rhashtable: add schedule points

edumazet · davem330 · commit ae6da1f503ab · 2018-03-31T23:25:39.000-04:00
Rehashing and destroying large hash table takes a lot of time,
and happens in process context. It is safe to add cond_resched()
in rhashtable_rehash_table() and rhashtable_free_and_destroy()

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
@@ -333,6 +333,7 @@ static int rhashtable_rehash_table(struct rhashtable *ht)
 		err = rhashtable_rehash_chain(ht, old_hash);
 		if (err)
 			return err;
+		cond_resched();
 	}
 
 	/* Publish the new table pointer. */
@@ -1112,6 +1113,7 @@ void rhashtable_free_and_destroy(struct rhashtable *ht,
 		for (i = 0; i < tbl->size; i++) {
 			struct rhash_head *pos, *next;
 
+			cond_resched();
 			for (pos = rht_dereference(*rht_bucket(tbl, i), ht),
 			     next = !rht_is_a_nulls(pos) ?
 					rht_dereference(pos->next, ht) : NULL;
