PowerTOP Release Notes

v2.16-rc3

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

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
• 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

• 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 --batch mode numeric safety and i18n issues
• Fixed halfdelay timeout clamping to valid ncurses range

Translations

• 17 previously missing source files added to translation coverage
• All .po files 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
• Zentaro Kavanagh