From mboxrd@z Thu Jan 1 00:00:00 1970 From: Herbert Xu Subject: [v2 PATCH 5/6] rhashtable: Add rehash counter to bucket_table Date: Sat, 14 Mar 2015 13:57:24 +1100 Message-ID: References: <20150314025339.GA10585@gondor.apana.org.au> To: David Miller , Thomas Graf , netdev@vger.kernel.org Return-path: Received: from ringil.hengli.com.au ([178.18.16.133]:36488 "EHLO ringil.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751884AbbCNC52 (ORCPT ); Fri, 13 Mar 2015 22:57:28 -0400 Sender: netdev-owner@vger.kernel.org List-ID: 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: Herbert Xu --- include/linux/rhashtable.h | 4 +++- lib/rhashtable.c | 1 + lib/test_rhashtable.c | 2 +- 3 files changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index a0abddd..ed7562a 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -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; diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 36fb091..ff4ea17 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -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); } diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c index 67c7593..16974fd 100644 --- a/lib/test_rhashtable.c +++ b/lib/test_rhashtable.c @@ -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++;