Most of us learn Emacs one motion at a time – C-f for a character, M-f for a word, C-n for a line. Useful, but those commands don’t know anything about the structure of your code. Emacs has a whole other family of commands that operate on balanced expressions and definitions instead, and once they become muscle memory they’re hard to give up. Lisp hackers know these commands intimately – they’re the foundation paredit builds on. What’s less appreciated is that they work in plenty of other lan... Read more ›
Remote and disaggregated memory tiers expand the effective memory capacity of analytical database engines, but they also reshape the cost structure of out-of-memory query processing. When an operator spills beyond local DRAM, moving pages to remote memory incurs both data-transfer time and a fixed round-trip latency per transfer. Classical operator analyses and buffer-allocation heuristics primarily target disk spilling by minimizing total I/O v... Read more ›
Multi-agent LLM systems -- coding agents, devops agents, document agents -- now routinely run several agents in parallel against the same git tree, Kubernetes cluster, or document. As soon as two of them mutate shared state, they enter the regime classical concurrency control has studied for decades, but classical mechanisms fit LLM agents poorly. A single agent transaction spans minutes of inference, read sets are broad and opaque rather than s... Read more ›
The folks who 'grok' Emacs aren't wizards. They don't learn Emacs, per se, but instead they learn the handful of built-in commands for asking Emacs about Emacs.... Read more ›
Empowering Student Debugging in Parallel Programming with Execution Traces and Large Language Models
Concurrent programming is a core component of Computer Science curricula, yet remains notoriously difficult for students to master due to its inherent complexity and the nondeterministic nature of concurrency bugs such as deadlocks and race conditions. In this work, we present ParaView, an educational tool designed to help students understand, debug, and correct concurrency issues in parallel programs written in C/C++. ParaView provides transpar... Read more ›
Distributed systems handle adversarial nodes through redundancy, which imposes a significant performance overhead. In blockchain systems, Byzantine fault-tolerant state-machine replication (BFT-SMR) is the replicated service that totally orders client transactions before execution. While prior research has primarily focused on designing novel consensus algorithms with improved performance, recent studies have shown that further gains can be achi... Read more ›
I have written about pdf-tools quite a few times – it’s a fantastic Emacs package for viewing and annotating pdfs without leaving the comfort of Emacs. It is not ideal, though – or at least, not ideal for me. One feature of Emacs I often use is the scroll-other-window command (bound to C-M-v), and its sibling scroll-other-window-down (C-M-S-v). They are extremely useful for example when reading documentation or watching live Markdown preview, and I wish they worked with the TeX and pdf-tools ... Read more ›
Heterogeneous LLM serving stacks split scheduling into two layers that optimize in isolation: model routers pick a model from quality and cost signals while ignoring instance load, and serving load balancers optimize queues while ignoring quality. We present RouteBalance, a serving-aware scheduling layer that fuses both into a single online assignment over concrete model instances, jointly trading off quality, latency, and cost. A batched in-pro... Read more ›
Dense Eisenstein--Jacobi (EJ) networks are degree-six algebraic interconnection networks whose finite quotient geometry is naturally represented by a hexagonal axial-coordinate ball. This paper studies non-redundant one-to-all broadcast repair in the dense EJ network generated by $\alpha=(t+1)+t\omega$, where $t$ is the network diameter. We propose EJ-MOEM, a multi-orientation edge-minimum repair method that evaluates a constant-size family of h... Read more ›
Reinforcement learning for service orchestration has been the subject of sustained research for over a decade, yet it is not used in production at scale. The usual explanation is that learned controllers degrade under delayed and noisy telemetry, workload shifts, and uncontrolled tenants. We test whether existing evidence supports that explanation. We evaluate three highly influential RL-based orchestration systems spanning resource allocation, ... Read more ›
In the literature on mutual exclusion, bounded bypass has been used for a long time as a strengthening of starvation-freedom, but, to the best of our knowledge, it still lacks a satisfying definition as a liveness property on its own. Moreover, we have encountered MUTEX protocols for which this notion needs to be slightly weakened in order to be met. To solve these issues, we first provide a formal definition of bounded bypass (that also correct... Read more ›
On March 8, 2026, British Columbia moved their clocks to a year-round Pacific Daylight Savings Time. In March, they did the spring forward one hour with their clocks to UTC-7, but they won't fall back to UTC-8 in November. Going forward, the UTC offset for America/Vancouver timezone is permanently UTC-7.Let's use this as an opportunity to talk about date and time zone storage. In the most basic examples, the default is to store the UTC value, then calculate local time relative to UTC. However... Read more ›
Video diffusion has quickly grown into a key generative serving workload, yet producing each clip demands many denoising iterations over large spatio-temporal latents, which puts low-latency inference out of reach on a single device. A denoising step is therefore typically distributed across multiple accelerators, and TPU sub-slices have become an attractive and practical fabric for doing so. Current auto-parallel systems, however, search almost... Read more ›
When the Next Step Is Not One Step: Distribution-Aware Execution Modeling for Concurrent Go Programs
Training a model to predict the next step in a concurrent program is harder than it looks: two runs of the same program from the same trace prefix can produce different next events, both valid, because the scheduler is nondeterministic. A model trained against a single label is learning to guess one outcome of a random process. We turn this around and use the nondeterminism as a training signal. We run each program many times, aggregate the obse... Read more ›
Modern blockchain state management faces a critical scalability bottleneck: maintaining cryptographic commitments over hundreds of millions of entries becomes computationally prohibitive. Ethereum's transition to Verkle Trees: polynomial commitment accumulators reducing proof sizes from O(width * depth) to O(depth) via constant-size IPA vector commitments, is a critical step toward stateless operation. Yet, current implementations exhibit pathol... Read more ›
The post examines Ponytail, a popular AI coding “skill”, and argues that its benchmarked benefits appear to come largely from encouraging terse, YAGNI-style responses rather than from any deeper engineering value. By showing that a simple prompt can match or beat Ponytail on its own benchmark, it makes a broader case for treating prompt-based tools with scepticism unless their claims are backed by robust evaluation. Read more ›
Multi-agent LLM systems share state through memory stores, vector indices, and tool registries. We model such sharing as long-running read-generate-write operations under deterministic-generation semantics -- the regime durable-execution engines enforce by deterministic replay -- and formalize four concurrency anomalies in TLA+: stale-generation, phantom-tool, causal-cascade, and tool-effect reordering, structural analogues of classical isolatio... Read more ›
Gaussian networks are degree-four symmetric interconnection networks defined over residue classes of Gaussian integers. Earlier work showed that when the generator $\alpha=a+bi$ satisfies $\gcd(a,b)=1$, the real and imaginary dimensions directly form two edge-disjoint Hamiltonian cycles. A later construction extended the result to the non-coprime case $\gcd(a,b)=d>1$, but its proof used long node-sequence tables and separate odd/even cases for $... Read more ›
Urban territories face growing tensions between increasing digital demand, limited resources, and socially constrained built environments. Although distributed computing paradigms such as edge and fog computing are widely presented as solutions for reducing latency and energy dissipation, the scientific literature largely overlooks where such infrastructures can be physically and socially deployed within cities, and typically neglects urban cons... Read more ›