My defaults are set for Linux Kernel development, but I have been in Qemu land lately and these values make it easier to format.
set shiftwidth=4
set expandtab
set tabstop=4
retab
Qemu code format in vim
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Tracing how much time the kernel spends in a function
Using ebpf and the bpftrace command line utility, you can perform simple reporting on function calls. Here’s an example:
Continue readingSelf hosting and installing from pip repos
I have an application that I want to share with my team. Fortunately, we have a shared server, so it is pretty easy to do so: if I put a file in /usr/local/bin it can A) be executed by anyone on the server and B) will not interfere with RPM packages. But, I do potentially want to put this code on other machines as well, so I am going to buld it as a pip package, upload it to a team repo (apache HTTPD instance on this machine) and then install it from pip as root.
Continue readingfunction tracing mctp-pcc
While it is tempting to use printk or pr_info when coding in order to trace function in the Linux kernel calls, it turns out that there os a; ready a utility to simplify that. Here are the steps I used to enable ftrace for mcpt-pcc and figuring out where a function call stack ended (in the middle of a debugging session where I had broken it)
Continue readingUsing bpftrace for PCC traffic
The following command will print a stack trace whenever pcc_send_data is called.
sudo bpftrace -e 'f:pcc_send_data{print(kstack())}'Tools First
I have wasted a lot of time as a developer waiting for long running processes to complete. Whether it is a Linux Kernel compile, and Ansible Playbook tearing down and recreating a system on a remote server, or a gitlab pipeline building and testing code, the common problem is that my head is in the problem being addressed there, but I cannot do anything to verify hypotheses until the process completes. I often get distracted while waiting, and find that what could have been a 5 minute turn around has become a 2 hour turn around.
Continue readingFind files to download from Apache default pages
Apache provides a pretty standard screen to display directoyr contents if you do not provide any mods. We post artifacts up to a local server that I later need to download. Here are my hacky notes using command line utilities. I probably will convert this to python next.
Continue readingChord Analysis of All the Things You Are
Eventually I want to be able to smoothly recall the chords at speed. However, when memorizing them, it helps to have a series of mnemonics, and to chunk them together. Just as you practice a song slow before you play it fast, you memorize the chords slow.
Here is my analysis of “All the Things You Are.”
Continue readingMemorizing Chord Changes
I have been working on memorizing chords for a bunch of Standards and originals. It helps tremendously. A couple things that have worked for me:
Continue readingQuery FreeIPA by manager
A recent question lead me down a rabbit hole: how can we list the people that report up to George Slate? While we should be able to query this from LDAP, it seems to be shut off. However, using FreeIPA’s HTTP API, we can, if you know what you are doing. I do…