Laptop Mode Tools 1.72

What a way to make a gift! I’m pleased to announce the 1.72 release of Laptop Mode Tools. Major changes include the port of the GUI configuration utility to Python 3 and PyQt5. Some tweaks, fixes and enhancements in current modules. Extending {black,white}list of devices to types other than USB. Listing of devices by their devtype attribute. A filtered list of changes is mentioned below. For the full log, please refer to the git repository. [Read More]

Freezing of tasks failed

It is interesting how a user-space task could lead to hinder a Linux kernel software suspend operation. [11735.155443] PM: suspend entry (deep) [11735.155445] PM: Syncing filesystems ... done. [11735.215091] [drm:wait_panel_status [i915]] *ERROR* PPS state mismatch [11735.215172] [drm:wait_panel_status [i915]] *ERROR* PPS state mismatch [11735.558676] rfkill: input handler enabled [11735.608859] (NULL device *): firmware: direct-loading firmware rtlwifi/rtl8723befw_36.bin [11735.609910] (NULL device *): firmware: direct-loading firmware rtl_bt/rtl8723b_fw.bin [11735.611871] Freezing user space processes ... [11755.615603] Freezing of tasks failed after 20. [Read More]

Fixing Hardware Bugs

Bugs can be annoying. Especially the ones that crash or hang and do not have a root cause. A good example of such annoyance can be kernel bugs, where a faulty hardware/device driver hinders the kernel’s suspend/resume process. Because, as a user, while in the middle of your work, you suspend your machine hoping to resume your work, back when at your destination. But, during suspend, or during resume, randomly the bug triggers leaving you with no choice but a hardware reset. [Read More]

Linux IO + Memory + CPU Contention

I very recently met someone, and we had a good productive discussion on the features and (long standing) bugs of the Linux kernel. No doubt, Linux is the most featureful kernel in the market. Is also a lot appealing given its breadth of platform support. Of that discussion we had, it led about Linux’s behavior in tighter stressed scenarios where there is a lot of contention among the core subsystems. From the conversation, I got the feedback that perhaps the issue is no more valid. [Read More]

Linux Desktop in 2014

We are almost at the end of 2014. While 2014 has been a year with many mixed experiences, I think it does warrant one blog entry ;-) Recently, I’ve again started spending more time on Linux products / solutions, than spending time focused on a specfic subsystem. This change has been good. It has allowed me to re-cap all the advancements that have happened in the Linux world, umm… in the last 5 years. [Read More]

Power consumption on Linux 3.10

The power consumption on the Linux kernel 3.10 is pretty bad. On kernel 3.10, with the follwing config, the PowerTop results are: # # Timers subsystem # _CONFIG_TICKONESHOT=y _CONFIG_NO_HZCOMMON=y _# CONFIG_HZPERIODIC is not set _CONFIG_NO_HZIDLE=y _# CONFIG_NO_HZFULL is not set _CONFIG_NOHZ=y _CONFIG_HIGH_RESTIMERS=y PowerTOP v2.0 Overview Idle stats Frequency stats Device stats Tunables The battery reports a discharge rate of 28.0 W The estimated remaining time is 23 minutes Summary: 1785.5 wakeups/second, 0. [Read More]