| #!/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_() |
| NR_USAGE_SLOTS = prog['NR_USAGE_SLOTS'].value_() |
| HWEIGHT_WHOLE = prog['HWEIGHT_WHOLE'].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 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 __init__(self, root_blkcg, q_id, include_dying=False): |
| self.include_dying = include_dying |
| self.blkgs = [] |
| self.walk(root_blkcg, q_id, '') |
| |
| 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_rate.counter.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'{"dbt":>3} {"delay":>6} {"usages%"}' |
| |
| 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_() |
| self.active = iocg.active.value_() |
| self.inuse = iocg.inuse.value_() |
| self.hwa_pct = iocg.hweight_active.value_() * 100 / HWEIGHT_WHOLE |
| self.hwi_pct = iocg.hweight_inuse.value_() * 100 / HWEIGHT_WHOLE |
| 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 |
| |
| # vdebt used to be an atomic64_t and is now u64, support both |
| try: |
| self.debt_ms = iocg.abs_vdebt.counter.value_() / VTIME_PER_USEC / 1000 |
| except: |
| self.debt_ms = iocg.abs_vdebt.value_() / VTIME_PER_USEC / 1000 |
| |
| self.use_delay = blkg.use_delay.counter.value_() |
| self.delay_ms = blkg.delay_nsec.counter.value_() / 1_000_000 |
| |
| usage_idx = iocg.usage_idx.value_() |
| self.usages = [] |
| self.usage = 0 |
| for i in range(NR_USAGE_SLOTS): |
| usage = iocg.usages[(usage_idx + i) % NR_USAGE_SLOTS].value_() |
| upct = usage * 100 / HWEIGHT_WHOLE |
| self.usages.append(upct) |
| self.usage = max(self.usage, upct) |
| |
| 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, |
| 'use_delay' : self.use_delay, |
| 'delay_ms' : self.delay_ms, |
| 'usage_pct' : self.usage, |
| 'address' : self.address } |
| for i in range(len(self.usages)): |
| out[f'usage_pct_{i}'] = str(self.usages[i]) |
| return out |
| |
| def table_row_str(self, path): |
| out = f'{path[-28:]:28} ' \ |
| f'{"*" if self.is_active else " "} ' \ |
| f'{self.inuse:5}/{self.active:5} ' \ |
| f'{self.hwi_pct:6.2f}/{self.hwa_pct:6.2f} ' \ |
| f'{self.inflight_pct:6.2f} ' \ |
| f'{min(math.ceil(self.debt_ms), 999):3} ' \ |
| f'{min(self.use_delay, 99):2}*'\ |
| f'{min(math.ceil(self.delay_ms), 999):03} ' |
| for u in self.usages: |
| out += f'{min(round(u), 999):03d}:' |
| 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) |
