Just implemented heatmap visualization for each DAMON's access pattern snapshot. It is inpsired by Lorenzo's page layout idea[1].

Someone might be able to hack DAMON for generating page types snapshot instead of access pattern snapshot, and reuse some of the heatmap visualization code, if they are getting bored and get plenty spare time ;)

[1] https://social.kernel.org/notice/Ao0id4tH8kLlNztK0u

#linux #kernel #damon #damo

@ljs @jann re: real time physical memory layout, I replied to @ljs via mail, but TL; DR: No. But if no real page granularity is required, I think we can make a fun hack using DAMON's adaptive regions adjustment mechanism[1].

[1] https://docs.kernel.org/mm/damon/design.html#adaptive-regions-adjustment

Posted "a guide to DAMON tuning and results interpretation for hot pages" to mailing lists[1]. Hopefully this will help better tuning of DAMON for given purposes. Cross-posted it to the blog[2] too, for people who prefer rendered page, and possible future revisions.

[1] https://lore.kernel.org/20241108232536.73843-1-sj@kernel.org
[2] https://damonitor.github.io/posts/damon_tuning_guide_for_hot_pages/

#linux #kernel #damon #hotpage_detection #tuning #guide

Just released damo v2.5.4[1]. The major new feature in this release is recency/temperature histogram visualization[2] of DAMON's access pattern snapshots.

[1] https://github.com/damonitor/damo/blob/v2.5.4/release_note#L4
[2] https://github.com/damonitor/damo/blob/v2.5.4/USAGE.md#access-report-styles

#linux #kernel #damon #damo

I'm still looking for a space on `damo` USAGE.md[1] for a formal documentation of DAMOS auto-tuning usage. Because I'm only continue failing it everyday, just wrote a blog post for an informal usage of it with examples: https://damonitor.github.io/posts/damo_autotune_example/

[1] https://github.com/damonitor/damo/blob/next/USAGE.md

#linux #kernel #damon #damo #damos #auto-tuning

Outreachy is getting squeezed financially from reduced funding related to diversity programs and reduced funding for open source orgs. Can you help us spread the word about how important the program is and help us connect to folks who might contribute funding?

https://www.outreachy.org/blog/2024-08-14/outreachy-needs-your-help/

@outreachy
#outreachy

Just realized the new member looks similar to the penguin of FB kernel team logo hat I found from https://opensource.fb.com/linux/ (file name: kernel-team-logo.svg)

RE: https://social.kernel.org/objects/11adc48b-1b76-4d76-8e86-c6c89d87d895

The CFP for the Containers devroom at @fosdem 2025 is now open! https://discuss.linuxcontainers.org/t/fosdem-2025-containers-devroom-call-for-papers/21956

Thanks @jejb for restoring sanity!

https://lore.kernel.org/all/e7d548a7fc835f9f3c9cb2e5ed97dfdfa164813f.camel@HansenPartnership.com/

@ljs I'm glad that my script helped you in some way :)

Several Russian developers lose kernel maintainership status

https://lwn.net/Articles/995186/ #LWN

The bubble is not popped yet. The 30-days PyPI downloads of 'damo' has doubled (8,000 -> 16,000) again, about ten days after the last doubling.

#linux #kernel #damon #damo #pypistats

RE: https://social.kernel.org/objects/d7273398-9f50-43bc-97c8-14673a13d783

DAMON project site's main page (https://damonitor.github.io) was redirecting[1] to a personal blog post, with its hidden real main page[2]. Now DAMON has its own project blog, and does not redirect[3] to personal blog anymore.

[1] https://github.com/damonitor/damonitor.github.io/blob/230038cfd5b85783bc6391f675fab66abe81eb79/index.html
[2] https://damonitor.github.io/_index.html
[3] https://github.com/damonitor/damonitor.github.io/commit/817d619090d8abb02e6a4020ff5d0b9664c6464c

#linux #kernel #damon #blog

I posted[1] an RFC patchset for DAMON debugfs interface removal a few days ago. Unless someone objects, the change will be merged soon, maybe into v6.14-rc1.

[1] https://lore.kernel.org/20241015175412.60563-1-sj@kernel.org

#linux #kernel #damon

@kernellogger It failed by default, as below:

$ bash kcbench -b -i 1 -j $(nproc --all)
[NOTE] Downloading source of Linux 5.15; this might take a while...
Processor:           QEMU Virtual CPU version 2.5+ [40 threads]
Cpufreq; Memory:     Unknown; 63163 MiB
Linux running:       6.12.0-rc2-mm-unstable-damon+ [x86_64]
Compiler:            gcc (Debian 12.2.0-14) 12.2.0
Linux compiled:      5.15.0 [.../.cache/kcbench/linux-5.15]
Config; Environment: defconfig; CCACHE_DISABLE="1"
Build command:       make vmlinux
Run 1 (-j 40):

Compilation failed. Aborting kcbench. Command used for compilation:
CCACHE_DISABLE="1" make --silent -C '.../.cache/kcbench/linux-5.15' O='/tmp/kcbench.yjn7s1H3h/worker-0/' -j '40' vmlinux
Tail from the output:
CCACHE_DISABLE="1" make --silent -C '.../.cache/kcbench/linux-5.15' O='/tmp/kcbench.yjn7s1H3h/worker-0/' -j '40' vmlinux
.../.cache/kcbench/linux-5.15/scripts/extract-cert.c: In function ‘display_openssl_errors’:
.../.cache/kcbench/linux-5.15/scripts/extract-cert.c:46:9: warning: ‘ERR_get_error_line’ is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
   46 |         while ((e = ERR_get_error_line(&file, &line))) {
      |         ^~~~~
[...]
cc1: all warnings being treated as errors
[...]
make: *** [Makefile:219: __sub-make] Error 2

After adding -s 5.17 following the workaround from @klausman [1], it succeed.

$ bash kcbench -b -i 1 -j $(nproc --all) -s 5.17
[NOTE] Downloading source of Linux 5.17; this might take a while...
[...]
Linux compiled:      5.17.0 [.../.cache/kcbench/linux-5.17]
Config; Environment: defconfig; CCACHE_DISABLE="1"
Build command:       make vmlinux
Run 1 (-j 40):       65.73 seconds / 54.77 kernels/hour [P:2858%, 45 maj. pagefaults]

[1] https://social.kernel.org/notice/AmuC8cjqppYS6XduT2

After about ten days from the last posting[1] of damo [2] monthly downloads record, the count has doubled (4,000 -> 9,000) again. The time for doubling the count has been reduced from 18 months to 7 months, then to 10 days this time.

Because daily stat graphs on PyPI are not very convenient for monthly download stats, I plotted the 'rolling 30-day downloads' count. It shows this might be a temporal bubble that will pop soon. But, doubling is doubling. I'll seize tonight :D

[1] https://social.kernel.org/notice/AmYHJtlc5aI4ObXnKS
[2] https://github.com/damonitor/damo

#linux #kernel #damon #damo #pypistats

An official video is also uploaded on YouTube: https://youtu.be/mRU1ZeNB9WY?feature=shared

#linux #kernel #damon #linuxplumbers

RE: https://social.kernel.org/objects/f6b89ea2-239f-40c8-b910-3eb3ef48c66b

At OSSummit Europe last month, I and Honggyu Kim presented[1] a few DAMON recipes including those for memory auto-scaling and CXL memory tiering. The video is now available at YouTube[2].

[1] https://sched.co/1ej2S
[2] https://youtu.be/xKJO4kLTHOI?feature=shared

#linux #kernel #damon #ossummit #asv2 #hmsdk

@qyousef @gregkh @oleksandr @axboe @kernellogger @ljs @vbabka It's clear we have many rooms to improve, and I'm grateful for these constructive discussions. I'd like to say, though, that the stable trees stably work pretty well for some use cases including my previous experiences at Amazon Linux (https://github.com/amazonlinux/linux), which is assumed to be one of the major kernels for AWS.

Again, we shouldn't be fully convinced about the current status since we have much room to improve. I just wanted to say the current status is not really completely broken, and appreciate people including the maintainers and people proposing improvements.