2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/sbin/hammer/cache.c,v 1.5 2008/05/16 18:39:03 dillon Exp $
37 #include "hammer_util.h"
40 static int CacheMax = HAMMER_BUFSIZE * 1024;
41 static TAILQ_HEAD(, cache_info) CacheList = TAILQ_HEAD_INITIALIZER(CacheList);
44 hammer_parse_cache_size(const char *arg)
47 int size = strtol(arg, &ptr, 0);
61 /* bytes if no suffix */
68 UseReadAhead = strtol(ptr + 1, NULL, 0);
69 UseReadBehind = -UseReadAhead;
71 if (size < 1024 * 1024)
75 if (UseReadAhead * HAMMER_BUFSIZE / size / 16) {
76 UseReadAhead = size / 16 / HAMMER_BUFSIZE;
77 UseReadBehind = -UseReadAhead;
85 hammer_cache_add(struct cache_info *cache)
87 TAILQ_INSERT_HEAD(&CacheList, cache, entry);
88 CacheUse += HAMMER_BUFSIZE;
92 hammer_cache_del(struct cache_info *cache)
94 TAILQ_REMOVE(&CacheList, cache, entry);
95 CacheUse -= HAMMER_BUFSIZE;
99 hammer_cache_used(struct cache_info *cache)
101 TAILQ_REMOVE(&CacheList, cache, entry);
102 TAILQ_INSERT_TAIL(&CacheList, cache, entry);
106 hammer_cache_flush(void)
108 struct cache_info *cache;
109 struct cache_info *first = NULL;
112 if (CacheUse >= CacheMax) {
113 while ((cache = TAILQ_FIRST(&CacheList)) != NULL) {
115 break; /* seen this ref'd before */
120 hammer_cache_used(cache);
124 if (count >= (CacheUse / HAMMER_BUFSIZE)) {
125 CacheMax += HAMMER_BUFSIZE * 512;
131 rel_buffer((struct buffer_info*)cache);
133 if (CacheUse < CacheMax / 2)