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Commit 9ead3527 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'rhashtable-next' 

Thomas Graf says:

====================
rhashtable updates on top of Herbert's work

Patch 1 is a bugfix for an RCU splash I encountered while testing.
Patch 2 & 3 are pure cleanups. Patch 4 disables automatic shrinking
by default as discussed in previous thread. Patch 5 removes some
rhashtable internal knowledge from nft_hash and fixes another RCU
splash.

I've pushed various rhashtable tests (Netlink, nft) together with a
Makefile to a git tree [0] for easier stress testing.

[0] https://github.com/tgraf/rhashtable


====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 27cd5452 6b6f302c

include/linux/rhashtable.h

+18 −12
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;
@@ -134,12 +136,10 @@ struct rhashtable_params { 
 * @run_work: Deferred worker to expand/shrink asynchronously

 * @mutex: Mutex to protect current/future table swapping

 * @lock: Spin lock to protect walker list

 * @being_destroyed: True if table is set up for destruction

 */

struct rhashtable {

	struct bucket_table __rcu	*tbl;

	atomic_t			nelems;

	bool                            being_destroyed;

	unsigned int			key_len;

	unsigned int			elasticity;

	struct rhashtable_params	p;
@@ -208,13 +208,13 @@ static inline unsigned int rht_key_hashfn( 
	struct rhashtable *ht, const struct bucket_table *tbl,

	const void *key, const struct rhashtable_params params)

{

	unsigned hash;

	unsigned int hash;



	/* params must be equal to ht->p if it isn't constant. */

	if (!__builtin_constant_p(params.key_len))

		hash = ht->p.hashfn(key, ht->key_len, tbl->hash_rnd);

	else if (params.key_len) {

		unsigned key_len = params.key_len;

		unsigned int key_len = params.key_len;



		if (params.hashfn)

			hash = params.hashfn(key, key_len, tbl->hash_rnd);
@@ -224,7 +224,7 @@ static inline unsigned int rht_key_hashfn( 
			hash = jhash2(key, key_len / sizeof(u32),

				      tbl->hash_rnd);

	} else {

		unsigned key_len = ht->p.key_len;

		unsigned int key_len = ht->p.key_len;



		if (params.hashfn)

			hash = params.hashfn(key, key_len, tbl->hash_rnd);
@@ -332,6 +332,9 @@ int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU); 
void *rhashtable_walk_next(struct rhashtable_iter *iter);

void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU);



void rhashtable_free_and_destroy(struct rhashtable *ht,

				 void (*free_fn)(void *ptr, void *arg),

				 void *arg);

void rhashtable_destroy(struct rhashtable *ht);



#define rht_dereference(p, ht) \
@@ -512,7 +515,7 @@ static inline void *rhashtable_lookup_fast( 
	};

	const struct bucket_table *tbl;

	struct rhash_head *he;

	unsigned hash;

	unsigned int hash;



	rcu_read_lock();
@@ -539,6 +542,7 @@ static inline void *rhashtable_lookup_fast( 
	return NULL;

}



/* Internal function, please use rhashtable_insert_fast() instead */

static inline int __rhashtable_insert_fast(

	struct rhashtable *ht, const void *key, struct rhash_head *obj,

	const struct rhashtable_params params)
@@ -550,8 +554,8 @@ static inline int __rhashtable_insert_fast( 
	struct bucket_table *tbl, *new_tbl;

	struct rhash_head *head;

	spinlock_t *lock;

	unsigned elasticity;

	unsigned hash;

	unsigned int elasticity;

	unsigned int hash;

	int err;



restart:
@@ -585,8 +589,8 @@ static inline int __rhashtable_insert_fast( 
	if (unlikely(rht_grow_above_100(ht, tbl))) {

slow_path:

		spin_unlock_bh(lock);

		rcu_read_unlock();

		err = rhashtable_insert_rehash(ht);

		rcu_read_unlock();

		if (err)

			return err;
@@ -711,6 +715,7 @@ static inline int rhashtable_lookup_insert_key( 
	return __rhashtable_insert_fast(ht, key, obj, params);

}



/* Internal function, please use rhashtable_remove_fast() instead */

static inline int __rhashtable_remove_fast(

	struct rhashtable *ht, struct bucket_table *tbl,

	struct rhash_head *obj, const struct rhashtable_params params)
@@ -718,7 +723,7 @@ static inline int __rhashtable_remove_fast( 
	struct rhash_head __rcu **pprev;

	struct rhash_head *he;

	spinlock_t * lock;

	unsigned hash;

	unsigned int hash;

	int err = -ENOENT;



	hash = rht_head_hashfn(ht, tbl, obj, params);
@@ -782,7 +787,8 @@ 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

+50 −19
Original line number Diff line number Diff line
@@ -153,7 +153,7 @@ static struct bucket_table *rhashtable_last_table(struct rhashtable *ht, 
	return new_tbl;

}



static int rhashtable_rehash_one(struct rhashtable *ht, unsigned old_hash)

static int rhashtable_rehash_one(struct rhashtable *ht, unsigned int old_hash)

{

	struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht);

	struct bucket_table *new_tbl = rhashtable_last_table(ht,
@@ -162,7 +162,7 @@ static int rhashtable_rehash_one(struct rhashtable *ht, unsigned old_hash) 
	int err = -ENOENT;

	struct rhash_head *head, *next, *entry;

	spinlock_t *new_bucket_lock;

	unsigned new_hash;

	unsigned int new_hash;



	rht_for_each(entry, old_tbl, old_hash) {

		err = 0;
@@ -199,7 +199,8 @@ static int rhashtable_rehash_one(struct rhashtable *ht, unsigned old_hash) 
	return err;

}



static void rhashtable_rehash_chain(struct rhashtable *ht, unsigned old_hash)

static void rhashtable_rehash_chain(struct rhashtable *ht,

				    unsigned int old_hash)

{

	struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht);

	spinlock_t *old_bucket_lock;
@@ -244,7 +245,7 @@ static int rhashtable_rehash_table(struct rhashtable *ht) 
	struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht);

	struct bucket_table *new_tbl;

	struct rhashtable_walker *walker;

	unsigned old_hash;

	unsigned int old_hash;



	new_tbl = rht_dereference(old_tbl->future_tbl, ht);

	if (!new_tbl)
@@ -324,11 +325,12 @@ static int rhashtable_expand(struct rhashtable *ht) 
static int rhashtable_shrink(struct rhashtable *ht)

{

	struct bucket_table *new_tbl, *old_tbl = rht_dereference(ht->tbl, ht);

	unsigned size = roundup_pow_of_two(atomic_read(&ht->nelems) * 3 / 2);

	unsigned int size;

	int err;



	ASSERT_RHT_MUTEX(ht);



	size = roundup_pow_of_two(atomic_read(&ht->nelems) * 3 / 2);

	if (size < ht->p.min_size)

		size = ht->p.min_size;
@@ -357,20 +359,17 @@ static void rht_deferred_worker(struct work_struct *work) 


	ht = container_of(work, struct rhashtable, run_work);

	mutex_lock(&ht->mutex);

	if (ht->being_destroyed)

		goto unlock;



	tbl = rht_dereference(ht->tbl, ht);

	tbl = rhashtable_last_table(ht, tbl);



	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);



unlock:

	mutex_unlock(&ht->mutex);



	if (err)
@@ -379,9 +378,9 @@ static void rht_deferred_worker(struct work_struct *work) 


static bool rhashtable_check_elasticity(struct rhashtable *ht,

					struct bucket_table *tbl,

					unsigned hash)

					unsigned int hash)

{

	unsigned elasticity = ht->elasticity;

	unsigned int elasticity = ht->elasticity;

	struct rhash_head *head;



	rht_for_each(head, tbl, hash)
@@ -431,7 +430,7 @@ int rhashtable_insert_slow(struct rhashtable *ht, const void *key, 
			   struct bucket_table *tbl)

{

	struct rhash_head *head;

	unsigned hash;

	unsigned int hash;

	int err;



	tbl = rhashtable_last_table(ht, tbl);
@@ -781,21 +780,53 @@ int rhashtable_init(struct rhashtable *ht, 
EXPORT_SYMBOL_GPL(rhashtable_init);



/**

 * rhashtable_destroy - destroy hash table

 * rhashtable_free_and_destroy - free elements and destroy hash table

 * @ht:		the hash table to destroy

 * @free_fn:	callback to release resources of element

 * @arg:	pointer passed to free_fn

 *

 * Stops an eventual async resize. If defined, invokes free_fn for each

 * element to releasal resources. Please note that RCU protected

 * readers may still be accessing the elements. Releasing of resources

 * must occur in a compatible manner. Then frees the bucket array.

 *

 * Frees the bucket array. This function is not rcu safe, therefore the caller

 * has to make sure that no resizing may happen by unpublishing the hashtable

 * and waiting for the quiescent cycle before releasing the bucket array.

 * This function will eventually sleep to wait for an async resize

 * to complete. The caller is responsible that no further write operations

 * occurs in parallel.

 */

void rhashtable_destroy(struct rhashtable *ht)

void rhashtable_free_and_destroy(struct rhashtable *ht,

				 void (*free_fn)(void *ptr, void *arg),

				 void *arg)

{

	ht->being_destroyed = true;

	const struct bucket_table *tbl;

	unsigned int i;



	cancel_work_sync(&ht->run_work);



	mutex_lock(&ht->mutex);

	bucket_table_free(rht_dereference(ht->tbl, ht));

	tbl = rht_dereference(ht->tbl, ht);

	if (free_fn) {

		for (i = 0; i < tbl->size; i++) {

			struct rhash_head *pos, *next;



			for (pos = rht_dereference(tbl->buckets[i], ht),

			     next = !rht_is_a_nulls(pos) ?

					rht_dereference(pos->next, ht) : NULL;

			     !rht_is_a_nulls(pos);

			     pos = next,

			     next = !rht_is_a_nulls(pos) ?

					rht_dereference(pos->next, ht) : NULL)

				free_fn(rht_obj(ht, pos), arg);

		}

	}



	bucket_table_free(tbl);

	mutex_unlock(&ht->mutex);

}

EXPORT_SYMBOL_GPL(rhashtable_free_and_destroy);



void rhashtable_destroy(struct rhashtable *ht)

{

	return rhashtable_free_and_destroy(ht, NULL, NULL);

}

EXPORT_SYMBOL_GPL(rhashtable_destroy);

net/netfilter/nft_hash.c

+8 −18
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,
@@ -187,26 +188,15 @@ static int nft_hash_init(const struct nft_set *set, 
	return rhashtable_init(priv, &params);

}



static void nft_hash_destroy(const struct nft_set *set)

static void nft_free_element(void *ptr, void *arg)

{

	struct rhashtable *priv = nft_set_priv(set);

	const struct bucket_table *tbl;

	struct nft_hash_elem *he;

	struct rhash_head *pos, *next;

	unsigned int i;



	/* Stop an eventual async resizing */

	priv->being_destroyed = true;

	mutex_lock(&priv->mutex);



	tbl = rht_dereference(priv->tbl, priv);

	for (i = 0; i < tbl->size; i++) {

		rht_for_each_entry_safe(he, pos, next, tbl, i, node)

			nft_hash_elem_destroy(set, he);

	nft_hash_elem_destroy((const struct nft_set *)arg, ptr);

}

	mutex_unlock(&priv->mutex);



	rhashtable_destroy(priv);

static void nft_hash_destroy(const struct nft_set *set)

{

	rhashtable_free_and_destroy(nft_set_priv(set), nft_free_element,

				    (void *)set);

}



static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,

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)