Visiting Scholar at Purdue University, West Lafayette, Indiana State (2024.01.04 ~ 2024.02.24)
Good bye Purdue University!

It has been so intense, now suffering from jet lag and getting back to real life.

Was working out today wearing this tshirt, suddenly someone asked me "You use Linux? I use Arch by the way..."

At this point obviously I'm here to drink more

First week at purdue

My friend told me to play Minecraft together (It's been 4 years since last played) but I can't because Microsoft threw away my Mojang account 😠 😠

```As of December 18, 2023, the post-migration process for Mojang accounts has officially ended```

Yesterday, my internship finally finished. It was fun and inspiring to look at a project (QEMU) other than Linux, and learn how PCIe/CXL/ACPI/UEFI works in general.

Now trying to do some work (a little) on CXL emulation in QEMU, though I'm not sure how far I want to pursue as my heart is still in MM.

https://lore.kernel.org/linux-cxl/20231222090051.3265307-1-42.hyeyoo@gmail.com/T

This link captures the confusion about how to pronounce "fsck":

https://lwn.net/Articles/190223/

Here's the truth. Ted Kowalski, username frodo, may he rest in peace, was the original author, just down the hall from my office in Murray Hill, and his name for the program had a 'u' where there is now an 's'. Management made him change it for distribution, but they couldn't make him change his pronunciation.

Interesting post from the Android Rust compiler team:

https://android-developers.googleblog.com/2023/12/faster-rust-toolchains-for-android.html

Seems to line up with my benchmarks for performing a lot of the same optimization techniques to LLVM and clang and it is cool to see the amount of savings that this translates to for CI. Reminds me that I should look at integrating my kernel.org LLVM builds into tuxmake so that we can use them with tuxsuite…

when @ljs is low on cat

At OSS Festival last week (in Seoul)

War and Peace

How QR codes are made:

Shared bicycles (not a biker gang)

the number of slab patches in this cycle is quite larger than usual...

#Linux #Kernel patch review process finally moving on from mailing lists

Hey #Linux #Kernel people. Last year we had the first #Kernel Devroom at #FOSDEM. And we're running the #Kernel Devroom for #FOSDEM in 2024 as well!

#FOSDEM 2024 is taking place over the weekend of the 3 & 4 February in Brussels, Belgium!

It is a wonderful event that's very close to my and a lot of people's hearts!

Join @rppt, Daniel Borkmann, and @stgraber, and myself and make this another great #FOSDEM!

We're very excited for your submissions!

https://lists.fosdem.org/pipermail/fosdem/2023q4/003536.html

For the 2023 ClangBuiltLinux meetup, I decided to revisit my benchmarks comparing how building LLVM with different optimizations such as LTO, PGO, and BOLT can impact how fast it can build Linux kernels:

https://github.com/ClangBuiltLinux/cbl-meetup-2023/blob/9b399fe8f3b886d549105a82068e3a441e496b46/nathan_making_llvm_faster_with_build_time_optimization_technologies.pdf

TL;DR: PGO and BOLT can give huge wins, LTO not so much.

It was pretty wild to see how much PGO made a difference, almost twice as fast in some cases... The kernel.org LLVM toolchains I provide are built with PGO and BOLT for this reason:

https://mirrors.edge.kernel.org/pub/tools/llvm/

I WILL (NEVER) DRINK AGAIN

Hmm, I'm having difficulty understanding how interrupts from PCIe devices (with MSI-X support) can be distributed to different processors.

Only an address (to an Local APIC) can be assigned to an interrupt vector?

Yes, you heard it right, we're moving away from patches sent via email.

The fax number you should use from now on is 1-900-555-1212.