node)
+ rcu_cnt++;
+
+ if (rcu_cnt != cnt)
+ pr_warn("Test failed: Chain count mismach %d != %d",
+ cnt, rcu_cnt);
+
if (!quiet)
pr_cont("\n [%#x] first element: %p, chain length: %u\n",
i, tbl->buckets[i], cnt);
@@ -680,6 +687,9 @@
pr_info(" Traversal complete: counted=%u, nelems=%zu, entries=%d\n",
total, ht->nelems, TEST_ENTRIES);
+
+ if (total != ht->nelems || total != TEST_ENTRIES)
+ pr_warn("Test failed: Total count mismatch ^^^");
}
static int __init test_rhashtable(struct rhashtable *ht)
@@ -710,8 +720,7 @@
}
rcu_read_lock();
- tbl = rht_dereference_rcu(ht->tbl, ht);
- test_bucket_stats(ht, tbl, true);
+ test_bucket_stats(ht, true);
test_rht_lookup(ht);
rcu_read_unlock();
@@ -735,6 +744,10 @@
rcu_read_unlock();
}
+ rcu_read_lock();
+ test_bucket_stats(ht, true);
+ rcu_read_unlock();
+
pr_info(" Deleting %d keys\n", TEST_ENTRIES);
for (i = 0; i < TEST_ENTRIES; i++) {
u32 key = i * 2;