rhashtable: remove nulls_base and related code. (9f9a7077) · Commits · 戴 / test

include/linux/rhashtable-types.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -50,7 +50,6 @@ typedef int (rht_obj_cmpfn_t)(struct rhashtable_compare_arg arg,
		* @min_size: Minimum size while shrinking
		* @locks_mul: Number of bucket locks to allocate per cpu (default: 32)
		* @automatic_shrinking: Enable automatic shrinking of tables
		* @nulls_base: Base value to generate nulls marker
		* @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash)
		* @obj_hashfn: Function to hash object
		* @obj_cmpfn: Function to compare key with object
		@@ -64,7 +63,6 @@ struct rhashtable_params {
		u16 min_size;
		bool automatic_shrinking;
		u8 locks_mul;
		u32 nulls_base;
		rht_hashfn_t hashfn;
		rht_obj_hashfn_t obj_hashfn;
		rht_obj_cmpfn_t obj_cmpfn;

include/linux/rhashtable.h

+3 −30

Original line number	Diff line number	Diff line
		@@ -28,25 +28,8 @@
		#include <linux/rhashtable-types.h>
		/*
		* The end of the chain is marked with a special nulls marks which has
		* the following format:
		*
		* +-------+-----------------------------------------------------+-+
		* \| Base \| Hash \|1\|
		* +-------+-----------------------------------------------------+-+
		*
		* Base (4 bits) : Reserved to distinguish between multiple tables.
		* Specified via &struct rhashtable_params.nulls_base.
		* Hash (27 bits): Full hash (unmasked) of first element added to bucket
		* 1 (1 bit) : Nulls marker (always set)
		*
		* The remaining bits of the next pointer remain unused for now.
		* the least significant bit set.
		*/
		#define RHT_BASE_BITS 4
		#define RHT_HASH_BITS 27
		#define RHT_BASE_SHIFT RHT_HASH_BITS

		/* Base bits plus 1 bit for nulls marker */
		#define RHT_HASH_RESERVED_SPACE (RHT_BASE_BITS + 1)

		/* Maximum chain length before rehash
		*
		@@ -92,24 +75,14 @@ struct bucket_table {
		struct rhash_head __rcu *buckets[] ____cacheline_aligned_in_smp;
		};

		static inline unsigned long rht_marker(const struct rhashtable *ht, u32 hash)
		{
		return NULLS_MARKER(ht->p.nulls_base + hash);
		}

		#define INIT_RHT_NULLS_HEAD(ptr, ht, hash) \
		((ptr) = (typeof(ptr)) rht_marker(ht, hash))
		((ptr) = (typeof(ptr)) NULLS_MARKER(0))

		static inline bool rht_is_a_nulls(const struct rhash_head *ptr)
		{
		return ((unsigned long) ptr & 1);
		}

		static inline unsigned long rht_get_nulls_value(const struct rhash_head *ptr)
		{
		return ((unsigned long) ptr) >> 1;
		}

		static inline void rht_obj(const struct rhashtable ht,
		const struct rhash_head *he)
		{
		@@ -119,7 +92,7 @@ static inline void rht_obj(const struct rhashtable ht,
		static inline unsigned int rht_bucket_index(const struct bucket_table *tbl,
		unsigned int hash)
		{
		return (hash >> RHT_HASH_RESERVED_SPACE) & (tbl->size - 1);
		return hash & (tbl->size - 1);
		}

		static inline unsigned int rht_key_get_hash(struct rhashtable *ht,

lib/rhashtable.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -995,7 +995,6 @@ static u32 rhashtable_jhash2(const void *key, u32 length, u32 seed)
		* .key_offset = offsetof(struct test_obj, key),
		* .key_len = sizeof(int),
		* .hashfn = jhash,
		* .nulls_base = (1U << RHT_BASE_SHIFT),
		* };
		*
		* Configuration Example 2: Variable length keys
		@@ -1029,9 +1028,6 @@ int rhashtable_init(struct rhashtable *ht,
		(params->obj_hashfn && !params->obj_cmpfn))
		return -EINVAL;

		if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT))
		return -EINVAL;

		memset(ht, 0, sizeof(*ht));
		mutex_init(&ht->mutex);
		spin_lock_init(&ht->lock);
		@@ -1096,10 +1092,6 @@ int rhltable_init(struct rhltable hlt, const struct rhashtable_params params)
		{
		int err;

		/* No rhlist NULLs marking for now. */
		if (params->nulls_base)
		return -EINVAL;

		err = rhashtable_init(&hlt->ht, params);
		hlt->ht.rhlist = true;
		return err;

lib/test_rhashtable.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -83,7 +83,7 @@ static u32 my_hashfn(const void *data, u32 len, u32 seed)
		{
		const struct test_obj_rhl *obj = data;

		return (obj->value.id % 10) << RHT_HASH_RESERVED_SPACE;
		return (obj->value.id % 10);
		}

		static int my_cmpfn(struct rhashtable_compare_arg arg, const void obj)
		@@ -99,7 +99,6 @@ static struct rhashtable_params test_rht_params = {
		.key_offset = offsetof(struct test_obj, value),
		.key_len = sizeof(struct test_obj_val),
		.hashfn = jhash,
		.nulls_base = (3U << RHT_BASE_SHIFT),
		};

		static struct rhashtable_params test_rht_params_dup = {
		@@ -296,8 +295,6 @@ static int __init test_rhltable(unsigned int entries)
		if (!obj_in_table)
		goto out_free;

		/* nulls_base not supported in rhlist interface */
		test_rht_params.nulls_base = 0;
		err = rhltable_init(&rhlt, &test_rht_params);
		if (WARN_ON(err))
		goto out_free;

net/core/xdp.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -45,8 +45,8 @@ static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
		BUILD_BUG_ON(FIELD_SIZEOF(struct xdp_mem_allocator, mem.id)
		!= sizeof(u32));

		/* Use cyclic increasing ID as direct hash key, see rht_bucket_index */
		return key << RHT_HASH_RESERVED_SPACE;
		/* Use cyclic increasing ID as direct hash key */
		return key;
		}

		static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg,

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