Tootfinder

As we’re landing, crew asks everyone to stay seated so paramedics can get into the back of the plane. Seatbelt sign goes off, 5 people in my section promptly stand up and start yanking luggage from the overhead bins. Some bins left open when crew scolds people back to their seats.

This looks helpful: #rstats #optimization

@…
'Im Nirgendwo' 'in the nowhere'
It might look like a "normal" hiking photo. But that day I hiked into an area where I didn't see nor hear anybody for quite some hours!
Shortly after I took this photo, I reached a spot where I just stopped, looked around and - except for the trail - everything was just …

Projector is in place. Not as dumb as I usually like. Has an android OS and a Netflix app and things instead of just a HDMI input. But it has HDMI input too.
Screen is 1.9m wide by .92 high which is a 2.15m screen measured across the diagonal like they usually do.
Projection is keyed quite drastically with the right hand side being shrunk down vertically to square the image, which I suspect means pretty radically reduced resolution on the right hand side of the screen.
Maybe I could attach it to the bottom of the overhead cupboards more squarely onto the wall than the shelf is? Worth a though.
But working well. Will be even better when the main bedroom media PC arrives.

Had a fun time talking about my tiny CM system at @…. Lots of good questions and discussion.
It’s pretty well baked now, as ever more to do but keen to find more users for feedback and discussion.
Check out its revamped website:

Un Momento 🕰️
一瞬 🕰️
📷 Zeiss Ikon Super Ikonta 533/16
🎞️ Lucky SHD 400
#filmphotography #Photography #blackandwhite

ProphetKV: User-Query-Driven Selective Recomputation for Efficient KV Cache Reuse in Retrieval-Augmented Generation
Shihao Wang, Jiahao Chen, Yanqi Pan, Hao Huang, Yichen Hao, Xiangyu Zou, Wen Xia, Wentao Zhang, Haitao Wang, Junhong Li, Chongyang Qiu, Pengfei Wang
https://arxiv.org/abs/2602.02579 https://arxiv.org/pdf/2602.02579 https://arxiv.org/html/2602.02579
arXiv:2602.02579v1 Announce Type: new
Abstract: The prefill stage of long-context Retrieval-Augmented Generation (RAG) is severely bottlenecked by computational overhead. To mitigate this, recent methods assemble pre-calculated KV caches of retrieved RAG documents (by a user query) and reprocess selected tokens to recover cross-attention between these pre-calculated KV caches. However, we identify a fundamental "crowding-out effect" in current token selection criteria: globally salient but user-query-irrelevant tokens saturate the limited recomputation budget, displacing the tokens truly essential for answering the user query and degrading inference accuracy.
We propose ProphetKV, a user-query-driven KV Cache reuse method for RAG scenarios. ProphetKV dynamically prioritizes tokens based on their semantic relevance to the user query and employs a dual-stage recomputation pipeline to fuse layer-wise attention metrics into a high-utility set. By ensuring the recomputation budget is dedicated to bridging the informational gap between retrieved context and the user query, ProphetKV achieves high-fidelity attention recovery with minimal overhead. Our extensive evaluation results show that ProphetKV retains 96%-101% of full-prefill accuracy with only a 20% recomputation ratio, while achieving accuracy improvements of 8.8%-24.9% on RULER and 18.6%-50.9% on LongBench over the state-of-the-art approaches (e.g., CacheBlend, EPIC, and KVShare).
toXiv_bot_toot

ZOR filters: fast and smaller than fuse filters
Antoine Limasset
https://arxiv.org/abs/2602.03525 https://arxiv.org/pdf/2602.03525 https://arxiv.org/html/2602.03525
arXiv:2602.03525v1 Announce Type: new
Abstract: Probabilistic membership filters support fast approximate membership queries with a controlled false-positive probability $\varepsilon$ and are widely used across storage, analytics, networking, and bioinformatics \cite{chang2008bigtable,dayan2018optimalbloom,broder2004network,harris2020improved,marchet2023scalable,chikhi2025logan,hernandez2025reindeer2}. In the static setting, state-of-the-art designs such as XOR and fuse filters achieve low overhead and very fast queries, but their peeling-based construction succeeds only with high probability, which complicates deterministic builds \cite{graf2020xor,graf2022binary,ulrich2023taxor}.
We introduce \emph{ZOR filters}, a deterministic continuation of XOR/fuse filters that guarantees construction termination while preserving the same XOR-based query mechanism. ZOR replaces restart-on-failure with deterministic peeling that abandons a small fraction of keys, and restores false-positive-only semantics by storing the remainder in a compact auxiliary structure. In our experiments, the abandoned fraction drops below $1\%$ for moderate arity (e.g., $N\ge 5$), so the auxiliary handles a negligible fraction of keys. As a result, ZOR filters can achieve overhead within $1\%$ of the information-theoretic lower bound $\log_2(1/\varepsilon)$ while retaining fuse-like query performance; the additional cost is concentrated on negative queries due to the auxiliary check. Our current prototype builds several-fold slower than highly optimized fuse builders because it maintains explicit incidence information during deterministic peeling; closing this optimisation gap is an engineering target.
toXiv_bot_toot

from my link log —
Eliminate branches by melding IR instructions.
https://arxiv.org/abs/2512.22390
saved 2026-01-01 https://dotat.at/:/J3PP5.html

Eliminate Branches by Melding IR Instructions
Branch mispredictions cause catastrophic performance penalties in modern processors, leading to performance loss. While hardware predictors and profile-guided techniques exist, data-dependent branches with irregular patterns remain challenging. Traditional if-conversion eliminates branches via software predication but faces limitations on architectures like x86. It often fails on paths containing memory instructions or incurs excessive instruction overhead by fully speculating large branch bodi…

Last workout of the year.

Fast Sparse Matrix Permutation for Mesh-Based Direct Solvers
Behrooz Zarebavami, Ahmed H. Mahmoud, Ana Dodik, Changcheng Yuan, Serban D. Porumbescu, John D. Owens, Maryam Mehri Dehnavi, Justin Solomon
https://arxiv.org/abs/2602.00898 https://arxiv.org/pdf/2602.00898 https://arxiv.org/html/2602.00898
arXiv:2602.00898v1 Announce Type: new
Abstract: We present a fast sparse matrix permutation algorithm tailored to linear systems arising from triangle meshes. Our approach produces nested-dissection-style permutations while significantly reducing permutation runtime overhead. Rather than enforcing strict balance and separator optimality, the algorithm deliberately relaxes these design decisions to favor fast partitioning and efficient elimination-tree construction. Our method decomposes permutation into patch-level local orderings and a compact quotient-graph ordering of separators, preserving the essential structure required by sparse Cholesky factorization while avoiding its most expensive components. We integrate our algorithm into vendor-maintained sparse Cholesky solvers on both CPUs and GPUs. Across a range of graphics applications, including single factorizations, repeated factorizations, our method reduces permutation time and improves the sparse Cholesky solve performance by up to 6.27x.
toXiv_bot_toot

Trans people are incredible, strong, beautiful, and absolutely bring so much love and strength to our world.
:bisexual_pride: 🏳️‍⚧️ :genderfluid_flag: :nonbinary_flag: :heart_trans: 🏳️‍🌈
I wholeheartedly, unapologetically, and forever believe that #TransRightsAreHumanRights.
Always, forever, endlessly, trans people are real, valuable, and human in every way…

Some City Some Nature VII 🏙️🪾
一些城一些自然 VII 🏙️🪾
📷 Nikon F4E
🎞️ Fujifilm NEOPAN SS, expired 1993
#filmphotography #Photography #blackandwhite

A day after part of a missile fired by the United States hit their village, landing just meters from its only medical facility,
the people of Jabo in northwestern Nigeria are in a state of shock and confusion.
Suleiman Kagara, a resident of this quiet and predominantly Muslim farming community in Tambuwal district of Sokoto state, told CNN he heard a loud blast and saw flames as a projectile flew overhead at around 10 p.m. on Thursday.
Soon after, it came crashing down, expl…

Fear and confusion in Nigerian village hit in US strike, as locals say no history of ISIS in area
A day after part of a missile fired by the United States hit their village, landing just meters from its only medical facility, the villagers of Jabo in northwest Nigeria are in a state of shock and confusion.

#silentsunday
66 Geese

The sign is a lie (and they knew that advance: train goes only to Köln), but still on my way to #FOSDEM.
Happy any time to talk about #CoAP, #CBOR,

*A powerful FLOOF blocks your way*

Different Corners III ▶️
不同的角落 III ▶️
📷 Nikon F4E
🎞️ Fujifilm NEOPAN SS, expired 1993
#filmphotography #Photography #blackandwhite

Free Open-Source Whistleblower Platform Without Self-Hosting
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Free Open-Source Whistleblower Platform Without Self-Hosting | Hush Line
Hush Line is a free & open-source whistleblower platform that provides secure, anonymous tip lines with no self-hosting, maintenance, or technical overhead.

On my way from Ansbach to #39c3. See you soon!
After 15 years of Chaos events, I've forgotten my DECT phone for the first time 🙈
So this year I'm trying out @… SIP and can be reached at 2120.

@…
Saw 3 whistle ducks fly overhead while on a walk this morning.
My elderly mind went off on a tangent so I did bit of mods to your duck.
Behold the whistle duck in even more poorly drawn glory..
When did they add AI to paint? Damn thing kept trying to do things to the drawing . And they really screwed up transparency!!

#SilentSunday
Geese. December 2025.

Entry to an exhibition for kids at Munich‘s „Haus der Kunst“
#München #art #museum

BE NOT AFRAID

Scaling Vision Transformers: Evaluating DeepSpeed for Image-Centric Workloads
Huy Trinh, Rebecca Ma, Zeqi Yu, Tahsin Reza
https://arxiv.org/abs/2602.21081 https://arxiv.org/pdf/2602.21081 https://arxiv.org/html/2602.21081
arXiv:2602.21081v1 Announce Type: new
Abstract: Vision Transformers (ViTs) have demonstrated remarkable potential in image processing tasks by utilizing self-attention mechanisms to capture global relationships within data. However, their scalability is hindered by significant computational and memory demands, especially for large-scale models with many parameters. This study aims to leverage DeepSpeed, a highly efficient distributed training framework that is commonly used for language models, to enhance the scalability and performance of ViTs. We evaluate intra- and inter-node training efficiency across multiple GPU configurations on various datasets like CIFAR-10 and CIFAR-100, exploring the impact of distributed data parallelism on training speed, communication overhead, and overall scalability (strong and weak scaling). By systematically varying software parameters, such as batch size and gradient accumulation, we identify key factors influencing performance of distributed training. The experiments in this study provide a foundational basis for applying DeepSpeed to image-related tasks. Future work will extend these investigations to deepen our understanding of DeepSpeed's limitations and explore strategies for optimizing distributed training pipelines for Vision Transformers.
toXiv_bot_toot

Workout of the day.

It's Friday the 13ᵗʰ, post your sleep paralysis demons.
Mine is kinda cute :3

Drinking my black coffee and thinking of the post @… just wrote about coffee that you should read (https://schafe-sind-bessere-rasenmaehe

Flock of Pelicans flying over the beach. Moonstone Beach, Cambria, California, USA. May, 2023. OM System OM-1 M.Zuiko 12-40 F2.8. #moonstonebeach #pelican #birds

Some City Some Nature IV 🏙️🪾
一些城一些自然 IV🏙️🪾
📷 Zeiss IKON Super Ikonta 533/16
🎞️ Lucky SHD 400 (6x6)
#filmphotography #Photography #blackandwhite

Worked on some more #Gentoo global #jobserver goodies today.
Firstly, Portage jobserver support patch: #PyTest jobs will also be counted towards total job count.
Again, it's not a perfect solution, but it works reasonably. The plugin still starts -n jobs as specified by the arguments, but it acquired job tokens prior to executing every test, therefore delaying actual testing until tokens are available. It doesn't seem to cause noticeable overhead either.

Some City Some Nature VI 🏙️🪾
一些城一些自然 VI 🏙️🪾
📷 Zeiss IKON Super Ikonta 533/16
🎞️ Lucky SHD 400
#filmphotography #Photography #blackandwhite

Workout of the day.

For #footpathfriday , here's a nice path I'd say.
This is taken from a bike&hike right after the bike-part and thus the start of a very nice autumn hike last year. When I took this photo, I didn't know - and not even expect how well the rest of the day would be 🙂
Enjoy
#mountains

Workout of the day.

Some City Some Nature II 🏙️🪾
一些城一些自然 II 🏙️🪾
📷 Nikon F4E
🎞️ ERA 100, expired 1993
#filmphotography #Photography #blackandwhite

Workout of the day.

Workout of the day.

HALO: A Fine-Grained Resource Sharing Quantum Operating System
John Zhuoyang Ye, Jiyuan Wang, Yifan Qiao, Jens Palsberg
https://arxiv.org/abs/2602.07191 https://arxiv.org/pdf/2602.07191 https://arxiv.org/html/2602.07191
arXiv:2602.07191v1 Announce Type: new
Abstract: As quantum computing enters the cloud era, thousands of users must share access to a small number of quantum processors. Users need to wait minutes to days to start their jobs, which only takes a few seconds for execution. Current quantum cloud platforms employ a fair-share scheduler, as there is no way to multiplex a quantum computer among multiple programs at the same time, leaving many qubits idle and significantly under-utilizing the hardware. This imbalance between high user demand and scarce quantum resources has become a key barrier to scalable and cost-effective quantum computing.
We present HALO, the first quantum operating system design that supports fine-grained resource-sharing. HALO introduces two complementary mechanisms. First, a hardware-aware qubit-sharing algorithm that places shared helper qubits on regions of the quantum computer that minimize routing overhead and avoid cross-talk noise between different users' processes. Second, a shot-adaptive scheduler that allocates execution windows according to each job's sampling requirements, improving throughput and reducing latency. Together, these mechanisms transform the way quantum hardware is scheduled and achieve more fine-grained parallelism.
We evaluate HALO on the IBM Torino quantum computer on helper qubit intense benchmarks. Compared to state-of-the-art systems such as HyperQ, HALO improves overall hardware utilization by up to 2.44x, increasing throughput by 4.44x, and maintains fidelity loss within 33%, demonstrating the practicality of resource-sharing in quantum computing.
toXiv_bot_toot

Prune, Don't Rebuild: Efficiently Tuning $\alpha$-Reachable Graphs for Nearest Neighbor Search
Tian Zhang, Ashwin Padaki, Jiaming Liang, Zack Ives, Erik Waingarten
https://arxiv.org/abs/2602.08097 https://arxiv.org/pdf/2602.08097 https://arxiv.org/html/2602.08097
arXiv:2602.08097v1 Announce Type: new
Abstract: Vector similarity search is an essential primitive in modern AI and ML applications. Most vector databases adopt graph-based approximate nearest neighbor (ANN) search algorithms, such as DiskANN (Subramanya et al., 2019), which have demonstrated state-of-the-art empirical performance. DiskANN's graph construction is governed by a reachability parameter $\alpha$, which gives a trade-off between construction time, query time, and accuracy. However, adaptively tuning this trade-off typically requires rebuilding the index for different $\alpha$ values, which is prohibitive at scale. In this work, we propose RP-Tuning, an efficient post-hoc routine, based on DiskANN's pruning step, to adjust the $\alpha$ parameter without reconstructing the full index. Within the $\alpha$-reachability framework of prior theoretical works (Indyk and Xu, 2023; Gollapudi et al., 2025), we prove that pruning an initially $\alpha$-reachable graph with RP-Tuning preserves worst-case reachability guarantees in general metrics and improved guarantees in Euclidean metrics. Empirically, we show that RP-Tuning accelerates DiskANN tuning on four public datasets by up to $43\times$ with negligible overhead.
toXiv_bot_toot

Different Corners XI ▶️
不同的角落 XI ▶️
📷 Nikon F4E
🎞️ Rollei RPX 400
#filmphotography #Photography #blackandwhite

Workout of the day.

Different Corners IX ▶️
不同的角落 IX ▶️
📷 Nikon F4E
🎞️ Rollei RPX 400
#filmphotography #Photography #blackandwhite

Fork, Explore, Commit: OS Primitives for Agentic Exploration
Cong Wang, Yusheng Zheng
https://arxiv.org/abs/2602.08199 https://arxiv.org/pdf/2602.08199 https://arxiv.org/html/2602.08199
arXiv:2602.08199v1 Announce Type: new
Abstract: AI agents increasingly perform agentic exploration: pursuing multiple solution paths in parallel and committing only the successful one. Because each exploration path may modify files and spawn processes, agents require isolated environments with atomic commit and rollback semantics for both filesystem state and process state. We introduce the branch context, a new OS abstraction that provides: (1) copy-on-write state isolation with independent filesystem views and process groups, (2) a structured lifecycle of fork, explore, and commit/abort, (3) first-commit-wins resolution that automatically invalidates sibling branches, and (4) nestable contexts for hierarchical exploration. We realize branch contexts in Linux through two complementary components. First, BranchFS is a FUSE-based filesystem that gives each branch context an isolated copy-on-write workspace, with O(1) creation, atomic commit to the parent, and automatic sibling invalidation, all without root privileges. BranchFS is open sourced in https://github.com/multikernel/branchfs. Second, branch() is a proposed Linux syscall that spawns processes into branch contexts with reliable termination, kernel-enforced sibling isolation, and first-commit-wins coordination. Preliminary evaluation of BranchFS shows sub-350 us branch creation independent of base filesystem size, and modification-proportional commit overhead (under 1 ms for small changes).
toXiv_bot_toot

Towards Efficient Data Structures for Approximate Search with Range Queries
Ladan Kian, Dariusz R. Kowalski
https://arxiv.org/abs/2602.06860 https://arxiv.org/pdf/2602.06860 https://arxiv.org/html/2602.06860
arXiv:2602.06860v1 Announce Type: new
Abstract: Range queries are simple and popular types of queries used in data retrieval. However, extracting exact and complete information using range queries is costly. As a remedy, some previous work proposed a faster principle, {\em approximate} search with range queries, also called single range cover (SRC) search. It can, however, produce some false positives. In this work we introduce a new SRC search structure, a $c$-DAG (Directed Acyclic Graph), which provably decreases the average number of false positives by logarithmic factor while keeping asymptotically same time and memory complexities as a classic tree structure. A $c$-DAG is a tunable augmentation of the 1D-Tree with denser overlapping branches ($c \geq 3$ children per node). We perform a competitive analysis of a $c$-DAG with respect to 1D-Tree and derive an additive constant time overhead and a multiplicative logarithmic improvement of the false positives ratio, on average. We also provide a generic framework to extend our results to empirical distributions of queries, and demonstrate its effectiveness for Gowalla dataset. Finally, we quantify and discuss security and privacy aspects of SRC search on $c$-DAG vs 1D-Tree, mainly mitigation of structural leakage, which makes $c$-DAG a good data structure candidate for deployment in privacy-preserving systems (e.g., searchable encryption) and multimedia retrieval.
toXiv_bot_toot

Metropolitana VII - 🆙 🆙 🆙
城 VII - 🆙 🆙 🆙
📷 Pentax MX
🎞️ Ilford Pan 100
#filmphotography #Photography #blackandwhite

Metropolitana VII - Markings 💮
城 VII - 印记 💮
📷 Pentax MX
🎞️ Ilford Pan 100
#filmphotography #Photography #blackandwhite

Rare Colours Blues IV🔷🔷
稀有的色彩蓝 IV🔷🔷
📷 Pentax MX
🎞️ Harman Phoenix 200 II (FF)
#filmphotography #Photography #Art

Metropolitana VI - Asymmetry ✅
城 VI - 非对称 ✅
📷 Pentax MX
🎞️ Ilford Pan 100
#filmphotography #Photography #blackandwhite

Different Corners VII ▶️
不同的角落 VII ▶️
📷 Nikon F4E
🎞️ Fujifilm NEOPAN SS, expired 1993
#filmphotography #Photography #blackandwhite

Metropolitana IV 🏯
城 IV 🏯
📷 Pentax MX
🎞️ Ilford Pan 100
#filmphotography #Photography #blackandwhite

Metropolitana II🔶
城 II🔶
📷 Pentax MX
🎞️ Ilford Pan 100
#filmphotography #Photography #blackandwhite

Urbanity - Cloud Four ☁️
城市化 - 四云 ☁️
📷 Pentax MX
🎞️ Ilford Pan 100
#filmphotography #Photography #blackandwhite

Different Corners VI ▶️
不同的角落 VI ▶️
📷 Nikon F4E
🎞️ Fujifilm NEOPAN SS, expired 1993
#filmphotography #Photography #blackandwhite