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);
34 static u64 parse_meminfo_line(const char *line)
38 if (sscanf(line, " %llu kB", &v) < 1)
43 static struct meminfo read_meminfo(void)
45 struct meminfo ret = { 0 };
51 f = fopen("/proc/meminfo", "r");
53 die("error opening /proc/meminfo: %m");
55 while ((len = getline(&line, &n, f)) != -1) {
56 if ((v = strcmp_prefix(line, "MemTotal:")))
57 ret.total = parse_meminfo_line(v);
59 if ((v = strcmp_prefix(line, "MemAvailable:")))
60 ret.available = parse_meminfo_line(v);
69 void run_shrinkers(void)
71 struct shrinker *shrinker;
75 /* Fast out if there are no shrinkers to run. */
76 if (list_empty(&shrinker_list))
79 info = read_meminfo();
80 want_shrink = (info.total >> 2) - info.available;
85 mutex_lock(&shrinker_lock);
86 list_for_each_entry(shrinker, &shrinker_list, list) {
87 struct shrink_control sc = {
88 .nr_to_scan = want_shrink >> PAGE_SHIFT
91 shrinker->scan_objects(shrinker, &sc);
93 mutex_unlock(&shrinker_lock);