[v4,0/2] Add cpupower idle-state functionality

This patch series adds idle-state functionality to control cpu power
usage and to test idle states.

The number of cpus was needed in the cpupower file; I extracted out the
previously local to tuna-cli.py functionality to a separate file so the
cpu code can be used in any file in Tuna and reduce duplications. The
nics code was similar so it was also extracted to reduce the number of
global variables.

Sincerely,
John Wyatt
Software Engineer, Core Kernel
Red Hat

Changes v3 -> v4:
- Additional changes suggest by John Kacur around the use of
  @classmethods that they should've been @staticmethods and the changes
  needed for them.
- Changed the SPDX lines to be at the top of the files as requested by
  John Kacur.

Changes v2 -> v3:
- Several small improvements suggested by John Kacur off list including
  removing unnecessary string interpolation, renaming idle-set to idle_set,
  and correct placement of docstrings.

Changes v1 -> v2:
- Numerous improvements suggested by Crystal Wood including message
  text, output, error handling, moving a function to utils.py and
  structure of the code.
- Fixed a libcpupower bindings detection error that did not show on
  my local machine but did on a fresh install of Fedora GNOME 40
  reported by John Kacur.

John B. Wyatt IV (2):
  tuna: extract common cpu and nics determination code into a utils.py
    file
  tuna: Add idle_state control functionality

 tuna-cmd.py      |  64 +++++++++--------
 tuna/cpupower.py | 184 +++++++++++++++++++++++++++++++++++++++++++++++
 tuna/utils.py    |  28 ++++++++
 3 files changed, 246 insertions(+), 30 deletions(-)
 create mode 100755 tuna/cpupower.py
 create mode 100644 tuna/utils.py

On Tue, Mar 11, 2025 at 04:30:18PM -0400, John B. Wyatt IV wrote:
> Extracting the code allows these previously local (global to the file)
> variables and functions to be used in other files of tuna. Reducing
> the number of globals makes the code cleaner and reduces the size of
> tuna-cmd.py.
> 
> Included a suggestion by Crystal to move a function from the latter
> patch into utils.py and make it dependant on get_nr_cpus() (v2).
> 
> Included a request by John Kacur to place the SPDX message at the top of
> the file (v4).
> 
> Suggested-by: Crystal Wood <crwood@redhat.com>
> 
> Signed-off-by: John B. Wyatt IV <jwyatt@redhat.com>
> Signed-off-by: John B. Wyatt IV <sageofredondo@gmail.com>
> ---
>  tuna-cmd.py   | 34 +++++++---------------------------
>  tuna/utils.py | 28 ++++++++++++++++++++++++++++
>  2 files changed, 35 insertions(+), 27 deletions(-)
>  create mode 100644 tuna/utils.py
> 
> diff --git a/tuna-cmd.py b/tuna-cmd.py
> index f37e286..d0323f5 100755
> --- a/tuna-cmd.py
> +++ b/tuna-cmd.py
> @@ -21,7 +21,7 @@ from functools import reduce
>  import tuna.new_eth as ethtool
>  import tuna.tuna_sched as tuna_sched
>  import procfs
> -from tuna import tuna, sysfs
> +from tuna import tuna, sysfs, utils
>  import logging
>  import time
>  import shutil
> @@ -76,7 +76,6 @@ except:
>  
>  # FIXME: ETOOMANYGLOBALS, we need a class!
>  
> -nr_cpus = None
>  ps = None
>  irqs = None
>  
> @@ -233,25 +232,6 @@ def gen_parser():
>      return parser
>  
>  
> -def get_nr_cpus():
> -    """ Get all cpus including disabled cpus """
> -    global nr_cpus
> -    if nr_cpus:
> -        return nr_cpus
> -    nr_cpus = os.sysconf('SC_NPROCESSORS_CONF')
> -    return nr_cpus
> -
> -nics = None
> -
> -
> -def get_nics():
> -    global nics
> -    if nics:
> -        return nics
> -    nics = ethtool.get_active_devices()
> -    return nics
> -
> -
>  def thread_help(tid):
>      global ps
>      if not ps:
> @@ -277,7 +257,7 @@ def save(cpu_list, thread_list, filename):
>          if (cpu_list and not set(kt.affinity).intersection(set(cpu_list))) or \
>             (thread_list and kt.pid not in thread_list):
>              del kthreads[name]
> -    tuna.generate_rtgroups(filename, kthreads, get_nr_cpus())
> +    tuna.generate_rtgroups(filename, kthreads, utils.get_nr_cpus())
>  
>  
>  def ps_show_header(has_ctxt_switch_info, cgroups=False):
> @@ -328,7 +308,7 @@ def format_affinity(affinity):
>      if len(affinity) <= 4:
>          return ",".join(str(a) for a in affinity)
>  
> -    return ",".join(str(hex(a)) for a in procfs.hexbitmask(affinity, get_nr_cpus()))
> +    return ",".join(str(hex(a)) for a in procfs.hexbitmask(affinity, utils.get_nr_cpus()))
>  
>  def ps_show_thread(pid, affect_children, ps, has_ctxt_switch_info, sock_inodes,
>                     sock_inode_re, cgroups, columns=None, compact=True):
> @@ -351,7 +331,7 @@ def ps_show_thread(pid, affect_children, ps, has_ctxt_switch_info, sock_inodes,
>                  irqs = procfs.interrupts()
>              users = irqs[tuna.irq_thread_number(cmd)]["users"]
>              for u in users:
> -                if u in get_nics():
> +                if u in utils.get_nics():
>                      users[users.index(u)] = "%s(%s)" % (
>                          u, ethtool.get_module(u))
>              users = ",".join(users)
> @@ -486,7 +466,7 @@ def do_ps(thread_list, cpu_list, irq_list, show_uthreads, show_kthreads,
>  
>  
>  def find_drivers_by_users(users):
> -    nics = get_nics()
> +    nics = utils.get_nics()
>      drivers = []
>      for u in users:
>          try:
> @@ -689,10 +669,10 @@ def main():
>          apply_config(args.profilename)
>  
>      elif args.command in ['include', 'I']:
> -        tuna.include_cpus(args.cpu_list, get_nr_cpus())
> +        tuna.include_cpus(args.cpu_list, utils.get_nr_cpus())
>  
>      elif args.command in ['isolate', 'i']:
> -        tuna.isolate_cpus(args.cpu_list, get_nr_cpus())
> +        tuna.isolate_cpus(args.cpu_list, utils.get_nr_cpus())
>  
>      elif args.command in ['run', 'r']:
>  
> diff --git a/tuna/utils.py b/tuna/utils.py
> new file mode 100644
> index 0000000..f55432d
> --- /dev/null
> +++ b/tuna/utils.py
> @@ -0,0 +1,28 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +# Copyright (C) 2024 John B. Wyatt IV
> +
> +import os
> +
> +import tuna.new_eth as ethtool
> +
> +# Collect a few globals and functions so they can be reused in other modules
> +nr_cpus = None
> +nics = None
> +
> +def get_nr_cpus():
> +    """ Get all cpus including disabled cpus """
> +    global nr_cpus
> +    if nr_cpus != None:

Really a nit: as a general standard, objects should be compared to None
using the "is" operator.

> +        return nr_cpus
> +    nr_cpus = os.sysconf('SC_NPROCESSORS_CONF')
> +    return nr_cpus
> +
> +def get_all_cpu_list():
> +    return list(range(get_nr_cpus()))
> +
> +def get_nics():
> +    global nics
> +    if nics != None:

Ditto.

> +        return nics
> +    nics = ethtool.get_active_devices()
> +    return nics
> -- 
> 2.48.1
>