User Mode Linux 5.2

User Mode Linux 5.2 User Mode Linux version 5.2 has been uploaded to Debian Unstable and will soon be available on the supported architectures. This upload took more time than usual as I ran into a build time failure caused by newer PCAP library. Thanks to active upstream developers, this got sorted out quick. In the longer run, we may have a much better fix for it. What is User Mode Linux a. [Read More]

Bpfcc New Release

BPF Compiler Collection 0.11.0 bpfcc version 0.11.0 has been uploaded to Debian Unstable and should be accessible in the repositories by now. After the 0.8.0 release, this has been the next one uploaded to Debian. Multiple source respositories This release brought in dependencies to another set of sources from the libbpf project. In the upstream repo, this is still a topic of discussion on how to release tools where one depends on another, in unison. [Read More]
Linux  BCC  BPFCC  Tracing  eBPF 

Cross Architecture Linux Containers

Linux and ARM With more ARM based devices in the market, and with them getting more powerful every day, it is more common to see more of ARM images for your favorite Linux distribution. Of them, Debian has become the default choice for individuals and companies to base their work on. It must have to do with Debian’s long history of trying to support many more architectures than the rest of the distributions. [Read More]

Linux Desktop Usage 2019

If I look back now, it must be more than 20 years since I got fascinated with GNU/Linux ecosystem and started using it. Back then, it was more curiosity of a young teenager and the excitement to learn something. There’s one thing that I have always admired/respected about Free Software’s values, is: Access for everyone to learn. This is something I never forget and still try to do my bit. [Read More]

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]