Cross-process zero-copy NVMM IPC on Jetson — dma-buf fd passing, NvBufSurfaceImport, lock-free pool

Cross-Process Zero-Copy on Jetson: dma-buf fds, NvBufSurfaceImport, and a Cache-Line-Padded Pool

Two processes on a Jetson, one camera frame in NVMM (GPU memory), no copies. The kernel does the heavy lifting via dma-buf fds; SCM_RIGHTS carries the fd across the process boundary; NvBufSurfaceImport reconstructs the surface on the consumer side; a cache-line-padded ring of atomic ref-counts keeps fan-out coherent without locks. With benchmark numbers and a Godbolt-runnable demo of the SCM_RIGHTS pattern.

April 25, 2026 · 22 min · Pavel Guzenfeld
Cleaning Up, Pipelining, and Bake-Testing the STM32H750 Tracker

Cleaning Up, Pipelining, and Bake-Testing the STM32H750 Tracker

A sequel to the first STM32H750 tracker post. After the C++ port was proven in production, I spent a week of evenings cutting dead vendor code, splitting the algorithm out to host for unit tests, wiring the LCD SPI through DMA to let the CPU run the tracker in parallel with the blit, unlocking the camera’s real frame rate, chasing a subtle BB-drift bug back to a too-wide SAD search, and finally building an offline A/B harness that compares SAD, NCC, and MOSSE on four synthetic scenarios so the next tracker port is a data decision, not a vibes one.

April 23, 2026 · 17 min · Pavel Guzenfeld
Building a Template-Matching Tracker on an STM32H750

Building a Template-Matching Tracker on an STM32H750: What Worked, What Didn't

A long, honest retrospective on turning a WeAct STM32H750 board, a cheap OV7725 IR camera, and an Xbox controller into a live template-matching tracker. Every dead end, every wrong assumption, every fix — and what I’d do differently next time.

April 21, 2026 · 23 min · Pavel Guzenfeld
Persistent SMB Shares on Linux

Persistent SMB Shares on Linux — From Manual Mount to Automount on Access

A step-by-step guide to mounting SMB/CIFS network shares on Linux — from one-off access in a file manager to persistent fstab entries with systemd automount that connect only when needed and gracefully handle VPN disconnects.

March 24, 2026 · 7 min · Pavel Guzenfeld
Linux Multi-Monitor Setup with xrandr

Linux Multi-Monitor Setup — A Practical Guide to xrandr, Lid Close, and Persistent Configuration

A hands-on walkthrough of configuring multiple monitors on Linux — from identifying displays with xrandr, turning off the laptop screen, ignoring lid close, to making it all survive a reboot. Every command explained.

March 23, 2026 · 9 min · Pavel Guzenfeld