1#!/usr/bin/env drgn 2# 3# Copyright (C) 2024 Kemeng Shi <shikemeng@huaweicloud.com> 4# Copyright (C) 2024 Huawei Inc 5 6desc = """ 7This is a drgn script based on wq_monitor.py to monitor writeback info on 8backing 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 to 11 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 pages 20 back to disk. 21""" 22 23import signal 24import re 25import time 26import json 27 28import drgn 29from drgn.helpers.linux.list import list_for_each_entry 30 31import argparse 32parser = 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 out 79 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 when 95 # CONFIG_CGROUP_WRITEBACK is enabled 96 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 + '_' + ino 101 102 self.stats = [0] * NR_WB_STAT_ITEMS 103 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] = 0 108 109 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_ITEMS 115 self.avg_bw = 0 116 117 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_bw 122 123exit_req = False 124 125def sigint_handler(signr, frame): 126 global exit_req 127 exit_req = True 128 129def main(): 130 # handle args 131 Stats.table_fmt = not args.json 132 interval = args.interval 133 cgroup = args.cgroup 134 135 re_str = None 136 if args.bdi: 137 for r in args.bdi: 138 if re_str is None: 139 re_str = r 140 else: 141 re_str += '|' + r 142 143 filter_re = re.compile(re_str) if re_str else None 144 145 # monitoring loop 146 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 continue 156 157 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 break 169 time.sleep(interval) 170 171if __name__ == "__main__": 172 main() 173