An interesting anecdote shared in today's

is word that Linux and Git creator Linus Torvalds switched his main rig over to an AMD Ryzen Threadripper.

At least for what he has said in the past, Linus has long been using Intel boxes given his close relationship with the company (and even close proximity to many of the Intel Portland open-source crew). In fact, he commented this is the first time in about fifteen years not using an Intel system as his primary machine. He made this interesting remark in the RC7 announcement:

In fact, the biggest excitement this week for me was just that I upgraded my main machine, and for the first time in about 15 years, my desktop isn't Intel-based. No, I didn't switch to ARM yet, but I'm now rocking an AMD Threadripper 3970x. My 'allmodconfig' test builds are now three times faster than they used to be, which doesn't matter so much right now during the calming down period, but I will most definitely notice the upgrade during the next merge window.

The

and the rest of the 3900 series line-up are incredibly great options for kernel developers and those frequently compiling large code-bases. He didn't mention the CPU in his prior Intel box, but he is seeing 3x faster builds.

With the upcoming

merge window in early June, his Threadripper system is sure to have a great workout.

This in turn is actually good news as well for AMD Ryzen Linux users: as Torvalds is constantly building the latest kernel code for mainline, he tends to shout quite publicly and loudly when any code breaks on his systems stemming from botched/poorly-tested pull requests... Thus with the extra and immediate exposure on Threadripper, he will hopefully be spotting any kernel-breaking regressions more quickly and who knows whatever other improvements he may be able to wrangle up as he's burning in his new system.

Introduced in the Linux 4.18 kernel was the

intended to yield faster user-space operations on per-CPU data. As covered during a presentation at this week's Open-Source Summit Europe, that system call is indeed providing performance wins while it's not widely utilized yet.

The restartable sequences system call allows for faster performance in per-CPU data updates from user-space for items like incrementing per-CPU counters, modifying data protected by per-CPU spinlocks, reading/writing per-CPU ring buffers, and similar operations while the kernel guarantees atomic behavior. The RSEQ system call was merged for Linux 4.18 while in the newly-released Linux 4.19 kernel the syscall is supported on ARM64 and other architectures.

There still is ongoing work for improving Restartable Sequences especially with utilizing this syscall from different key components in the Linux user-space, but it's looking like the performance benefits are worthwhile. Mathieu Desnoyers of EfficiOS presented at this week's Open-Source Summit Europe in Edinburgh where he covered this interesting kernel work. The benchmark results are what excited us the most:

Those wishing to learn more about the ongoing RSEQ syscall and weren't able to make it to Edinburgh for the event, Desnoyers' slide deck can be viewed

(PDF). There is also another presentation by Mathieu back from

with more background information on this system call if you are interested in more reading this weekend.