PowerTOP Release Notes
v2.16
User-visible enhancements and changes
New tunables
The following sysfs tunables have been added (sourced from the
clr-power-tweaks curated list):
| Tunable | sysfs path | Suggested value |
|---|---|---|
| VM dirty ratio | /proc/sys/vm/dirty_ratio
| 50
|
| Transparent hugepage scan sleep | /sys/kernel/mm/transparent_hugepage/khugepaged/scan_sleep_millisecs
| 30000
|
| Framebuffer cursor blink | /sys/devices/virtual/graphics/fbcon/cursor_blink
| 0
|
| KSM sleep interval | /sys/kernel/mm/ksm/sleep_millisecs
| 4000
|
| KSM batch size | /sys/kernel/mm/ksm/pages_to_scan
| 1000
|
| Autogroup scheduling | /proc/sys/kernel/sched_autogroup_enabled
| 0
|
| Intel P-state minimum performance | /sys/devices/system/cpu/intel_pstate/min_perf_pct
| 50
|
| Network default qdisc | /proc/sys/net/core/default_qdisc
| fq
|
| Intel ITMT (Turbo Boost Max 3.0) | /proc/sys/kernel/sched_itmt_enabled
| 1
|
| Intel energy performance bias | /sys/devices/system/cpu/cpu*/power/energy_perf_bias
| balance-performance
|
| Intel energy performance preference | /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
| balance_performance
|
| Intel Xe GPU power profile | /sys/class/drm/card*/device/tile*/gt*/freq0/power_profile
| power_saving
|
| Enable Audio codec power management | /sys/module/snd_hda_intel/parameters/power_save
| 1
|
| AMD GPU panel power savings | /sys/class/drm/*/amdgpu/panel_power_savings
| 2
|
Wildcard sysfs paths (e.g. cpu*) are now handled natively — PowerTOP
applies the tunable to all matching sysfs files and reports Good only when
all of them are already at the suggested value.
Display / UI
- GPU tab (Intel Xe): progress bar scale now always shows the true maximum
value right-aligned, suppressing any overlapping tick label - GPU tab: frequency bars now start at 0 instead of the hardware minimum,
giving a correct visual baseline - GPU tab: replaced
>/<policy markers with a four-segment colour bar
(bold green = floor, green = active, yellow = headroom, dim = beyond policy) - GPU tab: C0/C6 idle bars merged into a single two-colour bar
(red = busy/C0, bright green = idle/C6) since C0 is derived from C6 - GPU tab: active xe power profile displayed on the Power Overview section
- GPU tab: only shown on systems with Intel Xe GPU and xe hwmon present
- CPU Frequency Stats tab: redesigned with progress bars, corrected bar
width and spacing, and fixed C0 active column misalignment in Idle stats - CPU Frequency Stats tab: empty cores are skipped in display
- Show "Preparing to take measurements" message during the initial
one-second measurement so the screen is no longer blank at startup - Vertical scrollbar added to tab content panes
- Scroll-down capped at content extent to prevent over-scrolling
- Terminal resize (KEY_RESIZE / SIGWINCH) now handled correctly while
PowerTOP is running - Notification system redesigned to use the status bar instead of
overlaying content - Tab bar and bottom line now correctly fill the full terminal width
Reports
- HTML and CSV output: fixed escaping and i18n issues
- Markdown report output format added (
--output=file.md)
Correctness / stability fixes
--calibrate: display power control now uses sysfs DRM DPMS directly,
falling back to xset only if needed — works on X11, Wayland, and headless- Fixed three memory leaks found by Valgrind (power meters, tuning
window, wakeup tab window) - Fixed double-free in devfreq cleanup
- Fixed sysfs residency overflow in Intel GPU reporting
- Fixed RAPL division-by-zero and improved error handling
- Fixed Bluetooth byte-counter logic and removed deprecated tooling
- Added near-zero division guards for AHCI, ALSA, and RAPL power
calculations - Fixed
--batchmode numeric safety and i18n issues - Fixed halfdelay timeout clamping to valid ncurses range
- Fixed null pointer dereference when accessing first CPU in some configs
- Fixed potential memory leak in GPU handler initialisation
Translations
- 17 previously missing source files added to translation coverage
- All
.pofiles regenerated; format-specifier changes (%s→{})
applied mechanically across all 11 languages
New command-line options
--once: take a single measurement and exit--auto-tune-dump: run auto-tune and dump results without
interactive display
Thanks
We thank the following external contributors who submitted patches for this release:
- Anthony Ruhier
- George Burgess IV
- Jaroslav Škarvada
- Johannes Truschnigg
- Pascal Nasahl
- Renat Sabitov
- rottenpants466
- Simon Howard
- Steven Rostedt
- vallode
- Zentaro Kavanagh