iocost_monitor.py (9453B)
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 (0 exits immediately ' 32 'after checking requirements)') 33parser.add_argument('--json', action='store_true', 34 help='Output in json') 35args = parser.parse_args() 36 37def err(s): 38 print(s, file=sys.stderr, flush=True) 39 sys.exit(1) 40 41try: 42 blkcg_root = prog['blkcg_root'] 43 plid = prog['blkcg_policy_iocost'].plid.value_() 44except: 45 err('The kernel does not have iocost enabled') 46 47IOC_RUNNING = prog['IOC_RUNNING'].value_() 48WEIGHT_ONE = prog['WEIGHT_ONE'].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.address_of_(), 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_base_rate.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' : now, 116 'enabled' : self.enabled, 117 'running' : self.running, 118 'period_ms' : self.period_ms, 119 'period_at' : self.period_at, 120 'period_vtime_at' : self.vperiod_at, 121 'busy_level' : self.busy_level, 122 'vrate_pct' : 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'{"debt":>7} {"delay":>7} {"usage%"}' 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_() / WEIGHT_ONE 147 self.active = iocg.active.value_() / WEIGHT_ONE 148 self.inuse = iocg.inuse.value_() / WEIGHT_ONE 149 self.hwa_pct = iocg.hweight_active.value_() * 100 / WEIGHT_ONE 150 self.hwi_pct = iocg.hweight_inuse.value_() * 100 / WEIGHT_ONE 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.usage = (100 * iocg.usage_delta_us.value_() / 163 ioc.period_us.value_()) if self.active else 0 164 self.debt_ms = iocg.abs_vdebt.value_() / VTIME_PER_USEC / 1000 165 if blkg.use_delay.counter.value_() != 0: 166 self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000 167 else: 168 self.delay_ms = 0 169 170 def dict(self, now, path): 171 out = { 'cgroup' : path, 172 'timestamp' : now, 173 'is_active' : self.is_active, 174 'weight' : self.weight, 175 'weight_active' : self.active, 176 'weight_inuse' : self.inuse, 177 'hweight_active_pct' : self.hwa_pct, 178 'hweight_inuse_pct' : self.hwi_pct, 179 'inflight_pct' : self.inflight_pct, 180 'debt_ms' : self.debt_ms, 181 'delay_ms' : self.delay_ms, 182 'usage_pct' : self.usage, 183 'address' : self.address } 184 return out 185 186 def table_row_str(self, path): 187 out = f'{path[-28:]:28} ' \ 188 f'{"*" if self.is_active else " "} ' \ 189 f'{round(self.inuse):5}/{round(self.active):5} ' \ 190 f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \ 191 f'{self.inflight_pct:6.2f} ' \ 192 f'{self.debt_ms:7.2f} ' \ 193 f'{self.delay_ms:7.2f} '\ 194 f'{min(self.usage, 999):6.2f}' 195 out = out.rstrip(':') 196 return out 197 198# handle args 199table_fmt = not args.json 200interval = args.interval 201devname = args.devname 202 203if args.json: 204 table_fmt = False 205 206re_str = None 207if args.cgroup: 208 for r in args.cgroup: 209 if re_str is None: 210 re_str = r 211 else: 212 re_str += '|' + r 213 214filter_re = re.compile(re_str) if re_str else None 215 216# Locate the roots 217q_id = None 218root_iocg = None 219ioc = None 220 221for i, ptr in radix_tree_for_each(blkcg_root.blkg_tree.address_of_()): 222 blkg = drgn.Object(prog, 'struct blkcg_gq', address=ptr) 223 try: 224 if devname == blkg.q.kobj.parent.name.string_().decode('utf-8'): 225 q_id = blkg.q.id.value_() 226 if blkg.pd[plid]: 227 root_iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd') 228 ioc = root_iocg.ioc 229 break 230 except: 231 pass 232 233if ioc is None: 234 err(f'Could not find ioc for {devname}'); 235 236if interval == 0: 237 sys.exit(0) 238 239# Keep printing 240while True: 241 now = time.time() 242 iocstat = IocStat(ioc) 243 output = '' 244 245 if table_fmt: 246 output += '\n' + iocstat.table_preamble_str() 247 output += '\n' + iocstat.table_header_str() 248 else: 249 output += json.dumps(iocstat.dict(now)) 250 251 for path, blkg in BlkgIterator(blkcg_root, q_id): 252 if filter_re and not filter_re.match(path): 253 continue 254 if not blkg.pd[plid]: 255 continue 256 257 iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd') 258 iocg_stat = IocgStat(iocg) 259 260 if not filter_re and not iocg_stat.is_active: 261 continue 262 263 if table_fmt: 264 output += '\n' + iocg_stat.table_row_str(path) 265 else: 266 output += '\n' + json.dumps(iocg_stat.dict(now, path)) 267 268 print(output) 269 sys.stdout.flush() 270 time.sleep(interval)