linux/tools/sched_ext/scx_show_state.py
Andrea Righi 431844b65f sched_ext: Provide a sysfs enable_seq counter
As discussed during the distro-centric session within the sched_ext
Microconference at LPC 2024, introduce a sequence counter that is
incremented every time a BPF scheduler is loaded.

This feature can help distributions in diagnosing potential performance
regressions by identifying systems where users are running (or have ran)
custom BPF schedulers.

Example:

 arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq
 0
 arighi@virtme-ng~> sudo scx_simple
 local=1 global=0
 ^CEXIT: unregistered from user space
 arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq
 1

In this way user-space tools (such as Ubuntu's apport and similar) are
able to gather and include this information in bug reports.

Cc: Giovanni Gherdovich <giovanni.gherdovich@suse.com>
Cc: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Cc: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
Cc: Phil Auld <pauld@redhat.com>
Signed-off-by: Andrea Righi <andrea.righi@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-23 06:53:02 -10:00

41 lines
1.2 KiB
Python

#!/usr/bin/env drgn
#
# Copyright (C) 2024 Tejun Heo <tj@kernel.org>
# Copyright (C) 2024 Meta Platforms, Inc. and affiliates.
desc = """
This is a drgn script to show the current sched_ext state.
For more info on drgn, visit https://github.com/osandov/drgn.
"""
import drgn
import sys
def err(s):
print(s, file=sys.stderr, flush=True)
sys.exit(1)
def read_int(name):
return int(prog[name].value_())
def read_atomic(name):
return prog[name].counter.value_()
def read_static_key(name):
return prog[name].key.enabled.counter.value_()
def ops_state_str(state):
return prog['scx_ops_enable_state_str'][state].string_().decode()
ops = prog['scx_ops']
enable_state = read_atomic("scx_ops_enable_state_var")
print(f'ops : {ops.name.string_().decode()}')
print(f'enabled : {read_static_key("__scx_ops_enabled")}')
print(f'switching_all : {read_int("scx_switching_all")}')
print(f'switched_all : {read_static_key("__scx_switched_all")}')
print(f'enable_state : {ops_state_str(enable_state)} ({enable_state})')
print(f'bypass_depth : {read_atomic("scx_ops_bypass_depth")}')
print(f'nr_rejected : {read_atomic("scx_nr_rejected")}')
print(f'enable_seq : {read_atomic("scx_enable_seq")}')