1#!/usr/bin/env drgn 2# 3# Copyright (C) 2019 Tejun Heo <tj@kernel.org> 4# Copyright (C) 2019 Facebook 5 6desc = """ 7This is a drgn script to monitor the blk-iocost cgroup controller. 8See the comment at the top of block/blk-iocost.c for more details. 9For drgn, visit https://github.com/osandov/drgn. 10""" 11 12import sys 13import re 14import time 15import json 16import math 17 18import drgn 19from drgn import container_of 20from drgn.helpers.linux.list import list_for_each_entry,list_empty 21from drgn.helpers.linux.radixtree import radix_tree_for_each,radix_tree_lookup 22 23import argparse 24parser = argparse.ArgumentParser(description=desc, 25 formatter_class=argparse.RawTextHelpFormatter) 26parser.add_argument('devname', metavar='DEV', 27 help='Target block device name (e.g. sda)') 28parser.add_argument('--cgroup', action='append', metavar='REGEX', 29 help='Regex for target cgroups, ') 30parser.add_argument('--interval', '-i', metavar='SECONDS', type=float, default=1, 31 help='Monitoring interval in seconds') 32parser.add_argument('--json', action='store_true', 33 help='Output in json') 34args = parser.parse_args() 35 36def err(s): 37 print(s, file=sys.stderr, flush=True) 38 sys.exit(1) 39 40try: 41 blkcg_root = prog['blkcg_root'] 42 plid = prog['blkcg_policy_iocost'].plid.value_() 43except: 44 err('The kernel does not have iocost enabled') 45 46IOC_RUNNING = prog['IOC_RUNNING'].value_() 47NR_USAGE_SLOTS = prog['NR_USAGE_SLOTS'].value_() 48HWEIGHT_WHOLE = prog['HWEIGHT_WHOLE'].value_() 49VTIME_PER_SEC = prog['VTIME_PER_SEC'].value_() 50VTIME_PER_USEC = prog['VTIME_PER_USEC'].value_() 51AUTOP_SSD_FAST = prog['AUTOP_SSD_FAST'].value_() 52AUTOP_SSD_DFL = prog['AUTOP_SSD_DFL'].value_() 53AUTOP_SSD_QD1 = prog['AUTOP_SSD_QD1'].value_() 54AUTOP_HDD = prog['AUTOP_HDD'].value_() 55 56autop_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 63class BlkgIterator: 64 def blkcg_name(blkcg): 65 return blkcg.css.cgroup.kn.name.string_().decode('utf-8') 66 67 def walk(self, blkcg, q_id, parent_path): 68 if not self.include_dying and \ 69 not (blkcg.css.flags.value_() & prog['CSS_ONLINE'].value_()): 70 return 71 72 name = BlkgIterator.blkcg_name(blkcg) 73 path = parent_path + '/' + name if parent_path else name 74 blkg = drgn.Object(prog, 'struct blkcg_gq', 75 address=radix_tree_lookup(blkcg.blkg_tree, q_id)) 76 if not blkg.address_: 77 return 78 79 self.blkgs.append((path if path else '/', blkg)) 80 81 for c in list_for_each_entry('struct blkcg', 82 blkcg.css.children.address_of_(), 'css.sibling'): 83 self.walk(c, q_id, path) 84 85 def __init__(self, root_blkcg, q_id, include_dying=False): 86 self.include_dying = include_dying 87 self.blkgs = [] 88 self.walk(root_blkcg, q_id, '') 89 90 def __iter__(self): 91 return iter(self.blkgs) 92 93class 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_rate.counter.value_() * 100 / VTIME_PER_USEC 103 self.busy_level = ioc.busy_level.value_() 104 self.autop_idx = ioc.autop_idx.value_() 105 self.user_cost_model = ioc.user_cost_model.value_() 106 self.user_qos_params = ioc.user_qos_params.value_() 107 108 if self.autop_idx in autop_names: 109 self.autop_name = autop_names[self.autop_idx] 110 else: 111 self.autop_name = '?' 112 113 def dict(self, now): 114 return { 'device' : devname, 115 'timestamp' : str(now), 116 'enabled' : str(int(self.enabled)), 117 'running' : str(int(self.running)), 118 'period_ms' : str(self.period_ms), 119 'period_at' : str(self.period_at), 120 'period_vtime_at' : str(self.vperiod_at), 121 'busy_level' : str(self.busy_level), 122 'vrate_pct' : str(self.vrate_pct), } 123 124 def table_preamble_str(self): 125 state = ('RUN' if self.running else 'IDLE') if self.enabled else 'OFF' 126 output = f'{devname} {state:4} ' \ 127 f'per={self.period_ms}ms ' \ 128 f'cur_per={self.period_at:.3f}:v{self.vperiod_at:.3f} ' \ 129 f'busy={self.busy_level:+3} ' \ 130 f'vrate={self.vrate_pct:6.2f}% ' \ 131 f'params={self.autop_name}' 132 if self.user_cost_model or self.user_qos_params: 133 output += f'({"C" if self.user_cost_model else ""}{"Q" if self.user_qos_params else ""})' 134 return output 135 136 def table_header_str(self): 137 return f'{"":25} active {"weight":>9} {"hweight%":>13} {"inflt%":>6} ' \ 138 f'{"dbt":>3} {"delay":>6} {"usages%"}' 139 140class IocgStat: 141 def __init__(self, iocg): 142 ioc = iocg.ioc 143 blkg = iocg.pd.blkg 144 145 self.is_active = not list_empty(iocg.active_list.address_of_()) 146 self.weight = iocg.weight.value_() 147 self.active = iocg.active.value_() 148 self.inuse = iocg.inuse.value_() 149 self.hwa_pct = iocg.hweight_active.value_() * 100 / HWEIGHT_WHOLE 150 self.hwi_pct = iocg.hweight_inuse.value_() * 100 / HWEIGHT_WHOLE 151 self.address = iocg.value_() 152 153 vdone = iocg.done_vtime.counter.value_() 154 vtime = iocg.vtime.counter.value_() 155 vrate = ioc.vtime_rate.counter.value_() 156 period_vtime = ioc.period_us.value_() * vrate 157 if period_vtime: 158 self.inflight_pct = (vtime - vdone) * 100 / period_vtime 159 else: 160 self.inflight_pct = 0 161 162 self.debt_ms = iocg.abs_vdebt.counter.value_() / VTIME_PER_USEC / 1000 163 self.use_delay = blkg.use_delay.counter.value_() 164 self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000 165 166 usage_idx = iocg.usage_idx.value_() 167 self.usages = [] 168 self.usage = 0 169 for i in range(NR_USAGE_SLOTS): 170 usage = iocg.usages[(usage_idx + i) % NR_USAGE_SLOTS].value_() 171 upct = usage * 100 / HWEIGHT_WHOLE 172 self.usages.append(upct) 173 self.usage = max(self.usage, upct) 174 175 def dict(self, now, path): 176 out = { 'cgroup' : path, 177 'timestamp' : str(now), 178 'is_active' : str(int(self.is_active)), 179 'weight' : str(self.weight), 180 'weight_active' : str(self.active), 181 'weight_inuse' : str(self.inuse), 182 'hweight_active_pct' : str(self.hwa_pct), 183 'hweight_inuse_pct' : str(self.hwi_pct), 184 'inflight_pct' : str(self.inflight_pct), 185 'debt_ms' : str(self.debt_ms), 186 'use_delay' : str(self.use_delay), 187 'delay_ms' : str(self.delay_ms), 188 'usage_pct' : str(self.usage), 189 'address' : str(hex(self.address)) } 190 for i in range(len(self.usages)): 191 out[f'usage_pct_{i}'] = str(self.usages[i]) 192 return out 193 194 def table_row_str(self, path): 195 out = f'{path[-28:]:28} ' \ 196 f'{"*" if self.is_active else " "} ' \ 197 f'{self.inuse:5}/{self.active:5} ' \ 198 f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \ 199 f'{self.inflight_pct:6.2f} ' \ 200 f'{min(math.ceil(self.debt_ms), 999):3} ' \ 201 f'{min(self.use_delay, 99):2}*'\ 202 f'{min(math.ceil(self.delay_ms), 999):03} ' 203 for u in self.usages: 204 out += f'{min(round(u), 999):03d}:' 205 out = out.rstrip(':') 206 return out 207 208# handle args 209table_fmt = not args.json 210interval = args.interval 211devname = args.devname 212 213if args.json: 214 table_fmt = False 215 216re_str = None 217if args.cgroup: 218 for r in args.cgroup: 219 if re_str is None: 220 re_str = r 221 else: 222 re_str += '|' + r 223 224filter_re = re.compile(re_str) if re_str else None 225 226# Locate the roots 227q_id = None 228root_iocg = None 229ioc = None 230 231for i, ptr in radix_tree_for_each(blkcg_root.blkg_tree): 232 blkg = drgn.Object(prog, 'struct blkcg_gq', address=ptr) 233 try: 234 if devname == blkg.q.kobj.parent.name.string_().decode('utf-8'): 235 q_id = blkg.q.id.value_() 236 if blkg.pd[plid]: 237 root_iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd') 238 ioc = root_iocg.ioc 239 break 240 except: 241 pass 242 243if ioc is None: 244 err(f'Could not find ioc for {devname}'); 245 246# Keep printing 247while 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) 278