Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ob0-f174.google.com ([209.85.214.174]:43131 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751983Ab2HVC05 (ORCPT ); Tue, 21 Aug 2012 22:26:57 -0400 From: Sasha Levin To: torvalds@linux-foundation.org Cc: tj@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, paul.gortmaker@windriver.com, davem@davemloft.net, rostedt@goodmis.org, mingo@elte.hu, ebiederm@xmission.com, aarcange@redhat.com, ericvh@gmail.com, netdev@vger.kernel.org, josh@joshtriplett.org, eric.dumazet@gmail.com, mathieu.desnoyers@efficios.com, axboe@kernel.dk, agk@redhat.com, dm-devel@redhat.com, neilb@suse.de, ccaulfie@redhat.com, teigland@redhat.com, Trond.Myklebust@netapp.com, bfields@fieldses.org, fweisbec@gmail.com, jesse@nicira.com, venkat.x.venkatsubra@oracle.com, ejt@redhat.com, snitzer@redhat.com, edumazet@google.com, linux-nfs@vger.kernel.org, dev@openvswitch.org, rds-devel@oss.oracle.com, lw@cn.fujitsu.com, Sasha Levin Subject: [PATCH v3 01/17] hashtable: introduce a small and naive hashtable Date: Wed, 22 Aug 2012 04:26:56 +0200 Message-Id: <1345602432-27673-2-git-send-email-levinsasha928@gmail.com> In-Reply-To: <1345602432-27673-1-git-send-email-levinsasha928@gmail.com> References: <1345602432-27673-1-git-send-email-levinsasha928@gmail.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: This hashtable implementation is using hlist buckets to provide a simple hashtable to prevent it from getting reimplemented all over the kernel. Signed-off-by: Sasha Levin --- include/linux/hashtable.h | 291 +++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 291 insertions(+), 0 deletions(-) create mode 100644 include/linux/hashtable.h diff --git a/include/linux/hashtable.h b/include/linux/hashtable.h new file mode 100644 index 0000000..d2d6ed0 --- /dev/null +++ b/include/linux/hashtable.h @@ -0,0 +1,291 @@ +/* + * Hash table implementation + * (C) 2012 Sasha Levin + */ + +#ifndef _LINUX_HASHTABLE_H +#define _LINUX_HASHTABLE_H + +#include +#include +#include +#include +#include + +#define DEFINE_HASHTABLE(name, bits) \ + struct hlist_head name[HASH_SIZE(bits)]; + +#define HASH_SIZE(bits) (1 << (bits)) +#define HASH_BITS(name) (ilog2(ARRAY_SIZE(name))) +#define HASH_REQUIRED_SIZE(bits) (sizeof(struct hlist_head) * HASH_SIZE(bits)) + +/* Use hash_32 when possible to allow for fast 32bit hashing in 64bit kernels. */ +#define hash_min(val, bits) ((sizeof(val)==4) ? hash_32((val), (bits)) : hash_long((val), (bits))) + +/** + * hash_init_size - initialize a hash table + * @hashtable: hashtable to be initialized + * @bits: bit count of hashing function + * + * Initializes a hash table with 2**bits buckets. + */ +static inline void hash_init_size(struct hlist_head *hashtable, int bits) +{ + int i; + + for (i = 0; i < HASH_SIZE(bits); i++) + INIT_HLIST_HEAD(hashtable + i); +} + +/** + * hash_init - initialize a hash table + * @hashtable: hashtable to be initialized + * + * Calculates the size of the hashtable from the given parameter, otherwise + * same as hash_init_size. + */ +#define hash_init(name) hash_init_size(name, HASH_BITS(name)) + +/** + * hash_add_size - add an object to a hashtable + * @hashtable: hashtable to add to + * @bits: bit count used for hashing + * @node: the &struct hlist_node of the object to be added + * @key: the key of the object to be added + */ +#define hash_add_size(hashtable, bits, node, key) \ + hlist_add_head(node, &hashtable[hash_min(key, bits)]); + +/** + * hash_add - add an object to a hashtable + * @hashtable: hashtable to add to + * @node: the &struct hlist_node of the object to be added + * @key: the key of the object to be added + */ +#define hash_add(hashtable, node, key) \ + hash_add_size(hashtable, HASH_BITS(hashtable), node, key) + +/** + * hash_add_rcu_size - add an object to a rcu enabled hashtable + * @hashtable: hashtable to add to + * @bits: bit count used for hashing + * @node: the &struct hlist_node of the object to be added + * @key: the key of the object to be added + */ +#define hash_add_rcu_size(hashtable, bits, node, key) \ + hlist_add_head_rcu(node, &hashtable[hash_min(key, bits)]); + +/** + * hash_add_rcu - add an object to a rcu enabled hashtable + * @hashtable: hashtable to add to + * @node: the &struct hlist_node of the object to be added + * @key: the key of the object to be added + */ +#define hash_add_rcu(hashtable, node, key) \ + hash_add_rcu_size(hashtable, HASH_BITS(hashtable), node, key) + +/** + * hash_hashed - check whether an object is in any hashtable + * @node: the &struct hlist_node of the object to be checked + */ +#define hash_hashed(node) (!hlist_unhashed(node)) + +/** + * hash_empty_size - check whether a hashtable is empty + * @hashtable: hashtable to check + * @bits: bit count used for hashing + */ +static inline bool hash_empty_size(struct hlist_head *hashtable, int bits) +{ + int i; + + for (i = 0; i < HASH_SIZE(bits); i++) + if (!hlist_empty(&hashtable[i])) + return false; + + return true; +} + +/** + * hash_empty - check whether a hashtable is empty + * @hashtable: hashtable to check + */ +#define hash_empty(name) hash_empty_size(name, HASH_BITS(name)) + +/** + * hash_del - remove an object from a hashtable + * @node: &struct hlist_node of the object to remove + */ +static inline void hash_del(struct hlist_node *node) +{ + hlist_del_init(node); +} + +/** + * hash_del_rcu - remove an object from a rcu enabled hashtable + * @node: &struct hlist_node of the object to remove + */ +static inline void hash_del_rcu(struct hlist_node *node) +{ + hlist_del_init_rcu(node); +} + +/** + * hash_for_each_size - iterate over a hashtable + * @name: hashtable to iterate + * @bits: bit count of hashing function of the hashtable + * @bkt: integer to use as bucket loop cursor + * @node: the &struct list_head to use as a loop cursor for each entry + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_size(name, bits, bkt, node, obj, member) \ + for (bkt = 0; bkt < HASH_SIZE(bits); bkt++) \ + hlist_for_each_entry(obj, node, &name[bkt], member) + +/** + * hash_for_each - iterate over a hashtable + * @name: hashtable to iterate + * @bkt: integer to use as bucket loop cursor + * @node: the &struct list_head to use as a loop cursor for each entry + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each(name, bkt, node, obj, member) \ + hash_for_each_size(name, HASH_BITS(name), bkt, node, obj, member) + +/** + * hash_for_each_rcu_size - iterate over a rcu enabled hashtable + * @name: hashtable to iterate + * @bits: bit count of hashing function of the hashtable + * @bkt: integer to use as bucket loop cursor + * @node: the &struct list_head to use as a loop cursor for each entry + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_rcu_size(name, bits, bkt, node, obj, member) \ + for (bkt = 0; bkt < HASH_SIZE(bits); bkt++) \ + hlist_for_each_entry_rcu(obj, node, &name[bkt], member) + +/** + * hash_for_each_rcu - iterate over a rcu enabled hashtable + * @name: hashtable to iterate + * @bkt: integer to use as bucket loop cursor + * @node: the &struct list_head to use as a loop cursor for each entry + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_rcu(name, bkt, node, obj, member) \ + hash_for_each_rcu_size(name, HASH_BITS(name), bkt, node, obj, member) + +/** + * hash_for_each_safe_size - iterate over a hashtable safe against removal of + * hash entry + * @name: hashtable to iterate + * @bkt: integer to use as bucket loop cursor + * @node: the &struct list_head to use as a loop cursor for each entry + * @tmp: another &struct hlist_node to use as temporary storage + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_safe_size(name, bits, bkt, node, tmp, obj, member) \ + for (bkt = 0; bkt < HASH_SIZE(bits); bkt++) \ + hlist_for_each_entry_safe(obj, node, tmp, &name[bkt], member) + +/** + * hash_for_each_safe_size - iterate over a hashtable safe against removal of + * hash entry + * @name: hashtable to iterate + * @bkt: integer to use as bucket loop cursor + * @node: the &struct list_head to use as a loop cursor for each entry + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_safe(name, bkt, node, tmp, obj, member) \ + hash_for_each_safe_size(name, HASH_BITS(name), bkt, node, \ + tmp, obj, member) + +/** + * hash_for_each_possible - iterate over all possible objects hasing to the + * same bucket + * @name: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @bits: bit count of hashing function of the hashtable + * @node: the &struct list_head to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_size(name, obj, bits, node, member, key) \ + hlist_for_each_entry(obj, node, &name[hash_min(key, bits)], member) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * @name: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @bits: bit count of hashing function of the hashtable + * @node: the &struct list_head to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible(name, obj, node, member, key) \ + hash_for_each_possible_size(name, obj, HASH_BITS(name), node, member, key) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * in a rcu enabled hashtable + * @name: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @bits: bit count of hashing function of the hashtable + * @node: the &struct list_head to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_rcu_size(name, obj, bits, node, member, key) \ + hlist_for_each_entry_rcu(obj, node, &name[hash_min(key, bits)], member) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * in a rcu enabled hashtable + * @name: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @node: the &struct list_head to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_rcu(name, obj, node, member, key) \ + hash_for_each_possible_rcu_size(name, obj, HASH_BITS(name), \ + node, member, key) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * safe against removal of hash entry + * @name: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @bits: bit count of hashing function of the hashtable + * @node: the &struct list_head to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_safe_size(name, obj, bits, node, tmp, member, key)\ + hlist_for_each_entry_safe(obj, node, tmp, \ + &name[hash_min(key, bits)], member) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * safe against removal of hash entry + * @name: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @node: the &struct list_head to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_safe(name, obj, node, tmp, member, key) \ + hash_for_each_possible_safe_size(name, obj, HASH_BITS(name), \ + node, tmp, member, key) + +#endif -- 1.7.8.6