rhashtable: Disable automatic shrinking by default
Introduce a new bool automatic_shrinking to require the
user to explicitly opt-in to automatic shrinking of tables.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 0e1f975..ae26c49 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -2,7 +2,7 @@
* Resizable, Scalable, Concurrent Hash Table
*
* Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
- * Copyright (c) 2014 Thomas Graf <tgraf@suug.ch>
+ * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch>
* Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
*
* Code partially derived from nft_hash
@@ -104,6 +104,7 @@
* @min_size: Minimum size while shrinking
* @nulls_base: Base value to generate nulls marker
* @insecure_elasticity: Set to true to disable chain length checks
+ * @automatic_shrinking: Enable automatic shrinking of tables
* @locks_mul: Number of bucket locks to allocate per cpu (default: 128)
* @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash)
* @obj_hashfn: Function to hash object
@@ -118,6 +119,7 @@
unsigned int min_size;
u32 nulls_base;
bool insecure_elasticity;
+ bool automatic_shrinking;
size_t locks_mul;
rht_hashfn_t hashfn;
rht_obj_hashfn_t obj_hashfn;
@@ -784,7 +786,8 @@
goto out;
atomic_dec(&ht->nelems);
- if (rht_shrink_below_30(ht, tbl))
+ if (unlikely(ht->p.automatic_shrinking &&
+ rht_shrink_below_30(ht, tbl)))
schedule_work(&ht->run_work);
out: