4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
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 <edumazet@xxxxxxxxxx>
Acked-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
(cherry picked from commit ae6da1f503abb5a5081f9f6c4a6881de97830f3e)
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/rhashtable.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -251,8 +251,10 @@ static int rhashtable_rehash_table(struc
if (!new_tbl)
return 0;
- for (old_hash = 0; old_hash < old_tbl->size; old_hash++)
+ for (old_hash = 0; old_hash < old_tbl->size; old_hash++) {
rhashtable_rehash_chain(ht, old_hash);
+ cond_resched();
+ }
/* Publish the new table pointer. */
rcu_assign_pointer(ht->tbl, new_tbl);
@@ -993,6 +995,7 @@ void rhashtable_free_and_destroy(struct
for (i = 0; i < tbl->size; i++) {
struct rhash_head *pos, *next;
+ cond_resched();
for (pos = rht_dereference(tbl->buckets[i], ht),
next = !rht_is_a_nulls(pos) ?
rht_dereference(pos->next, ht) : NULL;
