Recent content on hacklog
I will present and discuss below three topics in Linux Storage/File System/Memory Management/BPF (LSFMMBPF) 2026. DAMON Updates: Tiering, Pagel Level Monitoring and DAMON-X Allowing NUMA hinting faults or alternatives to DAMON Data Access-aware Transparent Hugepages Detailed schedules and links to details of each topic can be found from this Google doc.
As today is the first day of 2026, I checked my open source commits statistics using my simple and buggy scripts. Similar statistics for 2024 is available at another post. Note that the script may have bugs, and numbers don’t tell everything. TL; DR In short, I made 2nd and 1st biggest changes to Linux kernel memory management subsystem among the 321 people, in terms of lines of changes…
In the coming second week of December, I will have one and three talks at at Open Source Summit (OSSummit) Japan and Linux Plumbers (LPC), respectively. In the Refereed track of LPC, I will introduce new DAMON features for page level and fleet wide data access monitoring. In the “Linux System Monitoring and Observability” micro conference of LPC, I will share history and limitations on…
I got a Macbook Pro. I was wondering if I can do kernel development on it since I recently learned that modern small computers are fast enough to be used for frequent kernel builds. I also heard a few of my previous colleague kernel developers use their Macbook for kernel builds. Unfortunately I cannot install Linux kernel on the laptop at the moment, though. I hence created a Debian13 VM on it…
A few weeks ago I heard modern normal computers can build kernel faster than I expected. My 10 years old personal laptop (Thinkpad X1) used to build a kernel per a couple of hours. The last time I built kernel on the laptop was about 8 years ago. Since then, I was always using only workstation or server level machines for building kernels. So I wanted to know how good modern normal desktop-level…
DAMON talk for Kernel Recipes 2025 has been scheduled. The title of the talk is “Overcoming Observer Effects in Memory Management with DAMON”. It will introduce DAMON at whole for wider audience.
DAMON talk for OSSummit North America 2025 has been accepted and scheduled. The title of the talk is “Self-Driving DAMON/S: Controlled and Automated Access-aware Efficient Systems”. It will present DAMON’s two auto-tuning features for access monitoring and access-aware system operations.
I will present and discuss about the current status and future plans of DAMON, and any requirements to DAMON for more access-aware memory management kernel subsystem of future in Linux Storage/File System/Memory Management/BPF (LSFMM+BPF) 2025. The title of the talks are “DAMON Updates and Plans: Monitoring Parameters Auot-tuning and Memory Tiering” and “DAMON Requirements for…
As today is the last day of 2024, I checked my open source commits statistics using my simple and buggy scripts. Similar statistics for 2023 is available at another post. Note that the script may have bugs, and numbers don’t tell everything. In short, I made 7th and 2nd biggest changes to Linux kernel memory management subsystem among the 340 people, in terms of lines of changes (2,347) and…
I will present DAMON in FOSDEM'25. The title of the talk is “DAMON: Kernel Subsystem for Data Access Monitoring and Access-aware System Operations”.
This post has migrated to https://damonitor.github.io/posts/damon_heatmap_logo/.
DAMON talk for OSSummit EU 2024 has accepted and scheduled. The talk will focus on use cases of DAMON for saving memory including those for real world products. The title of the talk is “DAMON Recipes: Ways to Save Memory Using a Linux Kernel Subsystem in the Real World”.
I will present and discuss about the current status and future plans of DAMON in Linux Storage/File System/Memory Management/BPF (LSFMM+BPF) 2024. The title of the talks is “DAMON updates and Plans: Automation of DAMON tuning, tiering, and VM guest scaling”. https://docs.google.com/spreadsheets/d/176LXLys9Uh6A-Eal2flrzcbUSJMUXGkGwyihr9jAAaQ/edit#gid=0
I started subscribing linux kernel mailing list with my gmail account in 2013. Dealing with the large amount of mails was not that easy, probably due to my poor setup and being lazy at trying more tools. In 2019, while returning from Linux Plumbers Conference, I read an LWN article saying Linus Torvalds is now considering unsubscribing the linux kernel mailing list, owing to the evolvement of the…
DAMON talk for OSSummit North America 2024 has been accepted and scheduled. The talk will present DAMOS auto-tuning and hopefully, more new DAMO features. The features are still under development, but hopefully, the power of presentation-driven development will make it. ;) Looking forward to meeting you there!
제 작은 취미 프로젝트[1]였던 Paul E. McKenney 의 책 한국어 번역이 약 8년 만에 소박한 이정표[2]를 완성했습니다. 매우 재미있고 유익한 여정이었습니다. [1] https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/perfbook.git/commit/?id=edbfcdee0460 [2] https://lore.kernel.org/perfbook/20240211175355.4986-1-sj38.park@gmail.com/
After about 8 years of progress on my little hobby project[1], the Korean translation of Paul E. McKenney ’s book, I’m marking it as completed a humble milestone[2]. It was a very fun and informative journey. [1] https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/perfbook.git/commit/?id=edbfcdee0460 [2] https://lore.kernel.org/perfbook/20240211175355.4986-1-sj38.park@gmail.com/
As today is the last day of 2023, I checked some open source commits statistics using my simple and buggy script, and github. Similar statistics for 2022 is available at another post. In short, I made 8th and 4th biggest changes to Linux kernel memory management subsystem among the 295 people, for lines of changes (1,910) and commits (66). For the Linux kernel whole tree, the numbers become 264th…
DAMON talk for OSSummit EU 2023 has accepted and scheduled. The talk will focus on its user-space tool, damo. It’s mainly for helping more audiences to digest the content easier, and also for accelerating the development of damo. By the time, hopefully the version of damo would reach to, or exceed 2.0.0, and newer interface and features will be introduced together. The title of the talk is…
This post has migrated to https://damonitor.github.io/posts/damon_publications_talks.
This post has migrated to https://damonitor.github.io/posts/damon_news.
I will present and discuss about the current status and future plans of DAMON in Linux Storage/File System/Memory Management/BPF (LSFMM+BPF) 2023. The title of the talks is “DAMON updates and future plans”. https://events.linuxfoundation.org/lsfmm/program/schedule-at-a-glance/
I will present DAMON, DAMOS, and DAMO in Open Source Summit North America 2023. The title of the talk is “DAMON, DAMOS, and DAMO: Kernel Subsystems and User-Space Tools for Data Access-Aware System Analysis/Optimizations”. https://sched.co/1K5HS
This post has migrated to https://damonitor.github.io/posts/damon_optimization_guide.
This post has migrated to https://damonitor.github.io/posts/damon_evaluation.
2022년 마지막 날을 맞아, 저의 간단하고 버그가 많은 스크립트와[1] github 을 통해 저의 오픈소스 커밋 통계를 내봤습니다. 리눅스 커널 통계 리눅스 커널의 메모리 관리 서브시스템과 커널 전체의 2022년 통계를 위해 제 버그 많은 스크립트를[1] 아래와 같이 돌려 봤습니다. 메모리 관리 서브시스템 2022년 한해, 305명의 사람들이 리눅스 커널 메모리 관리 서브시스템 개발에 참여해 81,631 라인의 변경을 2,135 개 커밋으로 만들었습니다. 변경한 라인 수와 커밋 갯수 기준으로 저는 그 305명 가운데 두번째와 (10,537 라인) 세번째로 (106 커밋) 큰 변경을 만들었군요.
As today is the last day of 2022, I checked some open source commits statistics using my simple and buggy script[1], and github. Linux kernel statistics I ran my buggy script[1] to show some 2022 statistics for memory management subsystem and whole tree of Linux kernel as below. Memory Management In 2022, 305 people participated in Linux kernel memory management subsystem development by making…
This post has migrated to https://damonitor.github.io/posts/damon_stat_2022.
Today is the 10th anniversary of my Linux kernel contribution. Including the tiny and trivial patch, I made 381 patches merged in the mainline during the 10 years. $ git log --author SeongJae --reverse commit cf174b0ef52ad8184779e1da4132e2d9d17247e5 Author: SeongJae Park <sj38.park@gmail.com> Date: Tue Oct 16 16:47:50 2012 +0900 staging: csr: csr_framework_ext_types.h: fix coding style Fix coding…
오늘은 제가 리눅스 커널에 처음 기여를 한지 10년이 되는 날입니다. 그 작고 사소했던 패치를 포함해, 지난 10년간 총 381개의 패치를 메인라인에 기여했네요. $ git log --author SeongJae --reverse commit cf174b0ef52ad8184779e1da4132e2d9d17247e5 Author: SeongJae Park <sj38.park@gmail.com> Date: Tue Oct 16 16:47:50 2012 +0900 staging: csr: csr_framework_ext_types.h: fix coding style Fix coding style of csr_framework_ext_types.h Signed-off-by: SeongJae Park…
I will present current status and future plans for DAMON in KernelSummit'22. The title of the talk is “Current Status and Future Plans of DAMON”. https://lpc.events/event/16/contributions/1224/
My paper introducing DAMON and related works for making Linux a more data access-aware operating system has been accepted to be presented by the HPDC'22. The title of the paper is “DAOS: Data Access-aware Operating System”.
Whenever reading the kernel development statistics report for each release from LWN, I wanted to scope it down to specific subsystems. For that, I wrote a script. Belows are the top 10 kernel hackers who contributed to the memory management subsystem of Linux kernel, sorted by number of commits and changed (added, deleted, or modified) lines, respectively. $ ./authors.py ~/linux --file mm/ --since…
record interesting papers that I (partially) read
I will present DAMON/DAMOS in KernelSummit'21. The title of the talk is “Writing a fine-grained access pattern-oriented lightweight kernel module using DAMON/DAMOS in 10 minutes”. https://linuxplumbersconf.org/event/11/contributions/984/
KernelSummit'21 에서 DAMON/DAMOS 를 발표하게 되었습니다. 발표 제목은 “Writing a fine-grained access pattern-oriented lightweight kernel module using DAMON/DAMOS in 10 minutes” 입니다. https://linuxplumbersconf.org/event/11/contributions/984/
This post is for recording some notes from a few OSDI'21 papers that I got fun. DMon: Efficient Detection and Correction of Data Locality Problems Using Selective Profiling https://www.usenix.org/system/files/osdi21-khan.pdf DMon is a compiler-based data locality optimization system. The approach is quite similar to that of daphicx or similar things. It injects data access profiling code in the…
리눅스 커널이 처음 공개된지 올해로 30년이 되었고, 이를 맞아 한 tag1 에서 리누스 토발즈와 인터뷰 를 했습니다. 분량이 많아 두 파트로 나눠 올렸는데요, 해당 매체에 허락을 받고 이곳에 그 중 두번째 파트의 번역을 올립니다. 아래 분들께서 오타 등을 찾고 글을 다듬는 걸 도와주셨습니다. 감사의 말씀을 전합니다. Jaehoon Kim Tag1 의 원본 글은 다음 링크에서 보실 수 있습니다: https://www.tag1consulting.com/blog/interview-linus-torvalds-open-source-and-beyond-part-2 첫번째 파트의 번역은 여기서 보실 수 있습니다. 오픈소스 프로젝트의 관리 JA: 우린 최근에 Drupal 을 만든 Dries Buytaert 와 이야기…
리눅스 커널이 처음 공개된지 올해로 30년이 되었고, 이를 맞아 tag1 에서 리누스 토발즈와 인터뷰 를 했습니다: https://www.tag1consulting.com/blog/interview-linus-torvalds-linux-and-git 분량이 길어 두 파트로 나눠 올라왔는데, 해당 매체에 허락을 받고 이곳에 그 중 첫번째 파트의 번역을 올립니다. 두번째 파트는 여기서 보실 수 있습니다. 아래 분들께서 오타 등을 찾고 글을 다듬는 걸 도와주셨습니다. 감사의 말씀을 전합니다. ganadist Jaehoon Kim 리눅스 커널 개발 Jeremy Andrews: 리눅스는 어디에나 사용되고 있고, 전체 오픈소스 세계에 영향을 끼쳤습니다. 물론, 처음부터 그런 건 아니었습니다.
2019-09-27 이후로 perfbook 번역을 멈췄었군요. 이제 perfbook 2nd 에디션도 나왔으니[0], 바닥부터 번역을 다시 시작해 봅니다[1]. 물론, 예전 번역본은 여전히 있습니다[2]. [0] https://mirrors.edge.kernel.org/.../perfbook/perfbook.html [1] https://github.com/sjp38/perfbook-ko_KR/commit/1c44ef30179b [2] https://github.com/sjp38/perfbook-ko_KR-pdf
I stopped translation of perfbook since 2019-09-27. Because the 2nd edition of perfbook is released[0], I’m starting the translation again[1], from the scratch. The old versions are still available, of course[2]. [0] https://mirrors.edge.kernel.org/.../perfbook/perfbook.html [1] https://github.com/sjp38/perfbook-ko_KR/commit/1c44ef30179b [2] https://github.com/sjp38/perfbook-ko_KR-pdf
This post has migrated to https://damonitor.github.io/posts/damon_profile_callstack_example.
차일 피일 미루고 있던 OSDI'20 발표 영상 비디오를 휴가 기간동안 하루 한편이라도 보기로 했습니다. A large scale analysis of hundreds of in-memory cache clusters at Twitter https://www.youtube.com/watch?v=OQtMM5vdhlI&feature=emb_title 트위터의 in-memory 캐시 시스템의 워크로드를 트레이스하고 그 특성을 분석한 논문입니다. 개인적으로 아래 내용이 흥미로웠습니다. 쓰기 리퀘스트가 많음. 각 오브젝트의 크기는 작아서 (중간값이 200 바이트), 오브젝트별 메타데이터 (64 바이트) 가 공간을 많이 차지함. 키의 크기가 밸류의 크기보다 그렇게 작지 않음. 트레이스 데이터는 github[1] 통해…
I set watching at least one OSDI'20 presentation video per day during the long vacation as one of my plans. A large scale analysis of hundreds of in-memory cache clusters at Twitter https://www.youtube.com/watch?v=OQtMM5vdhlI&feature=emb_title The authors traced and analyzed the workloads on the Twitter’s in-memory cache systems. To me, below findings were interesting. There are many write…
올해 초, 우연히 전자잉크 태블릿인 Remarkable 2 의 소개 영상 을 보게 되었습니다. 간단하지만 분명한 목표 (‘종이’와 같은 사용경험) 에 집중한 디자인과 기능이 무척 매력적으로 다가왔습니다. 망설이다 7월에 한번 더 사이트에 들어가 봤는데, 선주문 기간인데다 팬데믹 등의 영향으로 11월에야 배송된다고 하더군요. 한달 내로는 무료 반품도 된다길래 고민할 시간은 많으니 일단 지르고 고민해 보자는 생각으로 질렀습니다. 한참의 시간이 지나, 지난 월요일에 마침내 제품을 받게 되었습니다. 개인적으로 처음 구매해 본 전자잉크 기기인데, 이제 겨우 일주일 됐지만 제법 만족스럽게 사용 중입니다.
다양한 형태로 생각을 기록하고 가끔은 공유도 해왔습니다. 그 생각들을 오래도록 안전히 보관하고 싶었지만 몇차례 시행착오를 거치며 그게 쉽지 않음을 깨달았습니다. 시작은 일기장과 노트였습니다. 분실하기도 쉽고 구석에 쳐박아 두면 다시 볼일도 거의 없더군요. 클라우드 문서 서비스가 매력적이어 보였습니다. 하지만 영원한 건 없고 결국 그때 그때 흥하는, 또는 사용 가능한 서비스를 옮겨다녀야 하더군요. 그러다보니 서비스마다의 호환성이 문제가 됩니다. https://yargerdotblog.files.wordpress.com/2019/02/cloudmeme.jpg Hugo 와 같은 README 등 표준적 포맷의 plain text 기반 static site generator 를 사용하고 Git 으로 원격 repo 도…
This post has migrated to https://damonitor.github.io/posts/damon-tests_open_sourced.
My talk proposal to the Linux Kernel Summit of this year which is co-located with the Linux Plumbers Conference has accepted! Hope to (virtually) see you there. The title of the talk is, “DAMON: Data Access Monitoring Framework for Fun and Memory Management Optimizations”.
This post has migrated to https://damonitor.github.io/posts/damon_github_page/.
최근, Sphynx 빌드 시스템[1] 을 사용해 html 로 빌드한 리눅스 커널 문서를 Github page[2] 에 올리려 했습니다. DAMON[3] 문서를 어디서나 볼 수 있게 하려 함이었는데요. 업로드는 쉬웠습니다. 리포지토리 만들고, Sphynx 로 빌드된 Documentation/output/ 의 문서를 여기에 집어넣고 푸시했죠. 하지만, 테마가 적용되지 않아 보기 안좋더군요. Github 은 모든 Github page 들이 Jekyll[4] 에 기반하고 있다고 생각하며, Jekyll 에서는 _ 로 시작하는 이름의 모든 파일과 디렉토리가 특수하게 처리되기 때문에, Sphynx 에서 생성한 일부 디렉토리가 무시되고 있었습니다.