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0005
0006 from os import stat
0007 import argparse
0008 import sys
0009
0010 from drgn.helpers.linux import list_for_each_entry, list_empty
0011 from drgn.helpers.linux import for_each_page
0012 from drgn.helpers.linux.cpumask import for_each_online_cpu
0013 from drgn.helpers.linux.percpu import per_cpu_ptr
0014 from drgn import container_of, FaultError, Object, cast
0015
0016
0017 DESC = """
0018 This is a drgn script to provide slab statistics for memory cgroups.
0019 It supports cgroup v2 and v1 and can emulate memory.kmem.slabinfo
0020 interface of cgroup v1.
0021 For drgn, visit https://github.com/osandov/drgn.
0022 """
0023
0024
0025 MEMCGS = {}
0026
0027 OO_SHIFT = 16
0028 OO_MASK = ((1 << OO_SHIFT) - 1)
0029
0030
0031 def err(s):
0032 print('slabinfo.py: error: %s' % s, file=sys.stderr, flush=True)
0033 sys.exit(1)
0034
0035
0036 def find_memcg_ids(css=prog['root_mem_cgroup'].css, prefix=''):
0037 if not list_empty(css.children.address_of_()):
0038 for css in list_for_each_entry('struct cgroup_subsys_state',
0039 css.children.address_of_(),
0040 'sibling'):
0041 name = prefix + '/' + css.cgroup.kn.name.string_().decode('utf-8')
0042 memcg = container_of(css, 'struct mem_cgroup', 'css')
0043 MEMCGS[css.cgroup.kn.id.value_()] = memcg
0044 find_memcg_ids(css, name)
0045
0046
0047 def is_root_cache(s):
0048 try:
0049 return False if s.memcg_params.root_cache else True
0050 except AttributeError:
0051 return True
0052
0053
0054 def cache_name(s):
0055 if is_root_cache(s):
0056 return s.name.string_().decode('utf-8')
0057 else:
0058 return s.memcg_params.root_cache.name.string_().decode('utf-8')
0059
0060
0061
0062
0063 def oo_order(s):
0064 return s.oo.x >> OO_SHIFT
0065
0066
0067 def oo_objects(s):
0068 return s.oo.x & OO_MASK
0069
0070
0071 def count_partial(n, fn):
0072 nr_objs = 0
0073 for slab in list_for_each_entry('struct slab', n.partial.address_of_(),
0074 'slab_list'):
0075 nr_objs += fn(slab)
0076 return nr_objs
0077
0078
0079 def count_free(slab):
0080 return slab.objects - slab.inuse
0081
0082
0083 def slub_get_slabinfo(s, cfg):
0084 nr_slabs = 0
0085 nr_objs = 0
0086 nr_free = 0
0087
0088 for node in range(cfg['nr_nodes']):
0089 n = s.node[node]
0090 nr_slabs += n.nr_slabs.counter.value_()
0091 nr_objs += n.total_objects.counter.value_()
0092 nr_free += count_partial(n, count_free)
0093
0094 return {'active_objs': nr_objs - nr_free,
0095 'num_objs': nr_objs,
0096 'active_slabs': nr_slabs,
0097 'num_slabs': nr_slabs,
0098 'objects_per_slab': oo_objects(s),
0099 'cache_order': oo_order(s),
0100 'limit': 0,
0101 'batchcount': 0,
0102 'shared': 0,
0103 'shared_avail': 0}
0104
0105
0106 def cache_show(s, cfg, objs):
0107 if cfg['allocator'] == 'SLUB':
0108 sinfo = slub_get_slabinfo(s, cfg)
0109 else:
0110 err('SLAB isn\'t supported yet')
0111
0112 if cfg['shared_slab_pages']:
0113 sinfo['active_objs'] = objs
0114 sinfo['num_objs'] = objs
0115
0116 print('%-17s %6lu %6lu %6u %4u %4d'
0117 ' : tunables %4u %4u %4u'
0118 ' : slabdata %6lu %6lu %6lu' % (
0119 cache_name(s), sinfo['active_objs'], sinfo['num_objs'],
0120 s.size, sinfo['objects_per_slab'], 1 << sinfo['cache_order'],
0121 sinfo['limit'], sinfo['batchcount'], sinfo['shared'],
0122 sinfo['active_slabs'], sinfo['num_slabs'],
0123 sinfo['shared_avail']))
0124
0125
0126 def detect_kernel_config():
0127 cfg = {}
0128
0129 cfg['nr_nodes'] = prog['nr_online_nodes'].value_()
0130
0131 if prog.type('struct kmem_cache').members[1].name == 'flags':
0132 cfg['allocator'] = 'SLUB'
0133 elif prog.type('struct kmem_cache').members[1].name == 'batchcount':
0134 cfg['allocator'] = 'SLAB'
0135 else:
0136 err('Can\'t determine the slab allocator')
0137
0138 cfg['shared_slab_pages'] = False
0139 try:
0140 if prog.type('struct obj_cgroup'):
0141 cfg['shared_slab_pages'] = True
0142 except:
0143 pass
0144
0145 return cfg
0146
0147
0148 def for_each_slab(prog):
0149 PGSlab = 1 << prog.constant('PG_slab')
0150 PGHead = 1 << prog.constant('PG_head')
0151
0152 for page in for_each_page(prog):
0153 try:
0154 if page.flags.value_() & PGSlab:
0155 yield cast('struct slab *', page)
0156 except FaultError:
0157 pass
0158
0159
0160 def main():
0161 parser = argparse.ArgumentParser(description=DESC,
0162 formatter_class=
0163 argparse.RawTextHelpFormatter)
0164 parser.add_argument('cgroup', metavar='CGROUP',
0165 help='Target memory cgroup')
0166 args = parser.parse_args()
0167
0168 try:
0169 cgroup_id = stat(args.cgroup).st_ino
0170 find_memcg_ids()
0171 memcg = MEMCGS[cgroup_id]
0172 except KeyError:
0173 err('Can\'t find the memory cgroup')
0174
0175 cfg = detect_kernel_config()
0176
0177 print('# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>'
0178 ' : tunables <limit> <batchcount> <sharedfactor>'
0179 ' : slabdata <active_slabs> <num_slabs> <sharedavail>')
0180
0181 if cfg['shared_slab_pages']:
0182 obj_cgroups = set()
0183 stats = {}
0184 caches = {}
0185
0186
0187 obj_cgroups.add(memcg.objcg.value_())
0188 for ptr in list_for_each_entry('struct obj_cgroup',
0189 memcg.objcg_list.address_of_(),
0190 'list'):
0191 obj_cgroups.add(ptr.value_())
0192
0193
0194
0195 for slab in for_each_slab(prog):
0196 objcg_vec_raw = slab.memcg_data.value_()
0197 if objcg_vec_raw == 0:
0198 continue
0199 cache = slab.slab_cache
0200 if not cache:
0201 continue
0202 addr = cache.value_()
0203 caches[addr] = cache
0204
0205 objcg_vec = Object(prog, 'struct obj_cgroup **',
0206 value=objcg_vec_raw & ~1)
0207
0208 if addr not in stats:
0209 stats[addr] = 0
0210
0211 for i in range(oo_objects(cache)):
0212 if objcg_vec[i].value_() in obj_cgroups:
0213 stats[addr] += 1
0214
0215 for addr in caches:
0216 if stats[addr] > 0:
0217 cache_show(caches[addr], cfg, stats[addr])
0218
0219 else:
0220 for s in list_for_each_entry('struct kmem_cache',
0221 memcg.kmem_caches.address_of_(),
0222 'memcg_params.kmem_caches_node'):
0223 cache_show(s, cfg, None)
0224
0225
0226 main()
