selftests/hid: fix ruff linter complains
[linux-block.git] / tools / cgroup / memcg_slabinfo.py
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1#!/usr/bin/env drgn
2#
3# Copyright (C) 2020 Roman Gushchin <guro@fb.com>
4# Copyright (C) 2020 Facebook
5
6from os import stat
7import argparse
8import sys
9
10from drgn.helpers.linux import list_for_each_entry, list_empty
11from drgn.helpers.linux import for_each_page
12from drgn.helpers.linux.cpumask import for_each_online_cpu
13from drgn.helpers.linux.percpu import per_cpu_ptr
22194473 14from drgn import container_of, FaultError, Object, cast
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15
16
17DESC = """
18This is a drgn script to provide slab statistics for memory cgroups.
19It supports cgroup v2 and v1 and can emulate memory.kmem.slabinfo
20interface of cgroup v1.
21For drgn, visit https://github.com/osandov/drgn.
22"""
23
24
25MEMCGS = {}
26
27OO_SHIFT = 16
28OO_MASK = ((1 << OO_SHIFT) - 1)
29
30
31def err(s):
32 print('slabinfo.py: error: %s' % s, file=sys.stderr, flush=True)
33 sys.exit(1)
34
35
36def find_memcg_ids(css=prog['root_mem_cgroup'].css, prefix=''):
37 if not list_empty(css.children.address_of_()):
38 for css in list_for_each_entry('struct cgroup_subsys_state',
39 css.children.address_of_(),
40 'sibling'):
41 name = prefix + '/' + css.cgroup.kn.name.string_().decode('utf-8')
42 memcg = container_of(css, 'struct mem_cgroup', 'css')
43 MEMCGS[css.cgroup.kn.id.value_()] = memcg
44 find_memcg_ids(css, name)
45
46
47def is_root_cache(s):
48 try:
49 return False if s.memcg_params.root_cache else True
50 except AttributeError:
51 return True
52
53
54def cache_name(s):
55 if is_root_cache(s):
56 return s.name.string_().decode('utf-8')
57 else:
58 return s.memcg_params.root_cache.name.string_().decode('utf-8')
59
60
61# SLUB
62
63def oo_order(s):
64 return s.oo.x >> OO_SHIFT
65
66
67def oo_objects(s):
68 return s.oo.x & OO_MASK
69
70
71def count_partial(n, fn):
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72 nr_objs = 0
73 for slab in list_for_each_entry('struct slab', n.partial.address_of_(),
74 'slab_list'):
75 nr_objs += fn(slab)
76 return nr_objs
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77
78
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79def count_free(slab):
80 return slab.objects - slab.inuse
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81
82
83def slub_get_slabinfo(s, cfg):
84 nr_slabs = 0
85 nr_objs = 0
86 nr_free = 0
87
88 for node in range(cfg['nr_nodes']):
89 n = s.node[node]
90 nr_slabs += n.nr_slabs.counter.value_()
91 nr_objs += n.total_objects.counter.value_()
92 nr_free += count_partial(n, count_free)
93
94 return {'active_objs': nr_objs - nr_free,
95 'num_objs': nr_objs,
96 'active_slabs': nr_slabs,
97 'num_slabs': nr_slabs,
98 'objects_per_slab': oo_objects(s),
99 'cache_order': oo_order(s),
100 'limit': 0,
101 'batchcount': 0,
102 'shared': 0,
103 'shared_avail': 0}
104
105
106def cache_show(s, cfg, objs):
107 if cfg['allocator'] == 'SLUB':
108 sinfo = slub_get_slabinfo(s, cfg)
109 else:
110 err('SLAB isn\'t supported yet')
111
112 if cfg['shared_slab_pages']:
113 sinfo['active_objs'] = objs
114 sinfo['num_objs'] = objs
115
116 print('%-17s %6lu %6lu %6u %4u %4d'
117 ' : tunables %4u %4u %4u'
118 ' : slabdata %6lu %6lu %6lu' % (
119 cache_name(s), sinfo['active_objs'], sinfo['num_objs'],
120 s.size, sinfo['objects_per_slab'], 1 << sinfo['cache_order'],
121 sinfo['limit'], sinfo['batchcount'], sinfo['shared'],
122 sinfo['active_slabs'], sinfo['num_slabs'],
123 sinfo['shared_avail']))
124
125
126def detect_kernel_config():
127 cfg = {}
128
129 cfg['nr_nodes'] = prog['nr_online_nodes'].value_()
130
1974c45d 131 if prog.type('struct kmem_cache').members[1].name == 'flags':
fbc1ac9d 132 cfg['allocator'] = 'SLUB'
1974c45d 133 elif prog.type('struct kmem_cache').members[1].name == 'batchcount':
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134 cfg['allocator'] = 'SLAB'
135 else:
136 err('Can\'t determine the slab allocator')
137
138 cfg['shared_slab_pages'] = False
139 try:
140 if prog.type('struct obj_cgroup'):
141 cfg['shared_slab_pages'] = True
142 except:
143 pass
144
145 return cfg
146
147
22194473 148def for_each_slab(prog):
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149 PGSlab = 1 << prog.constant('PG_slab')
150 PGHead = 1 << prog.constant('PG_head')
151
152 for page in for_each_page(prog):
153 try:
154 if page.flags.value_() & PGSlab:
22194473 155 yield cast('struct slab *', page)
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156 except FaultError:
157 pass
158
159
160def main():
161 parser = argparse.ArgumentParser(description=DESC,
162 formatter_class=
163 argparse.RawTextHelpFormatter)
164 parser.add_argument('cgroup', metavar='CGROUP',
165 help='Target memory cgroup')
166 args = parser.parse_args()
167
168 try:
169 cgroup_id = stat(args.cgroup).st_ino
170 find_memcg_ids()
171 memcg = MEMCGS[cgroup_id]
172 except KeyError:
173 err('Can\'t find the memory cgroup')
174
175 cfg = detect_kernel_config()
176
177 print('# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>'
178 ' : tunables <limit> <batchcount> <sharedfactor>'
179 ' : slabdata <active_slabs> <num_slabs> <sharedavail>')
180
181 if cfg['shared_slab_pages']:
182 obj_cgroups = set()
183 stats = {}
184 caches = {}
185
186 # find memcg pointers belonging to the specified cgroup
187 obj_cgroups.add(memcg.objcg.value_())
188 for ptr in list_for_each_entry('struct obj_cgroup',
189 memcg.objcg_list.address_of_(),
190 'list'):
191 obj_cgroups.add(ptr.value_())
192
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193 # look over all slab folios and look for objects belonging
194 # to the given memory cgroup
195 for slab in for_each_slab(prog):
196 objcg_vec_raw = slab.memcg_data.value_()
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197 if objcg_vec_raw == 0:
198 continue
22194473 199 cache = slab.slab_cache
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200 if not cache:
201 continue
202 addr = cache.value_()
203 caches[addr] = cache
204 # clear the lowest bit to get the true obj_cgroups
1974c45d 205 objcg_vec = Object(prog, 'struct obj_cgroup **',
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206 value=objcg_vec_raw & ~1)
207
208 if addr not in stats:
209 stats[addr] = 0
210
211 for i in range(oo_objects(cache)):
212 if objcg_vec[i].value_() in obj_cgroups:
213 stats[addr] += 1
214
215 for addr in caches:
216 if stats[addr] > 0:
217 cache_show(caches[addr], cfg, stats[addr])
218
219 else:
220 for s in list_for_each_entry('struct kmem_cache',
221 memcg.kmem_caches.address_of_(),
222 'memcg_params.kmem_caches_node'):
223 cache_show(s, cfg, None)
224
225
226main()