+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2006 Silicon Graphics, Inc.
* All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __CACHE_H__
#define __CACHE_H__
+/*
+ * initialisation flags
+ */
+/*
+ * xfs_db always writes changes immediately, and so we need to purge buffers
+ * when we get a buffer lookup mismatch due to reading the same block with a
+ * different buffer configuration.
+ */
+#define CACHE_MISCOMPARE_PURGE (1 << 0)
+
+/*
+ * cache object campare return values
+ */
+enum {
+ CACHE_HIT,
+ CACHE_MISS,
+ CACHE_PURGE,
+};
+
+#define HASH_CACHE_RATIO 8
+
+/*
+ * Cache priorities range from BASE to MAX.
+ *
+ * For prefetch support, the top half of the range starts at
+ * CACHE_PREFETCH_PRIORITY and everytime the buffer is fetched and is at or
+ * above this priority level, it is reduced to below this level (refer to
+ * libxfs_getbuf).
+ *
+ * If we have dirty nodes, we can't recycle them until they've been cleaned. To
+ * keep these out of the reclaimable lists (as there can be lots of them) give
+ * them their own priority that the shaker doesn't attempt to walk.
+ */
+
+#define CACHE_BASE_PRIORITY 0
+#define CACHE_PREFETCH_PRIORITY 8
+#define CACHE_MAX_PRIORITY 15
+#define CACHE_DIRTY_PRIORITY (CACHE_MAX_PRIORITY + 1)
+#define CACHE_NR_PRIORITIES CACHE_DIRTY_PRIORITY
+
/*
* Simple, generic implementation of a cache (arbitrary data).
* Provides a hash table with a capped number of cache entries.
*/
struct cache;
-struct cache_hash;
struct cache_node;
typedef void *cache_key_t;
+
typedef void (*cache_walk_t)(struct cache_node *);
-typedef struct cache_node * (*cache_node_alloc_t)(void);
+typedef struct cache_node * (*cache_node_alloc_t)(cache_key_t);
+typedef int (*cache_node_flush_t)(struct cache_node *);
typedef void (*cache_node_relse_t)(struct cache_node *);
-typedef unsigned int (*cache_node_hash_t)(cache_key_t, unsigned int);
+typedef unsigned int (*cache_node_hash_t)(cache_key_t, unsigned int,
+ unsigned int);
typedef int (*cache_node_compare_t)(struct cache_node *, cache_key_t);
+typedef unsigned int (*cache_bulk_relse_t)(struct cache *, struct list_head *);
struct cache_operations {
cache_node_hash_t hash;
cache_node_alloc_t alloc;
+ cache_node_flush_t flush;
cache_node_relse_t relse;
cache_node_compare_t compare;
+ cache_bulk_relse_t bulkrelse; /* optional */
+};
+
+struct cache_hash {
+ struct list_head ch_list; /* hash chain head */
+ unsigned int ch_count; /* hash chain length */
+ pthread_mutex_t ch_mutex; /* hash chain mutex */
+};
+
+struct cache_mru {
+ struct list_head cm_list; /* MRU head */
+ unsigned int cm_count; /* MRU length */
+ pthread_mutex_t cm_mutex; /* MRU lock */
+};
+
+struct cache_node {
+ struct list_head cn_hash; /* hash chain */
+ struct list_head cn_mru; /* MRU chain */
+ unsigned int cn_count; /* reference count */
+ unsigned int cn_hashidx; /* hash chain index */
+ int cn_priority; /* priority, -1 = free list */
+ int cn_old_priority;/* saved pre-dirty prio */
+ pthread_mutex_t cn_mutex; /* node mutex */
};
struct cache {
+ int c_flags; /* behavioural flags */
unsigned int c_maxcount; /* max cache nodes */
unsigned int c_count; /* count of nodes */
pthread_mutex_t c_mutex; /* node count mutex */
cache_node_hash_t hash; /* node hash function */
cache_node_alloc_t alloc; /* allocation function */
+ cache_node_flush_t flush; /* flush dirty data function */
cache_node_relse_t relse; /* memory free function */
cache_node_compare_t compare; /* comparison routine */
+ cache_bulk_relse_t bulkrelse; /* bulk release routine */
unsigned int c_hashsize; /* hash bucket count */
+ unsigned int c_hashshift; /* hash key shift */
struct cache_hash *c_hash; /* hash table buckets */
+ struct cache_mru c_mrus[CACHE_DIRTY_PRIORITY + 1];
+ unsigned long long c_misses; /* cache misses */
+ unsigned long long c_hits; /* cache hits */
+ unsigned int c_max; /* max nodes ever used */
};
-struct cache_hash {
- struct list_head ch_list; /* hash chain head */
- pthread_mutex_t ch_mutex; /* hash chain mutex */
-};
-
-struct cache_node {
- struct list_head cn_list; /* hash chain */
- unsigned int cn_count; /* reference count */
- pthread_mutex_t cn_mutex; /* refcount mutex */
-};
-
-struct cache *cache_init(unsigned int, struct cache_operations *);
+struct cache *cache_init(int, unsigned int, struct cache_operations *);
void cache_destroy(struct cache *);
void cache_walk(struct cache *, cache_walk_t);
void cache_purge(struct cache *);
+void cache_flush(struct cache *);
int cache_node_get(struct cache *, cache_key_t, struct cache_node **);
-void cache_node_put(struct cache_node *);
+void cache_node_put(struct cache *, struct cache_node *);
+void cache_node_set_priority(struct cache *, struct cache_node *, int);
+int cache_node_get_priority(struct cache_node *);
int cache_node_purge(struct cache *, cache_key_t, struct cache_node *);
+void cache_report(FILE *fp, const char *, struct cache *);
+int cache_overflowed(struct cache *);
#endif /* __CACHE_H__ */
projects / thirdparty / xfsprogs-dev.git / blobdiff