1 #!/usr/bin/env drgn
2 #
3 # Copyright (C) 2019 Tejun Heo <tj@kernel.org>
4 # Copyright (C) 2019 Facebook
5
6 desc = """
7 This is a drgn script to monitor the blk-iocost cgroup controller.
8 See the comment at the top of block/blk-iocost.c for more details.
9 For drgn, visit https://github.com/osandov/drgn.
10 """
11
12 import sys
13 import re
14 import time
15 import json
16 import math
17
18 import drgn
19 from drgn import container_of
20 from drgn.helpers.linux.list import list_for_each_entry,list_empty
21 from drgn.helpers.linux.radixtree import radix_tree_for_each,radix_tree_lookup
22
23 import argparse
24 parser = argparse.ArgumentParser(description=desc,
25 formatter_class=argparse.RawTextHelpFormatter)
26 parser.add_argument('devname', metavar='DEV',
27 help='Target block device name (e.g. sda)')
28 parser.add_argument('--cgroup', action='append', metavar='REGEX',
29 help='Regex for target cgroups, ')
30 parser.add_argument('--interval', '-i', metavar='SECONDS', type=float, default=1,
31 help='Monitoring interval in seconds (0 exits immediately '
32 'after checking requirements)')
33 parser.add_argument('--json', action='store_true',
34 help='Output in json')
35 args = parser.parse_args()
36
37 def err(s):
38 print(s, file=sys.stderr, flush=True)
39 sys.exit(1)
40
41 try:
42 blkcg_root = prog['blkcg_root']
43 plid = prog['blkcg_policy_iocost'].plid.value_()
44 except:
45 err('The kernel does not have iocost enabled')
46
47 IOC_RUNNING = prog['IOC_RUNNING'].value_()
48 WEIGHT_ONE = prog['WEIGHT_ONE'].value_()
49 VTIME_PER_SEC = prog['VTIME_PER_SEC'].value_()
50 VTIME_PER_USEC = prog['VTIME_PER_USEC'].value_()
51 AUTOP_SSD_FAST = prog['AUTOP_SSD_FAST'].value_()
52 AUTOP_SSD_DFL = prog['AUTOP_SSD_DFL'].value_()
53 AUTOP_SSD_QD1 = prog['AUTOP_SSD_QD1'].value_()
54 AUTOP_HDD = prog['AUTOP_HDD'].value_()
55
56 autop_names = {
57 AUTOP_SSD_FAST: 'ssd_fast',
58 AUTOP_SSD_DFL: 'ssd_dfl',
59 AUTOP_SSD_QD1: 'ssd_qd1',
60 AUTOP_HDD: 'hdd',
61 }
62
63 class BlkgIterator:
64 def __init__(self, root_blkcg, q_id, include_dying=False):
65 self.include_dying = include_dying
66 self.blkgs = []
67 self.walk(root_blkcg, q_id, '')
68
69 def blkcg_name(blkcg):
70 return blkcg.css.cgroup.kn.name.string_().decode('utf-8')
71
72 def walk(self, blkcg, q_id, parent_path):
73 if not self.include_dying and \
74 not (blkcg.css.flags.value_() & prog['CSS_ONLINE'].value_()):
75 return
76
77 name = BlkgIterator.blkcg_name(blkcg)
78 path = parent_path + '/' + name if parent_path else name
79 blkg = drgn.Object(prog, 'struct blkcg_gq',
80 address=radix_tree_lookup(blkcg.blkg_tree.address_of_(), q_id))
81 if not blkg.address_:
82 return
83
84 self.blkgs.append((path if path else '/', blkg))
85
86 for c in list_for_each_entry('struct blkcg',
87 blkcg.css.children.address_of_(), 'css.sibling'):
88 self.walk(c, q_id, path)
89
90 def __iter__(self):
91 return iter(self.blkgs)
92
93 class IocStat:
94 def __init__(self, ioc):
95 global autop_names
96
97 self.enabled = ioc.enabled.value_()
98 self.running = ioc.running.value_() == IOC_RUNNING
99 self.period_ms = ioc.period_us.value_() / 1_000
100 self.period_at = ioc.period_at.value_() / 1_000_000
101 self.vperiod_at = ioc.period_at_vtime.value_() / VTIME_PER_SEC
102 self.vrate_pct = ioc.vtime_base_rate.value_() * 100 / VTIME_PER_USEC
103 self.ivrate_pct = ioc.vtime_rate.counter.value_() * 100 / VTIME_PER_USEC
104 self.busy_level = ioc.busy_level.value_()
105 self.autop_idx = ioc.autop_idx.value_()
106 self.user_cost_model = ioc.user_cost_model.value_()
107 self.user_qos_params = ioc.user_qos_params.value_()
108
109 if self.autop_idx in autop_names:
110 self.autop_name = autop_names[self.autop_idx]
111 else:
112 self.autop_name = '?'
113
114 def dict(self, now):
115 return { 'device' : devname,
116 'timestamp' : now,
117 'enabled' : self.enabled,
118 'running' : self.running,
119 'period_ms' : self.period_ms,
120 'period_at' : self.period_at,
121 'period_vtime_at' : self.vperiod_at,
122 'busy_level' : self.busy_level,
123 'vrate_pct' : self.vrate_pct,
124 'ivrate_pct' : self.ivrate_pct,
125 }
126
127 def table_preamble_str(self):
128 state = ('RUN' if self.running else 'IDLE') if self.enabled else 'OFF'
129 output = f'{devname} {state:4} ' \
130 f'per={self.period_ms}ms ' \
131 f'cur_per={self.period_at:.3f}:v{self.vperiod_at:.3f} ' \
132 f'busy={self.busy_level:+3} ' \
133 f'vrate={self.vrate_pct:6.2f}%:{self.ivrate_pct:6.2f}% ' \
134 f'params={self.autop_name}'
135 if self.user_cost_model or self.user_qos_params:
136 output += f'({"C" if self.user_cost_model else ""}{"Q" if self.user_qos_params else ""})'
137 return output
138
139 def table_header_str(self):
140 return f'{"":25} active {"weight":>9} {"hweight%":>13} {"inflt%":>6} ' \
141 f'{"usage%":>6} {"wait":>7} {"debt":>7} {"delay":>7}'
142
143 class IocgStat:
144 def __init__(self, iocg):
145 ioc = iocg.ioc
146 blkg = iocg.pd.blkg
147
148 self.is_active = not list_empty(iocg.active_list.address_of_())
149 self.weight = iocg.weight.value_() / WEIGHT_ONE
150 self.active = iocg.active.value_() / WEIGHT_ONE
151 self.inuse = iocg.inuse.value_() / WEIGHT_ONE
152 self.hwa_pct = iocg.hweight_active.value_() * 100 / WEIGHT_ONE
153 self.hwi_pct = iocg.hweight_inuse.value_() * 100 / WEIGHT_ONE
154 self.address = iocg.value_()
155
156 vdone = iocg.done_vtime.counter.value_()
157 vtime = iocg.vtime.counter.value_()
158 vrate = ioc.vtime_rate.counter.value_()
159 period_vtime = ioc.period_us.value_() * vrate
160 if period_vtime:
161 self.inflight_pct = (vtime - vdone) * 100 / period_vtime
162 else:
163 self.inflight_pct = 0
164
165 self.usage = (100 * iocg.usage_delta_us.value_() /
166 ioc.period_us.value_()) if self.active else 0
167 self.wait_ms = (iocg.stat.wait_us.value_() -
168 iocg.last_stat.wait_us.value_()) / 1000
169 self.debt_ms = iocg.abs_vdebt.value_() / VTIME_PER_USEC / 1000
170 if blkg.use_delay.counter.value_() != 0:
171 self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000
172 else:
173 self.delay_ms = 0
174
175 def dict(self, now, path):
176 out = { 'cgroup' : path,
177 'timestamp' : now,
178 'is_active' : self.is_active,
179 'weight' : self.weight,
180 'weight_active' : self.active,
181 'weight_inuse' : self.inuse,
182 'hweight_active_pct' : self.hwa_pct,
183 'hweight_inuse_pct' : self.hwi_pct,
184 'inflight_pct' : self.inflight_pct,
185 'usage_pct' : self.usage,
186 'wait_ms' : self.wait_ms,
187 'debt_ms' : self.debt_ms,
188 'delay_ms' : self.delay_ms,
189 'address' : self.address }
190 return out
191
192 def table_row_str(self, path):
193 out = f'{path[-28:]:28} ' \
194 f'{"*" if self.is_active else " "} ' \
195 f'{round(self.inuse):5}/{round(self.active):5} ' \
196 f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \
197 f'{self.inflight_pct:6.2f} ' \
198 f'{min(self.usage, 999):6.2f} ' \
199 f'{self.wait_ms:7.2f} ' \
200 f'{self.debt_ms:7.2f} ' \
201 f'{self.delay_ms:7.2f}'
202 out = out.rstrip(':')
203 return out
204
205 # handle args
206 table_fmt = not args.json
207 interval = args.interval
208 devname = args.devname
209
210 if args.json:
211 table_fmt = False
212
213 re_str = None
214 if args.cgroup:
215 for r in args.cgroup:
216 if re_str is None:
217 re_str = r
218 else:
219 re_str += '|' + r
220
221 filter_re = re.compile(re_str) if re_str else None
222
223 # Locate the roots
224 q_id = None
225 root_iocg = None
226 ioc = None
227
228 for i, ptr in radix_tree_for_each(blkcg_root.blkg_tree.address_of_()):
229 blkg = drgn.Object(prog, 'struct blkcg_gq', address=ptr)
230 try:
231 if devname == blkg.q.mq_kobj.parent.name.string_().decode('utf-8'):
232 q_id = blkg.q.id.value_()
233 if blkg.pd[plid]:
234 root_iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd')
235 ioc = root_iocg.ioc
236 break
237 except:
238 pass
239
240 if ioc is None:
241 err(f'Could not find ioc for {devname}');
242
243 if interval == 0:
244 sys.exit(0)
245
246 # Keep printing
247 while True:
248 now = time.time()
249 iocstat = IocStat(ioc)
250 output = ''
251
252 if table_fmt:
253 output += '\n' + iocstat.table_preamble_str()
254 output += '\n' + iocstat.table_header_str()
255 else:
256 output += json.dumps(iocstat.dict(now))
257
258 for path, blkg in BlkgIterator(blkcg_root, q_id):
259 if filter_re and not filter_re.match(path):
260 continue
261 if not blkg.pd[plid]:
262 continue
263
264 iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd')
265 iocg_stat = IocgStat(iocg)
266
267 if not filter_re and not iocg_stat.is_active:
268 continue
269
270 if table_fmt:
271 output += '\n' + iocg_stat.table_row_str(path)
272 else:
273 output += '\n' + json.dumps(iocg_stat.dict(now, path))
274
275 print(output)
276 sys.stdout.flush()
277 time.sleep(interval)
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