cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

rcu-cbs.py (1108B)

      1#!/usr/bin/env drgn
      2# SPDX-License-Identifier: GPL-2.0+
      3#
      4# Dump out the number of RCU callbacks outstanding.
      5#
      6# On older kernels having multiple flavors of RCU, this dumps out the
      7# number of callbacks for the most heavily used flavor.
      8#
      9# Usage: sudo drgn rcu-cbs.py
     10#
     11# Copyright (C) 2021 Facebook, Inc.
     12#
     13# Authors: Paul E. McKenney <paulmck@kernel.org>
     14
     15import sys
     16import drgn
     17from drgn import NULL, Object
     18from drgn.helpers.linux import *
     19
     20def get_rdp0(prog):
     21	try:
     22		rdp0 = prog.variable('rcu_preempt_data', 'kernel/rcu/tree.c');
     23	except LookupError:
     24		rdp0 = NULL;
     25
     26	if rdp0 == NULL:
     27		try:
     28			rdp0 = prog.variable('rcu_sched_data',
     29					     'kernel/rcu/tree.c');
     30		except LookupError:
     31			rdp0 = NULL;
     32
     33	if rdp0 == NULL:
     34		rdp0 = prog.variable('rcu_data', 'kernel/rcu/tree.c');
     35	return rdp0.address_of_();
     36
     37rdp0 = get_rdp0(prog);
     38
     39# Sum up RCU callbacks.
     40sum = 0;
     41for cpu in for_each_possible_cpu(prog):
     42	rdp = per_cpu_ptr(rdp0, cpu);
     43	len = rdp.cblist.len.value_();
     44	# print("CPU " + str(cpu) + " RCU callbacks: " + str(len));
     45	sum += len;
     46print("Number of RCU callbacks in flight: " + str(sum));