#!/usr/bin/env drgn # # Copyright (C) 2019 Tejun Heo <tj@kernel.org> # Copyright (C) 2019 Facebook desc = """ This is a drgn script to monitor the blk-iocost cgroup controller. See the comment at the top of block/blk-iocost.c for more details. For drgn, visit https://github.com/osandov/drgn. """ import sys import re import time import json import math import drgn from drgn import container_of from drgn.helpers.linux.list import list_for_each_entry,list_empty from drgn.helpers.linux.radixtree import radix_tree_for_each,radix_tree_lookup import argparse parser = argparse.ArgumentParser(description=desc, formatter_class=argparse.RawTextHelpFormatter) parser.add_argument('devname', metavar='DEV', help='Target block device name (e.g. sda)') parser.add_argument('--cgroup', action='append', metavar='REGEX', help='Regex for target cgroups, ') parser.add_argument('--interval', '-i', metavar='SECONDS', type=float, default=1, help='Monitoring interval in seconds (0 exits immediately ' 'after checking requirements)') parser.add_argument('--json', action='store_true', help='Output in json') args = parser.parse_args() def err(s): print(s, file=sys.stderr, flush=True) sys.exit(1) try: blkcg_root = prog['blkcg_root'] plid = prog['blkcg_policy_iocost'].plid.value_() except: err('The kernel does not have iocost enabled') IOC_RUNNING = prog['IOC_RUNNING'].value_() WEIGHT_ONE = prog['WEIGHT_ONE'].value_() VTIME_PER_SEC = prog['VTIME_PER_SEC'].value_() VTIME_PER_USEC = prog['VTIME_PER_USEC'].value_() AUTOP_SSD_FAST = prog['AUTOP_SSD_FAST'].value_() AUTOP_SSD_DFL = prog['AUTOP_SSD_DFL'].value_() AUTOP_SSD_QD1 = prog['AUTOP_SSD_QD1'].value_() AUTOP_HDD = prog['AUTOP_HDD'].value_() autop_names = { AUTOP_SSD_FAST: 'ssd_fast', AUTOP_SSD_DFL: 'ssd_dfl', AUTOP_SSD_QD1: 'ssd_qd1', AUTOP_HDD: 'hdd', } class BlkgIterator: def __init__(self, root_blkcg, q_id, include_dying=False): self.include_dying = include_dying self.blkgs = [] self.walk(root_blkcg, q_id, '') def blkcg_name(blkcg): return blkcg.css.cgroup.kn.name.string_().decode('utf-8') def walk(self, blkcg, q_id, parent_path): if not self.include_dying and \ not (blkcg.css.flags.value_() & prog['CSS_ONLINE'].value_()): return name = BlkgIterator.blkcg_name(blkcg) path = parent_path + '/' + name if parent_path else name blkg = drgn.Object(prog, 'struct blkcg_gq', address=radix_tree_lookup(blkcg.blkg_tree.address_of_(), q_id)) if not blkg.address_: return self.blkgs.append((path if path else '/', blkg)) for c in list_for_each_entry('struct blkcg', blkcg.css.children.address_of_(), 'css.sibling'): self.walk(c, q_id, path) def __iter__(self): return iter(self.blkgs) class IocStat: def __init__(self, ioc): global autop_names self.enabled = ioc.enabled.value_() self.running = ioc.running.value_() == IOC_RUNNING self.period_ms = ioc.period_us.value_() / 1_000 self.period_at = ioc.period_at.value_() / 1_000_000 self.vperiod_at = ioc.period_at_vtime.value_() / VTIME_PER_SEC self.vrate_pct = ioc.vtime_base_rate.value_() * 100 / VTIME_PER_USEC self.busy_level = ioc.busy_level.value_() self.autop_idx = ioc.autop_idx.value_() self.user_cost_model = ioc.user_cost_model.value_() self.user_qos_params = ioc.user_qos_params.value_() if self.autop_idx in autop_names: self.autop_name = autop_names[self.autop_idx] else: self.autop_name = '?' def dict(self, now): return { 'device' : devname, 'timestamp' : now, 'enabled' : self.enabled, 'running' : self.running, 'period_ms' : self.period_ms, 'period_at' : self.period_at, 'period_vtime_at' : self.vperiod_at, 'busy_level' : self.busy_level, 'vrate_pct' : self.vrate_pct, } def table_preamble_str(self): state = ('RUN' if self.running else 'IDLE') if self.enabled else 'OFF' output = f'{devname} {state:4} ' \ f'per={self.period_ms}ms ' \ f'cur_per={self.period_at:.3f}:v{self.vperiod_at:.3f} ' \ f'busy={self.busy_level:+3} ' \ f'vrate={self.vrate_pct:6.2f}% ' \ f'params={self.autop_name}' if self.user_cost_model or self.user_qos_params: output += f'({"C" if self.user_cost_model else ""}{"Q" if self.user_qos_params else ""})' return output def table_header_str(self): return f'{"":25} active {"weight":>9} {"hweight%":>13} {"inflt%":>6} ' \ f'{"debt":>7} {"delay":>7} {"usage%"}' class IocgStat: def __init__(self, iocg): ioc = iocg.ioc blkg = iocg.pd.blkg self.is_active = not list_empty(iocg.active_list.address_of_()) self.weight = iocg.weight.value_() / WEIGHT_ONE self.active = iocg.active.value_() / WEIGHT_ONE self.inuse = iocg.inuse.value_() / WEIGHT_ONE self.hwa_pct = iocg.hweight_active.value_() * 100 / WEIGHT_ONE self.hwi_pct = iocg.hweight_inuse.value_() * 100 / WEIGHT_ONE self.address = iocg.value_() vdone = iocg.done_vtime.counter.value_() vtime = iocg.vtime.counter.value_() vrate = ioc.vtime_rate.counter.value_() period_vtime = ioc.period_us.value_() * vrate if period_vtime: self.inflight_pct = (vtime - vdone) * 100 / period_vtime else: self.inflight_pct = 0 self.usage = (100 * iocg.usage_delta_us.value_() / ioc.period_us.value_()) if self.active else 0 self.debt_ms = iocg.abs_vdebt.value_() / VTIME_PER_USEC / 1000 if blkg.use_delay.counter.value_() != 0: self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000 else: self.delay_ms = 0 def dict(self, now, path): out = { 'cgroup' : path, 'timestamp' : now, 'is_active' : self.is_active, 'weight' : self.weight, 'weight_active' : self.active, 'weight_inuse' : self.inuse, 'hweight_active_pct' : self.hwa_pct, 'hweight_inuse_pct' : self.hwi_pct, 'inflight_pct' : self.inflight_pct, 'debt_ms' : self.debt_ms, 'delay_ms' : self.delay_ms, 'usage_pct' : self.usage, 'address' : self.address } return out def table_row_str(self, path): out = f'{path[-28:]:28} ' \ f'{"*" if self.is_active else " "} ' \ f'{round(self.inuse):5}/{round(self.active):5} ' \ f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \ f'{self.inflight_pct:6.2f} ' \ f'{self.debt_ms:7.2f} ' \ f'{self.delay_ms:7.2f} '\ f'{min(self.usage, 999):6.2f}' out = out.rstrip(':') return out # handle args table_fmt = not args.json interval = args.interval devname = args.devname if args.json: table_fmt = False re_str = None if args.cgroup: for r in args.cgroup: if re_str is None: re_str = r else: re_str += '|' + r filter_re = re.compile(re_str) if re_str else None # Locate the roots q_id = None root_iocg = None ioc = None for i, ptr in radix_tree_for_each(blkcg_root.blkg_tree.address_of_()): blkg = drgn.Object(prog, 'struct blkcg_gq', address=ptr) try: if devname == blkg.q.kobj.parent.name.string_().decode('utf-8'): q_id = blkg.q.id.value_() if blkg.pd[plid]: root_iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd') ioc = root_iocg.ioc break except: pass if ioc is None: err(f'Could not find ioc for {devname}'); if interval == 0: sys.exit(0) # Keep printing while True: now = time.time() iocstat = IocStat(ioc) output = '' if table_fmt: output += '\n' + iocstat.table_preamble_str() output += '\n' + iocstat.table_header_str() else: output += json.dumps(iocstat.dict(now)) for path, blkg in BlkgIterator(blkcg_root, q_id): if filter_re and not filter_re.match(path): continue if not blkg.pd[plid]: continue iocg = container_of(blkg.pd[plid], 'struct ioc_gq', 'pd') iocg_stat = IocgStat(iocg) if not filter_re and not iocg_stat.is_active: continue if table_fmt: output += '\n' + iocg_stat.table_row_str(path) else: output += '\n' + json.dumps(iocg_stat.dict(now, path)) print(output) sys.stdout.flush() time.sleep(interval)