From b5e2c150ac914f28a28833b57397bec0b0a2bd5f Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Tue, 24 Mar 2015 20:42:19 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/linux/rhashtable.h | 7 +++++-- lib/rhashtable.c | 2 +- net/netfilter/nft_hash.c | 1 + net/netlink/af_netlink.c | 1 + net/tipc/socket.c | 1 + 5 files changed, 9 insertions(+), 3 deletions(-) diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index 0e1f975ad101..ae26c494e230 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 - * Copyright (c) 2014 Thomas Graf + * Copyright (c) 2014-2015 Thomas Graf * Copyright (c) 2008-2014 Patrick McHardy * * Code partially derived from nft_hash @@ -104,6 +104,7 @@ struct rhashtable; * @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 @@ struct rhashtable_params { 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 @@ static inline int rhashtable_remove_fast( 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: diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 50abe4fec4b8..50374d181148 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -367,7 +367,7 @@ static void rht_deferred_worker(struct work_struct *work) if (rht_grow_above_75(ht, tbl)) rhashtable_expand(ht); - else if (rht_shrink_below_30(ht, tbl)) + else if (ht->p.automatic_shrinking && rht_shrink_below_30(ht, tbl)) rhashtable_shrink(ht); err = rhashtable_rehash_table(ht); diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c index ad3966976cf5..8577a37af18b 100644 --- a/net/netfilter/nft_hash.c +++ b/net/netfilter/nft_hash.c @@ -172,6 +172,7 @@ static const struct rhashtable_params nft_hash_params = { .head_offset = offsetof(struct nft_hash_elem, node), .key_offset = offsetof(struct nft_hash_elem, key), .hashfn = jhash, + .automatic_shrinking = true, }; static int nft_hash_init(const struct nft_set *set, diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index e2f7f28148e0..4caa809dbbe0 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -3142,6 +3142,7 @@ static const struct rhashtable_params netlink_rhashtable_params = { .obj_hashfn = netlink_hash, .obj_cmpfn = netlink_compare, .max_size = 65536, + .automatic_shrinking = true, }; static int __init netlink_proto_init(void) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 094710519477..ee90d74d7516 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -2297,6 +2297,7 @@ static const struct rhashtable_params tsk_rht_params = { .key_len = sizeof(u32), /* portid */ .max_size = 1048576, .min_size = 256, + .automatic_shrinking = true, }; int tipc_sk_rht_init(struct net *net)