One thing that caught my interest lately was the implementation of hash tables, particularly the algorithms we are currently using for calculating the hash value. In kmod we use Paul Hsieh’s hash function, self entitled superfast hash. I fell troubled with anything that entitles itself as super fast, especially given the benchmarks provided are from some years ago, with older CPUs.

After some time spent on benchmarking and researching I realized there were much more things to look after than just the hash function. With this post I try to summarize my findings, showing some numbers. However do take …

I’m back from USA after one week attending Linux Plumbers Conference. This was my first time in LPC, in which I was part of the CoreOS, talking about “From libabc to libkmod: writing core libraries”.

It was a very good experience and I’m glad to meet so many developers, both kernel and userspace hackers. Some of them I only knew from IRC, mailing-lists, etc and it was great time to share our experiences, discuss the current problems in Linux and even fix bugs :-). We seem finally to have reached a consensus on how module signing should be done …

Hey, this is my feedback of ELC 2012. If you didn’t read the first part, about ABS 2012, you can read the previous post first.

ELC is one of my favorite conferences as I can meet several talented people and have good talks about Linux in embedded devices. This time was not an exception and I enjoyed very much. The main reason I was there was because I was going to present kmod, the new tool to manage kernel modules. But that would be only on the last day of the conference. Let’s start from the beginning.

To …

Hey, kmod 3 is out. Really nice to finish this release. I was hoping to have it between the holidays, but there were some major bugs pending. It’s nice to see udev from git already using it instead of calling modprobe for each module. Kay reported a hundred less forks on bootup after start using libkmod and libblkid.

It’s nice too receive feedback about other architectures that we don’t have access, too. With kmod 3, sh4 joined the other architectures that were tested with kmod.

Since I’m already doing the announcements to the mailing lists, I …

So, in last post I said kmod 2 could be released sooner than expected if there were major bugs. Not as much as a surprise, there was 1: depending on the alias passed to the lookup function we were blocked iterating a list.

It’s now fixed in git tree. Thanks to Ulisses Furquim for fixing it and Dave Reisner for the bug report. We already have some other great stuff implemented so we’ll soon have another release.

Another great news is that now we have the maintainer of module-init-tools (Jon Masters) cooperating with us. We will discuss how …

For some weeks now I and Gustavo Barbieri at ProFUSION have been working on a new library and a set of tools, libkmod and kmod respectively. This is the announcement of its first public release.

Overview

The goal of the new library libkmod is to offer to other programs the needed flexibility and fine grained control over insertion, removal, configuration and listing of kernel modules. Using the library, with simple pieces of code it’s possible to interact with kernel modules and then there’s no need to rely on other tools for that. This is a thing lacking on …