ppopp-experiments
GitHub用于设计或审查PPoPP论文的实验评估,确保并发正确性与可扩展性。涵盖速度曲线、强弱扩展、NUMA/GPU效应、竞争微基准及方差分析,要求提供严谨的正确性论证和诚实的强基线对比。
Trigger Scenarios
Install
npx skills add brycewang-stanford/Awesome-Journal-Skills --skill ppopp-experiments -g -y
SKILL.md
Frontmatter
{
"name": "ppopp-experiments",
"description": "Use when designing or auditing a PPoPP paper's evaluation, covering the twin bar of concurrency correctness and measured scalability — speedup curves, strong vs weak scaling, core\/thread sweeps, NUMA and GPU effects, contention microbenchmarks plus real workloads, variance and measurement hygiene, and honest strong baselines."
}
PPoPP Experiments
Design the evaluation to clear PPoPP's twin bar: the contribution must be correct under concurrency and measurably scalable. A speedup with no correctness argument, or a correctness proof with no scaling data, each fails half the venue. Reviewers are parallel-systems experts who will interrogate the baseline, the machine, and the variance before they believe a number.
Match evidence to the claim
| Claim shape | Evidence PPoPP expects | Common failure it catches |
|---|---|---|
| A lock-free/wait-free structure | Throughput vs. thread count under varied contention; a linearizability/progress argument; memory-reclamation overhead | Single contention level; "no race seen" instead of an argument |
| A parallel runtime/scheduler | Overhead vs. sequential; strong+weak scaling on real workloads; load-balance behavior | Microbenchmarks only; no real application |
| A GPU/accelerator technique | Speedup over a strong GPU baseline; occupancy/divergence analysis; transfer costs counted | Ignoring host-device transfer; a weak baseline kernel |
| A parallel algorithm | Scaling on real inputs; NUMA/locality effects; comparison to the best known implementation | One input; a naive baseline |
| A memory-model / race tool | Soundness/coverage claims; runtime overhead; false-positive/negative characterization | Overhead unmeasured; no ground truth |
The scalability story
- Show the curve. Report performance as a function of thread/core count, not one configuration. The interesting information is the shape: linear region, saturation point, collapse.
- Distinguish strong vs. weak scaling and label which you show. Strong scaling (fixed problem, more cores) and weak scaling (problem grows with cores) answer different questions; conflating them is a classic PPoPP tell.
- Sweep the topology. Cross-socket and NUMA effects, thread pinning, and (for GPUs) occupancy and divergence often dominate; a single-socket-only result invites "what about NUMA?"
- Count the hidden costs. Memory reclamation, host-device transfer, allocation, and scheduling overhead belong inside the reported numbers, not in a footnote.
Correctness under concurrency
- Provide an argument, not just testing: linearizability (with linearization points), lock-freedom/wait-freedom (progress), or a checked property. "Passed a stress test" bounds confidence but does not establish correctness.
- Name the memory model you assume (C/C++11 atomics, the GPU model, hardware TSO) and show your synchronization is correct under it, not just under sequential consistency.
- If you use a model checker or race detector to support the claim, report its configuration and what it covers.
Baselines that survive scrutiny
- Compare to the strongest real competitor, at the competitor's best settings, on the same machine — not to your own unoptimized code and not to a strawman.
- Rebuild and re-tune baselines yourself where feasible; citing a competitor's paper number measured on different hardware is not a fair comparison.
- If you are the first at something, construct the most credible reasonable baseline and justify it.
Measurement hygiene
[Repeats] multiple runs; report median/mean with variance (error bars / percentiles)
[Warm-up] discard JIT/cache/allocator warm-up; state the steady-state protocol
[Pinning] pin threads to cores; state the topology and the pinning policy
[Isolation] quiescent machine; no co-tenants; disable turbo/frequency scaling or report it
[Inputs] real workloads plus targeted microbenchmarks; state sizes and sources
[Provenance] exact CPU/GPU, socket/NUMA layout, memory, compiler and flags, OS
A single-run bar chart with no error bars, on an unstated machine, is the evaluation a PPoPP reviewer trusts least.
Anticipate the rebuttal questions at design time
The two questions PPoPP reviewers ask most — "does it still scale at higher core counts / on
another GPU?" and "how does it compare to baseline X?" — cannot be answered in the short
rebuttal window if the runs were never made. Pre-run the larger core sweep and the obvious
alternative baseline before submission so the numbers are already in hand (see
ppopp-author-response).
Output format
[Twin bar] correctness argument present? scalability curve present? both required
[Scaling] strong/weak labeled, core sweep, NUMA/GPU topology, hidden costs counted? yes/no
[Correctness] hazard + argument (linearizability/progress) under a named memory model? yes/no
[Baselines] strongest real competitor, same machine, tuned? yes/no
[Hygiene] repeats+variance, warm-up, pinning, isolation, provenance? list gaps
[Rebuttal pre-runs] higher core count + alternative baseline already measured? yes/no
Version History
- 9f86f09 Current 2026-07-19 17:17


