4 #include <linux/list.h>
5 #include <linux/mutex.h>
6 #include <linux/shrinker.h>
8 #include "tools-util.h"
10 static LIST_HEAD(shrinker_list);
11 static DEFINE_MUTEX(shrinker_lock);
13 int register_shrinker(struct shrinker *shrinker)
15 mutex_lock(&shrinker_lock);
16 list_add_tail(&shrinker->list, &shrinker_list);
17 mutex_unlock(&shrinker_lock);
21 void unregister_shrinker(struct shrinker *shrinker)
23 mutex_lock(&shrinker_lock);
24 list_del(&shrinker->list);
25 mutex_unlock(&shrinker_lock);
33 static u64 parse_meminfo_line(const char *line)
37 if (sscanf(line, " %llu kB", &v) < 1)
42 static struct meminfo read_meminfo(void)
44 struct meminfo ret = { 0 };
50 f = fopen("/proc/meminfo", "r");
54 while ((len = getline(&line, &n, f)) != -1) {
55 if ((v = strcmp_prefix(line, "MemTotal:")))
56 ret.total = parse_meminfo_line(v);
58 if ((v = strcmp_prefix(line, "MemAvailable:")))
59 ret.available = parse_meminfo_line(v);
68 void run_shrinkers(void)
70 struct shrinker *shrinker;
74 /* Fast out if there are no shrinkers to run. */
75 if (list_empty(&shrinker_list))
78 info = read_meminfo();
80 if (info.total && info.available) {
81 want_shrink = (info.total >> 2) - info.available;
86 /* If we weren't able to read /proc/meminfo, we must be pretty
89 want_shrink = 8 << 20;
92 mutex_lock(&shrinker_lock);
93 list_for_each_entry(shrinker, &shrinker_list, list) {
94 struct shrink_control sc = {
95 .nr_to_scan = want_shrink >> PAGE_SHIFT
98 shrinker->scan_objects(shrinker, &sc);
100 mutex_unlock(&shrinker_lock);