nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

mm: shrinkers: make count and scan in shrinker debugfs lockless

Browse source 
Like global and memcg slab shrink, also use SRCU to make count and scan
operations in memory shrinker debugfs lockless.

Link: https://lkml.kernel.org/r/20230313112819.38938-6-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill Tkhai <tkhai@ya.ru>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christian König <christian.koenig@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Qi Zheng 2023-03-13 19:28:16 +08:00 committed by Andrew Morton
parent 475733dda5
commit 20cd1892fc
1 changed files with 8 additions and 17 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

25
mm/shrinker_debug.c
View file

@ -5,10 +5,12 @@
#include <linux/seq_file.h>
#include <linux/shrinker.h>
#include <linux/memcontrol.h>
#include <linux/srcu.h>
/* defined in vmscan.c */
extern struct rw_semaphore shrinker_rwsem;
extern struct list_head shrinker_list;
extern struct srcu_struct shrinker_srcu;
static DEFINE_IDA(shrinker_debugfs_ida);
static struct dentry *shrinker_debugfs_root;
@ -49,18 +51,13 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
struct mem_cgroup *memcg;
unsigned long total;
bool memcg_aware;
int ret, nid;
int ret = 0, nid, srcu_idx;
count_per_node = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
if (!count_per_node)
return -ENOMEM;
ret = down_read_killable(&shrinker_rwsem);
if (ret) {
kfree(count_per_node);
return ret;
}
rcu_read_lock();
srcu_idx = srcu_read_lock(&shrinker_srcu);
memcg_aware = shrinker->flags & SHRINKER_MEMCG_AWARE;
@ -91,8 +88,7 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v)
}
} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
rcu_read_unlock();
up_read(&shrinker_rwsem);
srcu_read_unlock(&shrinker_srcu, srcu_idx);
kfree(count_per_node);
return ret;
@ -115,9 +111,8 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
.gfp_mask = GFP_KERNEL,
};
struct mem_cgroup *memcg = NULL;
int nid;
int nid, srcu_idx;
char kbuf[72];
ssize_t ret;
read_len = size < (sizeof(kbuf) - 1) ? size : (sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, read_len))
@ -146,11 +141,7 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
return -EINVAL;
}
ret = down_read_killable(&shrinker_rwsem);
if (ret) {
mem_cgroup_put(memcg);
return ret;
}
srcu_idx = srcu_read_lock(&shrinker_srcu);
sc.nid = nid;
sc.memcg = memcg;
@ -159,7 +150,7 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file,
shrinker->scan_objects(shrinker, &sc);
up_read(&shrinker_rwsem);
srcu_read_unlock(&shrinker_srcu, srcu_idx);
mem_cgroup_put(memcg);
return size;