1#!/usr/bin/env drgn 2# SPDX-License-Identifier: GPL-2.0 3# Copyright (C) 2025 Juri Lelli <juri.lelli@redhat.com> 4# Copyright (C) 2025 Red Hat, Inc. 5 6desc = """ 7This is a drgn script to show the current root domains configuration. For more 8info on drgn, visit https://github.com/osandov/drgn. 9 10Root domains are only printed once, as multiple CPUs might be attached to the 11same root domain. 12""" 13 14import os 15import argparse 16 17import drgn 18from drgn import FaultError 19from drgn.helpers.common import * 20from drgn.helpers.linux import * 21 22def print_root_domains_info(): 23 24 # To store unique root domains found 25 seen_root_domains = set() 26 27 print("Retrieving (unique) Root Domain Information:") 28 29 runqueues = prog['runqueues'] 30 def_root_domain = prog['def_root_domain'] 31 32 for cpu_id in for_each_possible_cpu(prog): 33 try: 34 rq = per_cpu(runqueues, cpu_id) 35 36 root_domain = rq.rd 37 38 # Check if we've already processed this root domain to avoid duplicates 39 # Use the memory address of the root_domain as a unique identifier 40 root_domain_cast = int(root_domain) 41 if root_domain_cast in seen_root_domains: 42 continue 43 seen_root_domains.add(root_domain_cast) 44 45 if root_domain_cast == int(def_root_domain.address_): 46 print(f"\n--- Root Domain @ def_root_domain ---") 47 else: 48 print(f"\n--- Root Domain @ 0x{root_domain_cast:x} ---") 49 50 print(f" From CPU: {cpu_id}") # This CPU belongs to this root domain 51 52 # Access and print relevant fields from struct root_domain 53 print(f" Span : {cpumask_to_cpulist(root_domain.span[0])}") 54 print(f" Online : {cpumask_to_cpulist(root_domain.span[0])}") 55 56 except drgn.FaultError as fe: 57 print(f" (CPU {cpu_id}: Fault accessing kernel memory: {fe})") 58 except AttributeError as ae: 59 print(f" (CPU {cpu_id}: Missing attribute for root_domain (kernel struct change?): {ae})") 60 except Exception as e: 61 print(f" (CPU {cpu_id}: An unexpected error occurred: {e})") 62 63if __name__ == "__main__": 64 parser = argparse.ArgumentParser(description=desc, 65 formatter_class=argparse.RawTextHelpFormatter) 66 args = parser.parse_args() 67 68 print_root_domains_info() 69