15035ebc6SRoman Gushchin // SPDX-License-Identifier: GPL-2.0
25035ebc6SRoman Gushchin #include <linux/idr.h>
35035ebc6SRoman Gushchin #include <linux/slab.h>
45035ebc6SRoman Gushchin #include <linux/debugfs.h>
55035ebc6SRoman Gushchin #include <linux/seq_file.h>
65035ebc6SRoman Gushchin #include <linux/shrinker.h>
75035ebc6SRoman Gushchin #include <linux/memcontrol.h>
85035ebc6SRoman Gushchin
95035ebc6SRoman Gushchin /* defined in vmscan.c */
1047a7c01cSQi Zheng extern struct rw_semaphore shrinker_rwsem;
115035ebc6SRoman Gushchin extern struct list_head shrinker_list;
125035ebc6SRoman Gushchin
135035ebc6SRoman Gushchin static DEFINE_IDA(shrinker_debugfs_ida);
145035ebc6SRoman Gushchin static struct dentry *shrinker_debugfs_root;
155035ebc6SRoman Gushchin
shrinker_count_objects(struct shrinker * shrinker,struct mem_cgroup * memcg,unsigned long * count_per_node)165035ebc6SRoman Gushchin static unsigned long shrinker_count_objects(struct shrinker *shrinker,
175035ebc6SRoman Gushchin struct mem_cgroup *memcg,
185035ebc6SRoman Gushchin unsigned long *count_per_node)
195035ebc6SRoman Gushchin {
205035ebc6SRoman Gushchin unsigned long nr, total = 0;
215035ebc6SRoman Gushchin int nid;
225035ebc6SRoman Gushchin
235035ebc6SRoman Gushchin for_each_node(nid) {
245035ebc6SRoman Gushchin if (nid == 0 || (shrinker->flags & SHRINKER_NUMA_AWARE)) {
255035ebc6SRoman Gushchin struct shrink_control sc = {
265035ebc6SRoman Gushchin .gfp_mask = GFP_KERNEL,
275035ebc6SRoman Gushchin .nid = nid,
285035ebc6SRoman Gushchin .memcg = memcg,
295035ebc6SRoman Gushchin };
305035ebc6SRoman Gushchin
315035ebc6SRoman Gushchin nr = shrinker->count_objects(shrinker, &sc);
325035ebc6SRoman Gushchin if (nr == SHRINK_EMPTY)
335035ebc6SRoman Gushchin nr = 0;
345035ebc6SRoman Gushchin } else {
355035ebc6SRoman Gushchin nr = 0;
365035ebc6SRoman Gushchin }
375035ebc6SRoman Gushchin
385035ebc6SRoman Gushchin count_per_node[nid] = nr;
395035ebc6SRoman Gushchin total += nr;
405035ebc6SRoman Gushchin }
415035ebc6SRoman Gushchin
425035ebc6SRoman Gushchin return total;
435035ebc6SRoman Gushchin }
445035ebc6SRoman Gushchin
shrinker_debugfs_count_show(struct seq_file * m,void * v)455035ebc6SRoman Gushchin static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
465035ebc6SRoman Gushchin {
475035ebc6SRoman Gushchin struct shrinker *shrinker = m->private;
485035ebc6SRoman Gushchin unsigned long *count_per_node;
495035ebc6SRoman Gushchin struct mem_cgroup *memcg;
505035ebc6SRoman Gushchin unsigned long total;
515035ebc6SRoman Gushchin bool memcg_aware;
52*1a554eccSQi Zheng int ret, nid;
535035ebc6SRoman Gushchin
545035ebc6SRoman Gushchin count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
555035ebc6SRoman Gushchin if (!count_per_node)
565035ebc6SRoman Gushchin return -ENOMEM;
575035ebc6SRoman Gushchin
58*1a554eccSQi Zheng ret = down_read_killable(&shrinker_rwsem);
59*1a554eccSQi Zheng if (ret) {
60*1a554eccSQi Zheng kfree(count_per_node);
61*1a554eccSQi Zheng return ret;
62*1a554eccSQi Zheng }
63*1a554eccSQi Zheng rcu_read_lock();
645035ebc6SRoman Gushchin
655035ebc6SRoman Gushchin memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
665035ebc6SRoman Gushchin
675035ebc6SRoman Gushchin memcg = mem_cgroup_iter(NULL, NULL, NULL);
685035ebc6SRoman Gushchin do {
695035ebc6SRoman Gushchin if (memcg && !mem_cgroup_online(memcg))
705035ebc6SRoman Gushchin continue;
715035ebc6SRoman Gushchin
725035ebc6SRoman Gushchin total = shrinker_count_objects(shrinker,
735035ebc6SRoman Gushchin memcg_aware ? memcg : NULL,
745035ebc6SRoman Gushchin count_per_node);
755035ebc6SRoman Gushchin if (total) {
765035ebc6SRoman Gushchin seq_printf(m, "%lu", mem_cgroup_ino(memcg));
775035ebc6SRoman Gushchin for_each_node(nid)
785035ebc6SRoman Gushchin seq_printf(m, " %lu", count_per_node[nid]);
795035ebc6SRoman Gushchin seq_putc(m, '\n');
805035ebc6SRoman Gushchin }
815035ebc6SRoman Gushchin
825035ebc6SRoman Gushchin if (!memcg_aware) {
835035ebc6SRoman Gushchin mem_cgroup_iter_break(NULL, memcg);
845035ebc6SRoman Gushchin break;
855035ebc6SRoman Gushchin }
865035ebc6SRoman Gushchin
875035ebc6SRoman Gushchin if (signal_pending(current)) {
885035ebc6SRoman Gushchin mem_cgroup_iter_break(NULL, memcg);
895035ebc6SRoman Gushchin ret = -EINTR;
905035ebc6SRoman Gushchin break;
915035ebc6SRoman Gushchin }
925035ebc6SRoman Gushchin } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
935035ebc6SRoman Gushchin
94*1a554eccSQi Zheng rcu_read_unlock();
95*1a554eccSQi Zheng up_read(&shrinker_rwsem);
965035ebc6SRoman Gushchin
975035ebc6SRoman Gushchin kfree(count_per_node);
985035ebc6SRoman Gushchin return ret;
995035ebc6SRoman Gushchin }
1005035ebc6SRoman Gushchin DEFINE_SHOW_ATTRIBUTE(shrinker_debugfs_count);
1015035ebc6SRoman Gushchin
shrinker_debugfs_scan_open(struct inode * inode,struct file * file)102bbf535fdSRoman Gushchin static int shrinker_debugfs_scan_open(struct inode *inode, struct file *file)
103bbf535fdSRoman Gushchin {
104bbf535fdSRoman Gushchin file->private_data = inode->i_private;
105bbf535fdSRoman Gushchin return nonseekable_open(inode, file);
106bbf535fdSRoman Gushchin }
107bbf535fdSRoman Gushchin
shrinker_debugfs_scan_write(struct file * file,const char __user * buf,size_t size,loff_t * pos)108bbf535fdSRoman Gushchin static ssize_t shrinker_debugfs_scan_write(struct file *file,
109bbf535fdSRoman Gushchin const char __user *buf,
110bbf535fdSRoman Gushchin size_t size, loff_t *pos)
111bbf535fdSRoman Gushchin {
112bbf535fdSRoman Gushchin struct shrinker *shrinker = file->private_data;
113bbf535fdSRoman Gushchin unsigned long nr_to_scan = 0, ino, read_len;
114bbf535fdSRoman Gushchin struct shrink_control sc = {
115bbf535fdSRoman Gushchin .gfp_mask = GFP_KERNEL,
116bbf535fdSRoman Gushchin };
117bbf535fdSRoman Gushchin struct mem_cgroup *memcg = NULL;
118*1a554eccSQi Zheng int nid;
119bbf535fdSRoman Gushchin char kbuf[72];
120*1a554eccSQi Zheng ssize_t ret;
121bbf535fdSRoman Gushchin
122bbf535fdSRoman Gushchin read_len = size < (sizeof(kbuf) - 1) ? size : (sizeof(kbuf) - 1);
123bbf535fdSRoman Gushchin if (copy_from_user(kbuf, buf, read_len))
124bbf535fdSRoman Gushchin return -EFAULT;
125bbf535fdSRoman Gushchin kbuf[read_len] = '\0';
126bbf535fdSRoman Gushchin
127bbf535fdSRoman Gushchin if (sscanf(kbuf, "%lu %d %lu", &ino, &nid, &nr_to_scan) != 3)
128bbf535fdSRoman Gushchin return -EINVAL;
129bbf535fdSRoman Gushchin
130bbf535fdSRoman Gushchin if (nid < 0 || nid >= nr_node_ids)
131bbf535fdSRoman Gushchin return -EINVAL;
132bbf535fdSRoman Gushchin
133bbf535fdSRoman Gushchin if (nr_to_scan == 0)
134bbf535fdSRoman Gushchin return size;
135bbf535fdSRoman Gushchin
136bbf535fdSRoman Gushchin if (shrinker->flags & SHRINKER_MEMCG_AWARE) {
137bbf535fdSRoman Gushchin memcg = mem_cgroup_get_from_ino(ino);
138bbf535fdSRoman Gushchin if (!memcg || IS_ERR(memcg))
139bbf535fdSRoman Gushchin return -ENOENT;
140bbf535fdSRoman Gushchin
141bbf535fdSRoman Gushchin if (!mem_cgroup_online(memcg)) {
142bbf535fdSRoman Gushchin mem_cgroup_put(memcg);
143bbf535fdSRoman Gushchin return -ENOENT;
144bbf535fdSRoman Gushchin }
145bbf535fdSRoman Gushchin } else if (ino != 0) {
146bbf535fdSRoman Gushchin return -EINVAL;
147bbf535fdSRoman Gushchin }
148bbf535fdSRoman Gushchin
149*1a554eccSQi Zheng ret = down_read_killable(&shrinker_rwsem);
150*1a554eccSQi Zheng if (ret) {
151*1a554eccSQi Zheng mem_cgroup_put(memcg);
152*1a554eccSQi Zheng return ret;
153*1a554eccSQi Zheng }
154bbf535fdSRoman Gushchin
155bbf535fdSRoman Gushchin sc.nid = nid;
156bbf535fdSRoman Gushchin sc.memcg = memcg;
157bbf535fdSRoman Gushchin sc.nr_to_scan = nr_to_scan;
158bbf535fdSRoman Gushchin sc.nr_scanned = nr_to_scan;
159bbf535fdSRoman Gushchin
160bbf535fdSRoman Gushchin shrinker->scan_objects(shrinker, &sc);
161bbf535fdSRoman Gushchin
162*1a554eccSQi Zheng up_read(&shrinker_rwsem);
163bbf535fdSRoman Gushchin mem_cgroup_put(memcg);
164bbf535fdSRoman Gushchin
165bbf535fdSRoman Gushchin return size;
166bbf535fdSRoman Gushchin }
167bbf535fdSRoman Gushchin
168bbf535fdSRoman Gushchin static const struct file_operations shrinker_debugfs_scan_fops = {
169bbf535fdSRoman Gushchin .owner = THIS_MODULE,
170bbf535fdSRoman Gushchin .open = shrinker_debugfs_scan_open,
171bbf535fdSRoman Gushchin .write = shrinker_debugfs_scan_write,
172bbf535fdSRoman Gushchin };
173bbf535fdSRoman Gushchin
shrinker_debugfs_add(struct shrinker * shrinker)1745035ebc6SRoman Gushchin int shrinker_debugfs_add(struct shrinker *shrinker)
1755035ebc6SRoman Gushchin {
1765035ebc6SRoman Gushchin struct dentry *entry;
177e33c267aSRoman Gushchin char buf[128];
1785035ebc6SRoman Gushchin int id;
1795035ebc6SRoman Gushchin
18047a7c01cSQi Zheng lockdep_assert_held(&shrinker_rwsem);
1815035ebc6SRoman Gushchin
1825035ebc6SRoman Gushchin /* debugfs isn't initialized yet, add debugfs entries later. */
1835035ebc6SRoman Gushchin if (!shrinker_debugfs_root)
1845035ebc6SRoman Gushchin return 0;
1855035ebc6SRoman Gushchin
1865035ebc6SRoman Gushchin id = ida_alloc(&shrinker_debugfs_ida, GFP_KERNEL);
1875035ebc6SRoman Gushchin if (id < 0)
1885035ebc6SRoman Gushchin return id;
1895035ebc6SRoman Gushchin shrinker->debugfs_id = id;
1905035ebc6SRoman Gushchin
191e33c267aSRoman Gushchin snprintf(buf, sizeof(buf), "%s-%d", shrinker->name, id);
1925035ebc6SRoman Gushchin
1935035ebc6SRoman Gushchin /* create debugfs entry */
1945035ebc6SRoman Gushchin entry = debugfs_create_dir(buf, shrinker_debugfs_root);
1955035ebc6SRoman Gushchin if (IS_ERR(entry)) {
1965035ebc6SRoman Gushchin ida_free(&shrinker_debugfs_ida, id);
1975035ebc6SRoman Gushchin return PTR_ERR(entry);
1985035ebc6SRoman Gushchin }
1995035ebc6SRoman Gushchin shrinker->debugfs_entry = entry;
2005035ebc6SRoman Gushchin
2012124f79dSJohn Keeping debugfs_create_file("count", 0440, entry, shrinker,
2025035ebc6SRoman Gushchin &shrinker_debugfs_count_fops);
2032124f79dSJohn Keeping debugfs_create_file("scan", 0220, entry, shrinker,
204bbf535fdSRoman Gushchin &shrinker_debugfs_scan_fops);
2055035ebc6SRoman Gushchin return 0;
2065035ebc6SRoman Gushchin }
2075035ebc6SRoman Gushchin
shrinker_debugfs_rename(struct shrinker * shrinker,const char * fmt,...)208e33c267aSRoman Gushchin int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
209e33c267aSRoman Gushchin {
210e33c267aSRoman Gushchin struct dentry *entry;
211e33c267aSRoman Gushchin char buf[128];
212e33c267aSRoman Gushchin const char *new, *old;
213e33c267aSRoman Gushchin va_list ap;
214e33c267aSRoman Gushchin int ret = 0;
215e33c267aSRoman Gushchin
216e33c267aSRoman Gushchin va_start(ap, fmt);
217e33c267aSRoman Gushchin new = kvasprintf_const(GFP_KERNEL, fmt, ap);
218e33c267aSRoman Gushchin va_end(ap);
219e33c267aSRoman Gushchin
220e33c267aSRoman Gushchin if (!new)
221e33c267aSRoman Gushchin return -ENOMEM;
222e33c267aSRoman Gushchin
22347a7c01cSQi Zheng down_write(&shrinker_rwsem);
224e33c267aSRoman Gushchin
225e33c267aSRoman Gushchin old = shrinker->name;
226e33c267aSRoman Gushchin shrinker->name = new;
227e33c267aSRoman Gushchin
228e33c267aSRoman Gushchin if (shrinker->debugfs_entry) {
229e33c267aSRoman Gushchin snprintf(buf, sizeof(buf), "%s-%d", shrinker->name,
230e33c267aSRoman Gushchin shrinker->debugfs_id);
231e33c267aSRoman Gushchin
232e33c267aSRoman Gushchin entry = debugfs_rename(shrinker_debugfs_root,
233e33c267aSRoman Gushchin shrinker->debugfs_entry,
234e33c267aSRoman Gushchin shrinker_debugfs_root, buf);
235e33c267aSRoman Gushchin if (IS_ERR(entry))
236e33c267aSRoman Gushchin ret = PTR_ERR(entry);
237e33c267aSRoman Gushchin else
238e33c267aSRoman Gushchin shrinker->debugfs_entry = entry;
239e33c267aSRoman Gushchin }
240e33c267aSRoman Gushchin
24147a7c01cSQi Zheng up_write(&shrinker_rwsem);
242e33c267aSRoman Gushchin
243e33c267aSRoman Gushchin kfree_const(old);
244e33c267aSRoman Gushchin
245e33c267aSRoman Gushchin return ret;
246e33c267aSRoman Gushchin }
247e33c267aSRoman Gushchin EXPORT_SYMBOL(shrinker_debugfs_rename);
248e33c267aSRoman Gushchin
shrinker_debugfs_detach(struct shrinker * shrinker,int * debugfs_id)24926e239b3SJoan Bruguera Micó struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker,
25026e239b3SJoan Bruguera Micó int *debugfs_id)
2515035ebc6SRoman Gushchin {
252badc28d4SQi Zheng struct dentry *entry = shrinker->debugfs_entry;
253badc28d4SQi Zheng
25447a7c01cSQi Zheng lockdep_assert_held(&shrinker_rwsem);
2555035ebc6SRoman Gushchin
256e33c267aSRoman Gushchin kfree_const(shrinker->name);
25714773bfaSTetsuo Handa shrinker->name = NULL;
258e33c267aSRoman Gushchin
25926e239b3SJoan Bruguera Micó *debugfs_id = entry ? shrinker->debugfs_id : -1;
260badc28d4SQi Zheng shrinker->debugfs_entry = NULL;
261badc28d4SQi Zheng
262badc28d4SQi Zheng return entry;
2635035ebc6SRoman Gushchin }
2645035ebc6SRoman Gushchin
shrinker_debugfs_remove(struct dentry * debugfs_entry,int debugfs_id)26526e239b3SJoan Bruguera Micó void shrinker_debugfs_remove(struct dentry *debugfs_entry, int debugfs_id)
26626e239b3SJoan Bruguera Micó {
26726e239b3SJoan Bruguera Micó debugfs_remove_recursive(debugfs_entry);
26826e239b3SJoan Bruguera Micó ida_free(&shrinker_debugfs_ida, debugfs_id);
26926e239b3SJoan Bruguera Micó }
27026e239b3SJoan Bruguera Micó
shrinker_debugfs_init(void)2715035ebc6SRoman Gushchin static int __init shrinker_debugfs_init(void)
2725035ebc6SRoman Gushchin {
2735035ebc6SRoman Gushchin struct shrinker *shrinker;
2745035ebc6SRoman Gushchin struct dentry *dentry;
2755035ebc6SRoman Gushchin int ret = 0;
2765035ebc6SRoman Gushchin
2775035ebc6SRoman Gushchin dentry = debugfs_create_dir("shrinker", NULL);
2785035ebc6SRoman Gushchin if (IS_ERR(dentry))
2795035ebc6SRoman Gushchin return PTR_ERR(dentry);
2805035ebc6SRoman Gushchin shrinker_debugfs_root = dentry;
2815035ebc6SRoman Gushchin
2825035ebc6SRoman Gushchin /* Create debugfs entries for shrinkers registered at boot */
28347a7c01cSQi Zheng down_write(&shrinker_rwsem);
2845035ebc6SRoman Gushchin list_for_each_entry(shrinker, &shrinker_list, list)
2855035ebc6SRoman Gushchin if (!shrinker->debugfs_entry) {
2865035ebc6SRoman Gushchin ret = shrinker_debugfs_add(shrinker);
2875035ebc6SRoman Gushchin if (ret)
2885035ebc6SRoman Gushchin break;
2895035ebc6SRoman Gushchin }
29047a7c01cSQi Zheng up_write(&shrinker_rwsem);
2915035ebc6SRoman Gushchin
2925035ebc6SRoman Gushchin return ret;
2935035ebc6SRoman Gushchin }
2945035ebc6SRoman Gushchin late_initcall(shrinker_debugfs_init);
295