Commit 63d512d0 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

rhashtable: Add rehash counter to bucket_table 



This patch adds a rehash counter to bucket_table to indicate
the last bucket that has been rehashed.  This serves two purposes:

1. Any bucket that has been rehashed can never gain a new object.
2. If the rehash counter reaches the size of the table, the table
will forever remain empty.

This patch also downsizes bucket_table->size to an unsigned int
since we do not support sizes greater than 32 bits yet.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9d901bc0

include/linux/rhashtable.h

+3 −1
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ struct rhash_head { 
/**

 * struct bucket_table - Table of hash buckets

 * @size: Number of hash buckets

 * @rehash: Current bucket being rehashed

 * @hash_rnd: Random seed to fold into hash

 * @shift: Current size (1 << shift)

 * @locks_mask: Mask to apply before accessing locks[]
@@ -58,7 +59,8 @@ struct rhash_head { 
 * @buckets: size * hash buckets

 */

struct bucket_table {

	size_t			size;

	unsigned int		size;

	unsigned int		rehash;

	u32			hash_rnd;

	u32			shift;

	unsigned int		locks_mask;

lib/rhashtable.c

+1 −0
Original line number Diff line number Diff line
@@ -260,6 +260,7 @@ static void rhashtable_rehash_chain(struct rhashtable *ht, unsigned old_hash) 
	spin_lock_bh(old_bucket_lock);

	while (!rhashtable_rehash_one(ht, old_hash))

		;

	old_tbl->rehash++;

	spin_unlock_bh(old_bucket_lock);

}

lib/test_rhashtable.c

+1 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ static void test_bucket_stats(struct rhashtable *ht, bool quiet) 
		rcu_cnt = cnt = 0;



		if (!quiet)

			pr_info(" [%#4x/%zu]", i, tbl->size);

			pr_info(" [%#4x/%u]", i, tbl->size);



		rht_for_each_entry_rcu(obj, pos, tbl, i, node) {

			cnt++;

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