Harry (Hyeonggon) Yoo
Posts
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112- Linux Kernel Developer @ Oracle (Linux Kernel MM) (2025.02 ~ Present)
- Reviewer for the Linux Slab & Reverse Mapping subsystem
- Former Intern @ NVIDIA, SK Hynix, Panmnesia (Security, MM and CXL)
- B.Sc. in Computer Science & Engineering, Chungnam National University (Class of 2025)
Opinions are my own.
My interests are:
Memory Management,
Computer Architecture,
Circuit Design,
Virtualization
Harry (Hyeonggon) Yoo
hyeyoo
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LostConnection
wagi@mastodon.socialI got ask how to get into kernel development. Basically asking for a starting point to work (simple bugs etc). I don't know a good answer and kernelknewbies seems also pretty outdated. Any ideas?
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Jonathan Corbet
corbet
It took a long time and over 60 articles but, at @lwn, we have finally managed to complete our reporting from the 2025 Linux Storage, Filesystem, Memory Management, and BPF Summit. If you want to know what is going on in those core parts of the kernel, this is the place to look.
We've put together an EPUB version of the whole set as well — good bedtime reading!
https://lwn.net/Articles/1026338/
We've put together an EPUB version of the whole set as well — good bedtime reading!
https://lwn.net/Articles/1026338/
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Petr Tesařík
ptesarik@infosec.exchangeIn case you want to join my company (#SUSE), we're looking for an #infrastructure engineer!
#FediHire
https://suse.wd3.myworkdayjobs.com/Jobsatsuse/job/Czech-Republic-EMEA/Senior-Software-Engineer--Core-Platforms-_71006946
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hyeyoo
Edited 27 days ago
How does the kernel manage LRU lists and perform memory reclaim when memory cgroup feature is enabled? I wrote an article to answer that question.
Memory Cgroup Naturalization in the Linux Kernel v3.3
https://vmscan.org/memory-cgroup-naturalization-in-the-linux-kernel-v33
In the early days, memory cgroup was “bolted onto” the memory management subsystem, using a double-LRU scheme: each page was linked to both global and per-memcg lists—leading to a moderate memory overhead and complicating reclaim logic.
Linux v3.3 changed that. Memory cgroups were fully integrated into the MM core, global LRU lists were removed on memcg-enabled systems, and global reclaim began walking memcg hierarchy and scanning the per-memcg LRU lists, scanning each group in proportion to its memory usage.
This reduced memory overhead and simplified the reclaim code. More details in the article!
Memory Cgroup Naturalization in the Linux Kernel v3.3
https://vmscan.org/memory-cgroup-naturalization-in-the-linux-kernel-v33
In the early days, memory cgroup was “bolted onto” the memory management subsystem, using a double-LRU scheme: each page was linked to both global and per-memcg lists—leading to a moderate memory overhead and complicating reclaim logic.
Linux v3.3 changed that. Memory cgroups were fully integrated into the MM core, global LRU lists were removed on memcg-enabled systems, and global reclaim began walking memcg hierarchy and scanning the per-memcg LRU lists, scanning each group in proportion to its memory usage.
This reduced memory overhead and simplified the reclaim code. More details in the article!
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Phoronix
phoronix@masto.aiLinux 6.15 Released With Continued Rust Integration, Bcachefs Stabilizing
As anticipated the Linux 6.15 kernel is out today in stable form. Linux 6.15 brings a lot of new hardware support, security improvements, various other kernel innovations, and more...
https://www.phoronix.com/news/Linux-6.15-Released
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printf of persia 🇺🇦🇨🇿👃💨
lkundrak@metalhead.clubthen: "when I grow up I'll be programming computers"
now: "i vibepirated code i wrote"
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Harry (Hyeonggon) Yoo
hyeyoo
Edited 2 months ago
Recently started learning how memory cgroup in the Linux kernel works, so started writing articles about it. The first posting for my English blog vmscan.org!
A brief look at memory cgroup controller introduced in the Linux kernel v2.6.25.
https://vmscan.org/a-brief-look-at-memory-cgroup-controller-introduced-in-linux-kernel-v2625
A brief look at memory cgroup controller introduced in the Linux kernel v2.6.25.
https://vmscan.org/a-brief-look-at-memory-cgroup-controller-introduced-in-linux-kernel-v2625
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@krzk @ljs
Me crying ever since I randomly picked MM in college :'(
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Of course, just kidding—it just takes a significant amount of time to even start reviewing when you look at complex subsystems. But no matter how complex the subsystem you're looking at is, as long as your curiosity doesn’t stop and you keep spending time on it, you’ll eventually get there.
And yeah, being good at using Git is such an important skill in a project with a long history (and being able to find and read old mailing list threads too...)
Me crying ever since I randomly picked MM in college :'(
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Of course, just kidding—it just takes a significant amount of time to even start reviewing when you look at complex subsystems. But no matter how complex the subsystem you're looking at is, as long as your curiosity doesn’t stop and you keep spending time on it, you’ll eventually get there.
And yeah, being good at using Git is such an important skill in a project with a long history (and being able to find and read old mailing list threads too...)
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Harry (Hyeonggon) Yoo
hyeyoo
Edited 2 months ago
I have been spending seven hours every Saturday studying the Linux kernel with a study group for years. It's been fun, but over time, I started to feel like I wasn’t spending my time wisely. I have to accept the fact that I don’t have enough time to regularly look at anything outside of MM.
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Harry (Hyeonggon) Yoo
hyeyoo
Edited 2 months ago
I tried GPT-o3 (which uses 'advanced reasoning') to review slab patches to see if it works, and it generated many false comments. :P Less advanced than I expected.
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