1 mbcache: get rid of _e_hash_list_head
3 From: Andreas Gruenbacher <agruenba@redhat.com>
5 Get rid of field _e_hash_list_head in cache entries and add bit field
8 Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
9 Signed-off-by: Jan Kara <jack@suse.cz>
10 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
12 fs/mbcache.c | 41 ++++++++++-------------------------------
13 include/linux/mbcache.h | 8 ++------
14 2 files changed, 12 insertions(+), 37 deletions(-)
16 diff --git a/fs/mbcache.c b/fs/mbcache.c
17 index 4241b633f155..903be151dcfe 100644
20 @@ -45,27 +45,10 @@ static struct kmem_cache *mb_entry_cache;
21 static unsigned long mb_cache_shrink(struct mb_cache *cache,
22 unsigned int nr_to_scan);
24 -static inline bool mb_cache_entry_referenced(struct mb_cache_entry *entry)
25 +static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache,
28 - return entry->_e_hash_list_head & 1;
31 -static inline void mb_cache_entry_set_referenced(struct mb_cache_entry *entry)
33 - entry->_e_hash_list_head |= 1;
36 -static inline void mb_cache_entry_clear_referenced(
37 - struct mb_cache_entry *entry)
39 - entry->_e_hash_list_head &= ~1;
42 -static inline struct hlist_bl_head *mb_cache_entry_head(
43 - struct mb_cache_entry *entry)
45 - return (struct hlist_bl_head *)
46 - (entry->_e_hash_list_head & ~1);
47 + return &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
51 @@ -108,8 +91,7 @@ int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
52 atomic_set(&entry->e_refcnt, 1);
54 entry->e_block = block;
55 - head = &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
56 - entry->_e_hash_list_head = (unsigned long)head;
57 + head = mb_cache_entry_head(cache, key);
59 hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) {
60 if (dup->e_key == key && dup->e_block == block) {
61 @@ -146,10 +128,7 @@ static struct mb_cache_entry *__entry_find(struct mb_cache *cache,
62 struct hlist_bl_node *node;
63 struct hlist_bl_head *head;
66 - head = mb_cache_entry_head(entry);
68 - head = &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
69 + head = mb_cache_entry_head(cache, key);
71 if (entry && !hlist_bl_unhashed(&entry->e_hash_list))
72 node = entry->e_hash_list.next;
73 @@ -219,7 +198,7 @@ void mb_cache_entry_delete_block(struct mb_cache *cache, u32 key,
74 struct hlist_bl_head *head;
75 struct mb_cache_entry *entry;
77 - head = &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
78 + head = mb_cache_entry_head(cache, key);
80 hlist_bl_for_each_entry(entry, node, head, e_hash_list) {
81 if (entry->e_key == key && entry->e_block == block) {
82 @@ -250,7 +229,7 @@ EXPORT_SYMBOL(mb_cache_entry_delete_block);
83 void mb_cache_entry_touch(struct mb_cache *cache,
84 struct mb_cache_entry *entry)
86 - mb_cache_entry_set_referenced(entry);
87 + entry->e_referenced = 1;
89 EXPORT_SYMBOL(mb_cache_entry_touch);
91 @@ -275,8 +254,8 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache,
92 while (nr_to_scan-- && !list_empty(&cache->c_list)) {
93 entry = list_first_entry(&cache->c_list,
94 struct mb_cache_entry, e_list);
95 - if (mb_cache_entry_referenced(entry)) {
96 - mb_cache_entry_clear_referenced(entry);
97 + if (entry->e_referenced) {
98 + entry->e_referenced = 0;
99 list_move_tail(&cache->c_list, &entry->e_list);
102 @@ -287,7 +266,7 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache,
105 spin_unlock(&cache->c_list_lock);
106 - head = mb_cache_entry_head(entry);
107 + head = mb_cache_entry_head(cache, entry->e_key);
109 if (!hlist_bl_unhashed(&entry->e_hash_list)) {
110 hlist_bl_del_init(&entry->e_hash_list);
111 diff --git a/include/linux/mbcache.h b/include/linux/mbcache.h
112 index a74a1f3082fb..607e6968542e 100644
113 --- a/include/linux/mbcache.h
114 +++ b/include/linux/mbcache.h
115 @@ -12,18 +12,14 @@ struct mb_cache;
116 struct mb_cache_entry {
117 /* List of entries in cache - protected by cache->c_list_lock */
118 struct list_head e_list;
119 - /* Hash table list - protected by bitlock in e_hash_list_head */
120 + /* Hash table list - protected by hash chain bitlock */
121 struct hlist_bl_node e_hash_list;
123 /* Key in hash - stable during lifetime of the entry */
125 + u32 e_referenced:1;
126 /* Block number of hashed block - stable during lifetime of the entry */
129 - * Head of hash list (for list bit lock) - stable. Combined with
130 - * referenced bit of entry
132 - unsigned long _e_hash_list_head;
135 struct mb_cache *mb_cache_create(int bucket_bits);