Drew Fustini pdp7

Tenstorrent on upstream lists, 2025-11 through 2026-05

A six-month survey of upstream Linux kernel, QEMU, and OpenSBI development by Tenstorrent contributors, intended as source material for a NotebookLM "deep dive" audio podcast about the team. Drew Fustini's own patch series (CBQRI, Ssqosid, RQSC, kernel-side IOMMU bindings, and his maintainer-hat pull requests) are deliberately excluded: those are the listener's own work and would dilute the focus on coworkers.

The period covered is roughly 2025-11-09 through 2026-05-09, the six

OpenSBI Mailing List Digest, 2026-Jan through 2026-May

Source: ~/opensbi-mail-archive/2026-{January,February,March,April,May}.txt. Approximately 526 messages across five months, with ~76 from Anup Patel (de-facto maintainer) leading review, and substantial new platform/feature work landing or in flight.

The digest is organized by topic. The first section is a deep dive on Tenstorrent contributors, since the reader is at Tenstorrent and asked for detail there. Subsequent sections cover the broader upstream picture so a NotebookLM "deep dive" episode has enough scaffolding to draw connections, debates, and architectural threads.

1. Tenstorrent contributors

name	Drew Fustini - writing style and voice
description	How Drew writes on lkml/linux-riscv (cover letters, replies, sign-offs); use to match his tone in drafts of emails, commit messages, and cover letters
type	user
originSessionId	49cba08f-3549-46fe-86fe-0fe3c60829bb

Studied from a sample of Drew's lore.kernel.org emails. Index covers 447 emails from fustini April 2020 - July 2025; ~75-80% are replies, the rest cover letters / standalone patches / pull requests. Style is remarkably stable across the 5-year span and across employer changes (gmail -> beagleboard -> baylibre -> tenstorrent -> pdp7.com / fustini@kernel.org).

Tone and persona

MPAM QoS features and MPAM support in Linux resctrl

A technical survey of Arm's Memory Partitioning and Monitoring (MPAM) extension and the multi-year effort to expose it through the Linux resctrl filesystem. Written against this tree (Linux v7.0-base, RISC-V CBQRI development branch); file paths and message-IDs cite primary sources where possible.


	pdp7@thelio:~/dev/linux$
	pdp7@thelio:~/dev/linux$
	pdp7@thelio:~/dev/linux$ cat ./build-matrix.sh
	#!/bin/bash
	# build-matrix.sh - 0day-style strict build matrix for the QoS series
	# Runs each configuration sequentially with -j16 (full 16-core machine).
	# Logs go to build-matrix/logs/<name>.log so you can tail -f the active build.

	set -euo pipefail

	#!/usr/bin/env bash
	# Refresh a semcode database: source code (current HEAD or branches),
	# lore archives + new shards, then regenerate vector embeddings.
	#
	# Usage: update-semcode.sh [options]
	#
	# Options:
	# -s, --source <dir> source tree to index (default: cwd)
	# -d, --database <dir> db dir or its parent (default: same as --source)
	# --branches <list> comma-separated branches to update (uses --update-branches)


	Patch sizes vs resctrl norms

	┌───────────────────────────────────────────────┬──────────────────────┬───────────────────┬──────────────────┐
	│ Series │ Patches │ Median │ Max lines/patch │
	│ │ │ lines/patch │ │
	├───────────────────────────────────────────────┼──────────────────────┼───────────────────┼──────────────────┤
	│ Recent fs/resctrl (last 30) │ small │ ~30 │ ~50 │
	│ │ fixes/refactors │ │ │
	├───────────────────────────────────────────────┼──────────────────────┼──────────────────

	ptybb ptyq5 ptyuf ptyz9 tty63 ttye2 ttysc ttyx6
	debian@lpi4amain:~$ ls /dev/^C
	debian@lpi4amain:~$ dmesg
	[ 0.000000] Booting Linux on hartid 3
	[ 0.000000] Linux version 7.0.0-rc3-next-20260313 (pdp7@thelio) (Ubuntu clang version 18.1.3 (1ubuntu1), Ubuntu LLD 18.1.3) #1554 SMP PREEMPT Sun Mar 15 11:40:21 PDT 2026
	[ 0.000000] random: crng init done
	[ 0.000000] Machine model: Sipeed Lichee Pi 4A
	[ 0.000000] SBI specification v2.0 detected
	[ 0.000000] SBI implementation ID=0x1 Version=0x10004
	[ 0.000000] SBI TIME extension detected

	/home/dfustini/.tenstorrent-venv/bin/python boot.py --boot --l2cpu 0 --opensbi_bin fw_jump.bin --opensbi_dst 0x400030000000 --rootfs_dst 0x4000e5000000 --kernel_bin Image --kernel_dst 0x400030200000 --dtb_bin blackhole-card.dtb --dtb_dst 0x400030100000
	Starting PCI link reset on BH devices at PCI indices: 0
	Waiting for up to 2 seconds for asic to come back after reset
	Config space reset completed for device 0
	Finishing PCI link reset on BH devices at PCI indices: 0
	Writing OpenSBI to 0x400030000000
	Writing Kernel to 0x400030200000
	Writing dtb to 0x400030100000
	Setting clock to 200
	Setting clock to 1750