173 lines · python
1#!/usr/bin/env drgn2#3# Copyright (C) 2024 Kemeng Shi <shikemeng@huaweicloud.com>4# Copyright (C) 2024 Huawei Inc5 6desc = """7This is a drgn script based on wq_monitor.py to monitor writeback info on8backing dev. For more info on drgn, visit https://github.com/osandov/drgn.9 10 writeback(kB) Amount of dirty pages are currently being written back to11 disk.12 13 reclaimable(kB) Amount of pages are currently reclaimable.14 15 dirtied(kB) Amount of pages have been dirtied.16 17 wrttien(kB) Amount of dirty pages have been written back to disk.18 19 avg_wb(kBps) Smoothly estimated write bandwidth of writing dirty pages20 back to disk.21"""22 23import signal24import re25import time26import json27 28import drgn29from drgn.helpers.linux.list import list_for_each_entry30 31import argparse32parser = argparse.ArgumentParser(description=desc,33 formatter_class=argparse.RawTextHelpFormatter)34parser.add_argument('bdi', metavar='REGEX', nargs='*',35 help='Target backing device name patterns (all if empty)')36parser.add_argument('-i', '--interval', metavar='SECS', type=float, default=1,37 help='Monitoring interval (0 to print once and exit)')38parser.add_argument('-j', '--json', action='store_true',39 help='Output in json')40parser.add_argument('-c', '--cgroup', action='store_true',41 help='show writeback of bdi in cgroup')42args = parser.parse_args()43 44bdi_list = prog['bdi_list']45 46WB_RECLAIMABLE = prog['WB_RECLAIMABLE']47WB_WRITEBACK = prog['WB_WRITEBACK']48WB_DIRTIED = prog['WB_DIRTIED']49WB_WRITTEN = prog['WB_WRITTEN']50NR_WB_STAT_ITEMS = prog['NR_WB_STAT_ITEMS']51 52PAGE_SHIFT = prog['PAGE_SHIFT']53 54def K(x):55 return x << (PAGE_SHIFT - 10)56 57class Stats:58 def dict(self, now):59 return { 'timestamp' : now,60 'name' : self.name,61 'writeback' : self.stats[WB_WRITEBACK],62 'reclaimable' : self.stats[WB_RECLAIMABLE],63 'dirtied' : self.stats[WB_DIRTIED],64 'written' : self.stats[WB_WRITTEN],65 'avg_wb' : self.avg_bw, }66 67 def table_header_str():68 return f'{"":>16} {"writeback":>10} {"reclaimable":>12} ' \69 f'{"dirtied":>9} {"written":>9} {"avg_bw":>9}'70 71 def table_row_str(self):72 out = f'{self.name[-16:]:16} ' \73 f'{self.stats[WB_WRITEBACK]:10} ' \74 f'{self.stats[WB_RECLAIMABLE]:12} ' \75 f'{self.stats[WB_DIRTIED]:9} ' \76 f'{self.stats[WB_WRITTEN]:9} ' \77 f'{self.avg_bw:9} '78 return out79 80 def show_header():81 if Stats.table_fmt:82 print()83 print(Stats.table_header_str())84 85 def show_stats(self):86 if Stats.table_fmt:87 print(self.table_row_str())88 else:89 print(self.dict(Stats.now))90 91class WbStats(Stats):92 def __init__(self, wb):93 bdi_name = wb.bdi.dev_name.string_().decode()94 # avoid to use bdi.wb.memcg_css which is only defined when95 # CONFIG_CGROUP_WRITEBACK is enabled96 if wb == wb.bdi.wb.address_of_():97 ino = "1"98 else:99 ino = str(wb.memcg_css.cgroup.kn.id.value_())100 self.name = bdi_name + '_' + ino101 102 self.stats = [0] * NR_WB_STAT_ITEMS103 for i in range(NR_WB_STAT_ITEMS):104 if wb.stat[i].count >= 0:105 self.stats[i] = int(K(wb.stat[i].count))106 else:107 self.stats[i] = 0108 109 self.avg_bw = int(K(wb.avg_write_bandwidth))110 111class BdiStats(Stats):112 def __init__(self, bdi):113 self.name = bdi.dev_name.string_().decode()114 self.stats = [0] * NR_WB_STAT_ITEMS115 self.avg_bw = 0116 117 def collectStats(self, wb_stats):118 for i in range(NR_WB_STAT_ITEMS):119 self.stats[i] += wb_stats.stats[i]120 121 self.avg_bw += wb_stats.avg_bw122 123exit_req = False124 125def sigint_handler(signr, frame):126 global exit_req127 exit_req = True128 129def main():130 # handle args131 Stats.table_fmt = not args.json132 interval = args.interval133 cgroup = args.cgroup134 135 re_str = None136 if args.bdi:137 for r in args.bdi:138 if re_str is None:139 re_str = r140 else:141 re_str += '|' + r142 143 filter_re = re.compile(re_str) if re_str else None144 145 # monitoring loop146 signal.signal(signal.SIGINT, sigint_handler)147 148 while not exit_req:149 Stats.now = time.time()150 151 Stats.show_header()152 for bdi in list_for_each_entry('struct backing_dev_info', bdi_list.address_of_(), 'bdi_list'):153 bdi_stats = BdiStats(bdi)154 if filter_re and not filter_re.search(bdi_stats.name):155 continue156 157 for wb in list_for_each_entry('struct bdi_writeback', bdi.wb_list.address_of_(), 'bdi_node'):158 wb_stats = WbStats(wb)159 bdi_stats.collectStats(wb_stats)160 if cgroup:161 wb_stats.show_stats()162 163 bdi_stats.show_stats()164 if cgroup and Stats.table_fmt:165 print()166 167 if interval == 0:168 break169 time.sleep(interval)170 171if __name__ == "__main__":172 main()173