From c8ccdd772c7650f19d14f143f34b700813575746 Mon Sep 17 00:00:00 2001 From: Arthur Hanson Rasmusson Date: Thu, 8 Oct 2026 04:15:24 -0400 Subject: vgsp+guest-diag: kcore-truth pin resolver (pool/pushbuffer/channel ring+userd) + GR ring userd-derived candidates guest_pin_stream.py now resolves translations entirely from guest truth via /proc/kcore + a manual page-table walk (no QMP races): the CE semaphore pool and pushbuffer memory from the UVM rm_mem structures, and each channel's GPFIFO ring + GPPUT from the tracking semaphore's embedding uvm_channel_t (channel_info located by its gpFifoGpuVa value). This removes the watcher pipeline's flakiness on the cudaMalloc stall class (missing pool/pushbuffer pins). gsp_sema_service.c: svc_gr_ring_autopin tries the guest-registered USERD memdesc base as a ring candidate (the fixed FB convention only matches when the guest's VRAM allocator happens to reproduce the old layout), plus an optional (gsp_sema_dbg) one-shot FB scan + raw-word diagnostics when every candidate fails. tools/cuda-ab/p2: self-checking arbitrary-kernel acceptance suite (10 programs: sequential launches, shapes, params, smem/GEMM, streams, malloc churn, printf+error, FMA benchmark, mixed, managed probe) with host oracle expectations and a guest runner. --- tools/cuda-ab/p2/src/p2_bench.cu | 95 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 tools/cuda-ab/p2/src/p2_bench.cu (limited to 'tools/cuda-ab/p2/src/p2_bench.cu') diff --git a/tools/cuda-ab/p2/src/p2_bench.cu b/tools/cuda-ab/p2/src/p2_bench.cu new file mode 100644 index 0000000..2d1db09 --- /dev/null +++ b/tools/cuda-ab/p2/src/p2_bench.cu @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: BSD-3-Clause +/* + * p2_bench - compute-heavy FMA benchmark with a fixed, verifiable result. + * + * 8192 threads each run a 250,000-iteration serial chain of correctly + * rounded FMAs (__fmaf_rn on device, fmaf on host), producing 2.05e9 FMAs. + * Both implementations are IEEE-correctly-rounded, so the per-thread final + * value must match the host exactly (bad=0); the same value is printed for + * the A/B comparison. A TIMING line (ignored by the harness comparison) + * reports wall-clock ms and GFLOP/s for the performance demonstration. + * Device memory: 32 KB output (8 pages). + */ +#include "common.h" +#include + +#define BENCH_THREADS 8192 +#define BENCH_ITERS 250000 +#define BENCH_A 0.9999f +#define BENCH_B 1.0e-6f + +__global__ void fma_chain(float *out, int iters, int n) +{ + int i = blockIdx.x * blockDim.x + threadIdx.x; + float x = 0.0f; + + if (i >= n) + return; + for (int t = 0; t < iters; t++) + x = __fmaf_rn(x, BENCH_A, BENCH_B); + out[i] = x; +} + +static float host_chain(int iters) +{ + float x = 0.0f; + + for (int t = 0; t < iters; t++) + x = fmaf(x, BENCH_A, BENCH_B); + return x; +} + +int main(int argc, char **argv) +{ + float ref = host_chain(BENCH_ITERS); + + if (p2_emit_mode(argc, argv)) { + printf("RESULT bench threads=%d iters=%d bad=0 value=%.9g\n", + BENCH_THREADS, BENCH_ITERS, (double)ref); + printf("TIMING bench ms=0.000 gflops=0.00 (emit mode: no GPU)\n"); + return p2_status(0); + } + + p2_device_info(); + + float *d_out = NULL, *got = (float *)malloc(sizeof(float) * BENCH_THREADS); + + if (!got) + return 1; + P2_CHECK(cudaMalloc(&d_out, sizeof(float) * BENCH_THREADS)); + + cudaEvent_t t0, t1; + float ms = 0.0f; + + P2_CHECK(cudaEventCreate(&t0)); + P2_CHECK(cudaEventCreate(&t1)); + P2_CHECK(cudaEventRecord(t0)); + fma_chain<<>>(d_out, BENCH_ITERS, + BENCH_THREADS); + P2_CHECK(cudaGetLastError()); + P2_CHECK(cudaEventRecord(t1)); + P2_CHECK(cudaDeviceSynchronize()); + P2_CHECK(cudaEventElapsedTime(&ms, t0, t1)); + P2_CHECK(cudaMemcpy(got, d_out, sizeof(float) * BENCH_THREADS, + cudaMemcpyDeviceToHost)); + + int bad = 0; + + for (int i = 0; i < BENCH_THREADS; i++) + if (got[i] != ref) + bad++; + printf("RESULT bench threads=%d iters=%d bad=%d value=%.9g\n", + BENCH_THREADS, BENCH_ITERS, bad, (double)got[0]); + if (ms > 0.0f) { + double flops = 2.0 * (double)BENCH_THREADS * (double)BENCH_ITERS; + + printf("TIMING bench ms=%.3f gflops=%.2f\n", (double)ms, + flops / ((double)ms * 1.0e6)); + } + + cudaEventDestroy(t0); + cudaEventDestroy(t1); + cudaFree(d_out); + free(got); + return p2_status(bad); +} -- cgit v1.2.3