4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit ae6da1f503abb5a5081f9f6c4a6881de97830f3e upstream.
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@google.com Acked-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- lib/rhashtable.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -250,8 +250,10 @@ 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); @@ -842,6 +844,7 @@ 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;