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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271// SPDX-License-Identifier: GPL-2.0#include <linux/idr.h>#include <linux/slab.h>#include <linux/debugfs.h>#include <linux/seq_file.h>#include <linux/shrinker.h>#include <linux/memcontrol.h>
#include "internal.h"
/* defined in vmscan.c */extern struct mutex shrinker_mutex;extern struct list_head shrinker_list;
static DEFINE_IDA(shrinker_debugfs_ida);static struct dentry *shrinker_debugfs_root;
static unsigned long shrinker_count_objects(struct shrinker *shrinker, struct mem_cgroup *memcg, unsigned long *count_per_node){ unsigned long nr, total = 0; int nid;
for_each_node(nid) { if (nid == 0 || (shrinker->flags & SHRINKER_NUMA_AWARE)) { struct shrink_control sc = { .gfp_mask = GFP_KERNEL, .nid = nid, .memcg = memcg, };
nr = shrinker->count_objects(shrinker, &sc); if (nr == SHRINK_EMPTY) nr = 0; } else { nr = 0; }
count_per_node[nid] = nr; total += nr; }
return total;}
static int shrinker_debugfs_count_show(struct seq_file *m, void *v){ struct shrinker *shrinker = m->private; unsigned long *count_per_node; struct mem_cgroup *memcg; unsigned long total; bool memcg_aware; int ret = 0, nid;
count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL); if (!count_per_node) return -ENOMEM;
memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
memcg = mem_cgroup_iter(NULL, NULL, NULL); do { if (memcg && !mem_cgroup_online(memcg)) continue;
total = shrinker_count_objects(shrinker, memcg_aware ? memcg : NULL, count_per_node); if (total) { seq_printf(m, "%llu", mem_cgroup_id(memcg)); for_each_node(nid) seq_printf(m, " %lu", count_per_node[nid]); seq_putc(m, '\n'); }
if (!memcg_aware) { mem_cgroup_iter_break(NULL, memcg); break; }
if (signal_pending(current)) { mem_cgroup_iter_break(NULL, memcg); ret = -EINTR; break; } } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
kfree(count_per_node); return ret;}DEFINE_SHOW_ATTRIBUTE(shrinker_debugfs_count);
static int shrinker_debugfs_scan_open(struct inode *inode, struct file *file){ file->private_data = inode->i_private; return nonseekable_open(inode, file);}
static ssize_t shrinker_debugfs_scan_write(struct file *file, const char __user *buf, size_t size, loff_t *pos){ struct shrinker *shrinker = file->private_data; unsigned long nr_to_scan = 0, read_len; u64 id; struct shrink_control sc = { .gfp_mask = GFP_KERNEL, }; struct mem_cgroup *memcg = NULL; int nid; char kbuf[72];
read_len = min(size, sizeof(kbuf) - 1); if (copy_from_user(kbuf, buf, read_len)) return -EFAULT; kbuf[read_len] = '\0';
if (sscanf(kbuf, "%llu %d %lu", &id, &nid, &nr_to_scan) != 3) return -EINVAL;
if (nid < 0 || nid >= nr_node_ids) return -EINVAL;
if (nr_to_scan == 0) return size;
if (shrinker->flags & SHRINKER_MEMCG_AWARE) { memcg = mem_cgroup_get_from_id(id); if (!memcg) return -ENOENT;
if (!mem_cgroup_online(memcg)) { mem_cgroup_put(memcg); return -ENOENT; } } else if (id != 0) { return -EINVAL; }
sc.nid = nid; sc.memcg = memcg; sc.nr_to_scan = nr_to_scan; sc.nr_scanned = nr_to_scan;
shrinker->scan_objects(shrinker, &sc);
mem_cgroup_put(memcg);
return size;}
static const struct file_operations shrinker_debugfs_scan_fops = { .owner = THIS_MODULE, .open = shrinker_debugfs_scan_open, .write = shrinker_debugfs_scan_write,};
int shrinker_debugfs_add(struct shrinker *shrinker){ struct dentry *entry; char buf[128]; int id;
lockdep_assert_held(&shrinker_mutex);
/* debugfs isn't initialized yet, add debugfs entries later. */ if (!shrinker_debugfs_root) return 0;
id = ida_alloc(&shrinker_debugfs_ida, GFP_KERNEL); if (id < 0) return id; shrinker->debugfs_id = id;
snprintf(buf, sizeof(buf), "%s-%d", shrinker->name, id);
/* create debugfs entry */ entry = debugfs_create_dir(buf, shrinker_debugfs_root); if (IS_ERR(entry)) { ida_free(&shrinker_debugfs_ida, id); return PTR_ERR(entry); } shrinker->debugfs_entry = entry;
if (shrinker->count_objects) debugfs_create_file("count", 0440, entry, shrinker, &shrinker_debugfs_count_fops); if (shrinker->scan_objects) debugfs_create_file("scan", 0220, entry, shrinker, &shrinker_debugfs_scan_fops); return 0;}
int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...){ const char *new, *old; va_list ap; int ret = 0;
va_start(ap, fmt); new = kvasprintf_const(GFP_KERNEL, fmt, ap); va_end(ap);
if (!new) return -ENOMEM;
mutex_lock(&shrinker_mutex);
old = shrinker->name; shrinker->name = new;
ret = debugfs_change_name(shrinker->debugfs_entry, "%s-%d", shrinker->name, shrinker->debugfs_id);
if (ret) { shrinker->name = old; kfree_const(new); } else { kfree_const(old); } mutex_unlock(&shrinker_mutex);
return ret;}EXPORT_SYMBOL(shrinker_debugfs_rename);
struct dentry *shrinker_debugfs_detach(struct shrinker *shrinker, int *debugfs_id){ struct dentry *entry = shrinker->debugfs_entry;
lockdep_assert_held(&shrinker_mutex);
*debugfs_id = entry ? shrinker->debugfs_id : -1; shrinker->debugfs_entry = NULL;
return entry;}
void shrinker_debugfs_remove(struct dentry *debugfs_entry, int debugfs_id){ debugfs_remove_recursive(debugfs_entry); ida_free(&shrinker_debugfs_ida, debugfs_id);}
static int __init shrinker_debugfs_init(void){ struct shrinker *shrinker; struct dentry *dentry; int ret = 0;
dentry = debugfs_create_dir("shrinker", NULL); if (IS_ERR(dentry)) return PTR_ERR(dentry); shrinker_debugfs_root = dentry;
/* Create debugfs entries for shrinkers registered at boot */ mutex_lock(&shrinker_mutex); list_for_each_entry(shrinker, &shrinker_list, list) if (!shrinker->debugfs_entry) { ret = shrinker_debugfs_add(shrinker); if (ret) break; } mutex_unlock(&shrinker_mutex);
return ret;}late_initcall(shrinker_debugfs_init);