[PATCH 26/29] mm: shrinker: make count and scan in shrinker debugfs lockless
From: Qi Zheng <hidden>
Date: 2023-06-22 09:06:11
Also in:
dm-devel, dri-devel, intel-gfx, linux-arm-msm, linux-bcache, linux-btrfs, linux-ext4, linux-fsdevel, linux-mm, linux-nfs, linux-xfs, lkml
Subsystem:
memory management, shrinker, the rest · Maintainers:
Andrew Morton, Dave Chinner, Linus Torvalds
Like global and memcg slab shrink, also make count and scan operations in memory shrinker debugfs lockless. The debugfs_remove_recursive() will wait for debugfs_file_put() to return, so there is no need to call rcu_read_lock() before calling shrinker_try_get(). Signed-off-by: Qi Zheng <redacted> --- mm/shrinker_debug.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c
index 3ab53fad8876..c18fa9b6b7f0 100644
--- a/mm/shrinker_debug.c
+++ b/mm/shrinker_debug.c@@ -55,8 +55,8 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v) if (!count_per_node) return -ENOMEM; - ret = down_read_killable(&shrinker_rwsem); - if (ret) { + ret = shrinker_try_get(shrinker); + if (!ret) { kfree(count_per_node); return ret; }
@@ -92,7 +92,7 @@ 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); + shrinker_put(shrinker); kfree(count_per_node); return ret;
@@ -146,8 +146,8 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file, return -EINVAL; } - ret = down_read_killable(&shrinker_rwsem); - if (ret) { + ret = shrinker_try_get(shrinker); + if (!ret) { mem_cgroup_put(memcg); return ret; }
@@ -159,7 +159,7 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file, shrinker->scan_objects(shrinker, &sc); - up_read(&shrinker_rwsem); + shrinker_put(shrinker); mem_cgroup_put(memcg); return size;
--
2.30.2