Gitea's concurrency group did not serialise two runs on benjy: the second
run's scp failed with ETXTBSY on the binary the first was executing (safe,
it happened before the miner was touched, but the run was lost). The pause,
lock, measure and resume sequence now lives in bench-on-host.sh, executed
over one ssh call under flock on the host, with per-run binary and record
names so staging never collides.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CBgs2nSi4H2mdh8kD8vMX5
Two threads on one card overlap one thread's readback with the other's
dispatch, which is the bubble quantus/miner#4 and #5 target. Measuring it in
the harness first means #4 lands with a number instead of a hypothesis.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CBgs2nSi4H2mdh8kD8vMX5
quantus/miner#2. The measurement gate every kernel and submission change
passes before merge.
crates/bench-harness (lair-owned, never touched by origin merges):
- drives GpuEngine through MinerEngine, one worker thread per card, with
fixed timed windows after a warm-up; reports per-worker median MH/s and
spread and refuses (exit 5) when spread exceeds 2%
- captures nvidia-smi state (driver, power limit, draw, clock, temperature)
before and after, and refuses to run (exit 3) when the enforced power limit
is not the expected one, since that is the largest confound on these cards
- GPU/CPU parity on random jobs, same shape as engine-gpu's gpu_cpu_parity
example, exit 4 on any mismatch
- one JSON record per run (schema 1) plus a markdown summary on stdout
- build.rs embeds the commit like miner-cli's
.gitea/workflows/bench.yaml:
- runner containers on the GPU hosts have no device passthrough, so the
binary is built on cuda-13.0 (Fedora 43, matching the hosts; the rust
image is Fedora 44 and its binaries need a newer glibc) and executed on
the host over ssh as gitea_ci
- stops quantus-miner.service for the window and starts it again under a
trap; refuses to measure a card that is busy with the miner stopped
- benjy (4090, dedicated) by default; host, duration, runs, batch size and
workers are dispatch inputs; PRs touching engine or service crates trigger
it and get the summary as a comment
- one measurement per host at a time (concurrency group)
The stop/start sudoers grants were added to lair/quantus infra-setup.sh
(lair/quantus#5) and applied to benjy and quadbrat.
Origin coupling: one line in the workspace members list, marked.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CBgs2nSi4H2mdh8kD8vMX5
