Linux Kernel Developer: Steven Rostedt

  • linux kernel developer

    Linux kernel developer Steven Rostedt maintains the Real Time Stable releases of the Linux kernel.

    Linus Torvalds recently released version 4.16 of the Linux kernel. These releases typically occur every nine to ten weeks, and each one contains the work of more than 1,600 developers representing over 200 corporations, according to the 2017 Linux Kernel Development Report, written by Jonathan Corbet and Greg Kroah-Hartman. In this series, we’re highlighting some of the developers who contribute to the kernel.

    Steven Rostedt, Open Source Programmer at VMware, maintains the Real Time Stable releases of the Linux kernel, among other things. Rostedt is one of the original developers of the PREEMPT_RT patch and began working on it in 2004 with the goal of turning Linux into a real-time designed operating system. He is also the main author, developer, and maintainer of Ftrace, a tool designed to help developers find what is going on inside the kernel. According to the Ftrace wiki, the tool can be used for debugging or analyzing latencies and performance issues that take place outside of user-space.

    Linux kernel dev

    Steven Rostedt

    Additionally, this past year, Rostedt found time to speak at various events and serve on The Linux Foundation’s technical advisory board. Here are Rostedt’s responses to our questions.

    Linux Foundation: What role do you play in the community and what subsystem(s) do you work on?

    Steven Rostedt: I partake in a lot of the Linux Foundation events as well as Kernel Recipes, Linux Plumbers, sometimes Linux Tag and other events. I’m on The Linux Foundation’s Technical Advisory Board (TAB) and was on the Linux Plumbers programming committee. I’m an Open Source advocate and try to communicate to people what that means. I maintain the Real Time Stable releases, and the Ftrace (Linux kernel tracer) subsystem, as well as ktest, localmodconfig, and Ftrace tools like trace-cmd and KernelShark.

    Linux Foundation: What have you been working on this year? / What’s one way you have contributed to the 4.8 to 4.13 releases?

    Rostedt: I’ve been working on having ftrace trace init functions in both the main kernel core as well as in modules. Between 4.8 and 4.13, I rewrote the function tracing trigger code to be able to be expanded and used to enable function filtering for tracing on modules before they are loaded.

    Linux Foundation: What do you think the kernel community needs to work on in the upcoming year?

    Rostedt: I think more focus should be on eBPF and helping it be easier to use as well as having an eye on security. Running a VM within the kernel can be very dangerous, and people need to use caution and be extra careful during development.

    Linux Foundation: Why do you contribute to the Linux kernel?

    Rostedt: Because it is the one place that you have total control over your computer.

    At the recent Embedded Linux Conference, Rostedt presented a session on “Maintaining a Real Time Stable Kernel,” in which he explained what’s required to maintain a stable RT tree, which is a bit different from maintaining a normal stable tree. In this talk, he covered various tools that can be used and described the current tests performed to ensure that the RT stable kernel is fully functional.

    You can learn more about the Linux kernel development process and read more developer profiles in the full report. Download the 2017 Linux Kernel Development Report now.

    The post Linux Kernel Developer: Steven Rostedt appeared first on The Linux Foundation.

Tmux Commands

screen and tmux

A comparison of the features (or more-so just a table of notes for accessing some of those features) for GNU screen and BSD-licensed tmux.

The formatting here is simple enough to understand (I would hope). ^ means ctrl+, so ^x is ctrl+x. M- means meta (generally left-alt or escape)+, so M-x is left-alt+x

It should be noted that this is no where near a full feature-set of either group. This - being a cheat-sheet - is just to point out the most very basic features to get you on the road.

Trust the developers and manpage writers more than me. This document is originally from 2009 when tmux was still new - since then both of these programs have had many updates and features added (not all of which have been dutifully noted here).

Action tmux screen
start a new session tmux OR
tmux new OR
tmux new-session
re-attach a detached session tmux attach OR
tmux attach-session
re-attach an attached session (detaching it from elsewhere) tmux attach -d OR
tmux attach-session -d
screen -dr
re-attach an attached session (keeping it attached elsewhere) tmux attach OR
tmux attach-session
screen -x
detach from currently attached session ^b d OR
^b :detach
^a ^d OR
^a :detach
rename-window to newname ^b , <newname> OR
^b :rename-window <newn>
^a A <newname>
list windows ^b w ^a w
list windows in chooseable menu ^a "
go to window # ^b # ^a #
go to last-active window ^b l ^a ^a
go to next window ^b n ^a n
go to previous window ^b p ^a p
see keybindings ^b ? ^a ?
list sessions ^b s OR
tmux ls OR
tmux list-sessions
screen -ls
toggle visual bell ^a ^g
create another window ^b c ^a c
exit current shell/window ^d ^d
split window/pane horizontally ^b " ^a S
split window/pane vertically ^b % ^a |
switch to other pane ^b o ^a <tab>
kill the current pane ^b x OR (logout/^D)
collapse the current pane/split (but leave processes running) ^a X
cycle location of panes ^b ^o
swap current pane with previous ^b {
swap current pane with next ^b }
show time ^b t
show numeric values of panes ^b q
toggle zoom-state of current pane (maximize/return current pane) ^b z
break the current pane out of its window (to form new window) ^b !
re-arrange current panels within same window (different layouts) ^b [space]
Kill the current window (and all panes within) ^b killw [target-window]