Add a simple tool which prints a sorted list of shrinker lists
in the following format: (number of objects, shrinker name, cgroup).
Example:
$ ./memcg_shrinker.py -n 10
2090 sb-sysfs-26 /sys/fs/cgroup/system.slice
1809 sb-sysfs-26 /sys/fs/cgroup/system.slice/systemd-udevd.service
1044 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice/system-dbus\x2d:1.3\...
861 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice/system-dbus\x2d:1.3\...
804 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice
643 sb-btrfs:vda2-24 /sys/fs/cgroup/system.slice/firewalld.service
616 sb-cgroup2-30 /sys/fs/cgroup/init.scope
275 sb-sysfs-26 /
238 sb-proc-25 /sys/fs/cgroup/system.slice/systemd-journald.service
225 sb-proc-25 /sys/fs/cgroup/system.slice/abrtd.service
Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
---
tools/cgroup/memcg_shrinker.py | 71 ++++++++++++++++++++++++++++++++++
1 file changed, 71 insertions(+)
create mode 100755 tools/cgroup/memcg_shrinker.py
diff --git a/tools/cgroup/memcg_shrinker.py b/tools/cgroup/memcg_shrinker.py
new file mode 100755
index 000000000000..706ab27666a4
--- /dev/null
+++ b/tools/cgroup/memcg_shrinker.py
@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022 Roman Gushchin <roman.gushchin@xxxxxxxxx>
+# Copyright (C) 2022 Meta
+
+import os
+import argparse
+import sys
+
+
+def scan_cgroups(cgroup_root):
+ cgroups = {}
+
+ for root, subdirs, _ in os.walk(cgroup_root):
+ for cgroup in subdirs:
+ path = os.path.join(root, cgroup)
+ ino = os.stat(path).st_ino
+ cgroups[ino] = path
+
+ # (memcg ino, path)
+ return cgroups
+
+
+def scan_shrinkers(shrinker_debugfs):
+ shrinkers = []
+
+ for root, subdirs, _ in os.walk(shrinker_debugfs):
+ for shrinker in subdirs:
+ count_path = os.path.join(root, shrinker, "count")
+ with open(count_path) as f:
+ for line in f.readlines():
+ items = line.split(' ')
+ ino = int(items[0])
+ # (count, shrinker, memcg ino)
+ shrinkers.append((int(items[1]), shrinker, ino))
+ return shrinkers
+
+
+def main():
+ parser = argparse.ArgumentParser(description='Display biggest shrinkers')
+ parser.add_argument('-n', '--lines', type=int, help='Number of lines to print')
+
+ args = parser.parse_args()
+
+ cgroups = scan_cgroups("/sys/fs/cgroup/")
+ shrinkers = scan_shrinkers("/sys/kernel/debug/shrinker/")
+ shrinkers = sorted(shrinkers, reverse = True, key = lambda x: x[0])
+
+ n = 0
+ for s in shrinkers:
+ count, name, ino = (s[0], s[1], s[2])
+ if count == 0:
+ break
+
+ if ino == 0 or ino == 1:
+ cg = "/"
+ else:
+ try:
+ cg = cgroups[ino]
+ except KeyError:
+ cg = "unknown (%d)" % ino
+
+ print("%-8s %-20s %s" % (count, name, cg))
+
+ n += 1
+ if args.lines and n >= args.lines:
+ break
+
+
+if __name__ == '__main__':
+ main()
--
2.35.3
