Commit b5e2c150 authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

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: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ac833bdd

include/linux/rhashtable.h

+5 −2
Original line number Diff line number Diff line
@@ -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 @@ 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:

lib/rhashtable.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

net/netfilter/nft_hash.c

+1 −0
Original line number Diff line number Diff line
@@ -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,

net/netlink/af_netlink.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

net/tipc/socket.c

+1 −0
Original line number Diff line number Diff line
@@ -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)