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// SPDX-License-Identifier: BSD-3-Clause
/*
* streams2_probe.cu - instrumented streams2 to localize the deterministic
* failure: per-array mismatch counts, first-bad indices with values, and a
* GPU-side verify-kernel digest of the device buffers (to separate "device
* pages never written" from "D2H readback wrong").
*
* Modes (argv[1]):
* A : exactly streams2's shape (control)
* B : like A but the two D2H copy-backs use synchronous cudaMemcpy
* C : like A but no events cross the streams; both streams are joined
* with cudaStreamSynchronize before any copy-back
* D : single stream (everything on s1)
*
* Build: nvcc -O2 --cudart=static -o streams2_probe streams2_probe.cu
*/
#include <cstdio>
#include <cstdlib>
#include <cstdint>
#include <cstring>
#include <cuda_runtime.h>
#define CHECK(x) \
do { \
cudaError_t e_ = (x); \
if (e_ != cudaSuccess) { \
printf("CUDA_ERROR %s at line %d\n", \
cudaGetErrorString(e_), __LINE__); \
printf("STATUS FAIL\n"); \
return 1; \
} \
} while (0)
__global__ void vadd(const float *a, const float *b, float *c, int n)
{
int i = blockIdx.x * blockDim.x + threadIdx.x;
if (i < n)
c[i] = a[i] + b[i];
}
__global__ void scale(float *c, float s, int n)
{
int i = blockIdx.x * blockDim.x + threadIdx.x;
if (i < n)
c[i] = c[i] * s;
}
/* GPU-side digest: counts of matches for c1==a1+b1 and c2==(a2+b2)*2 */
__global__ void digest(const float *a1, const float *b1, const float *c1,
const float *a2, const float *b2, const float *c2,
int n, unsigned long long *out)
{
int i = blockIdx.x * blockDim.x + threadIdx.x;
if (i >= n)
return;
if (c1[i] == a1[i] + b1[i])
atomicAdd(&out[0], 1ull);
if (c2[i] == (a2[i] + b2[i]) * 2.0f)
atomicAdd(&out[1], 1ull);
}
static int report(const char *tag, const float *h_c, const float *h_a,
const float *h_b, const float *h_a2, const float *h_b2,
int n, float scale2)
{
int bad = 0, i, shown = 0;
for (i = 0; i < n; i++) {
float want = h_a[i] + h_b[i];
if (scale2 != 1.0f)
want = (h_a2[i] + h_b2[i]) * scale2;
if (h_c[i] != want) {
bad++;
if (shown < 4) {
printf("FIRSTBAD %s i=%d got=%g want=%g\n",
tag, i, h_c[i], want);
shown++;
}
}
}
printf("BAD %s n=%d bad=%d\n", tag, n, bad);
return bad;
}
int main(int argc, char **argv)
{
const char *mode = argc > 1 ? argv[1] : "A";
cudaDeviceProp prop;
const int n = 1 << 15;
const float s2 = 2.0f;
size_t bytes = (size_t)n * sizeof(float);
float *h_a1, *h_b1, *h_c1, *h_a2, *h_b2, *h_c2;
float *d_a1, *d_b1, *d_c1, *d_a2, *d_b2, *d_c2;
unsigned long long *d_out, h_out[2];
cudaStream_t s1, s2s;
cudaEvent_t ev_add1, ev_scale2, t0, t1;
float ms = 0.0f;
int i;
const int grid = (n + 255) / 256;
setvbuf(stdout, NULL, _IONBF, 0);
CHECK(cudaGetDeviceProperties(&prop, 0));
printf("DEVICE %s mode=%s\n", prop.name, mode);
h_a1 = (float *)malloc(bytes);
h_b1 = (float *)malloc(bytes);
h_c1 = (float *)malloc(bytes);
h_a2 = (float *)malloc(bytes);
h_b2 = (float *)malloc(bytes);
h_c2 = (float *)malloc(bytes);
for (i = 0; i < n; i++) {
h_a1[i] = (float)(i % 1000) * 0.5f;
h_b1[i] = (float)(i % 997) * 0.25f;
h_a2[i] = (float)(i % 991) * 0.125f;
h_b2[i] = (float)(i % 983) * 0.0625f;
}
memset(h_c1, 0xCD, bytes);
memset(h_c2, 0xCD, bytes);
CHECK(cudaMalloc(&d_a1, bytes));
CHECK(cudaMalloc(&d_b1, bytes));
CHECK(cudaMalloc(&d_c1, bytes));
CHECK(cudaMalloc(&d_a2, bytes));
CHECK(cudaMalloc(&d_b2, bytes));
CHECK(cudaMalloc(&d_c2, bytes));
CHECK(cudaMalloc(&d_out, 2 * sizeof(unsigned long long)));
printf("DPTRS da1=%p db1=%p dc1=%p da2=%p db2=%p dc2=%p\n",
(void *)d_a1, (void *)d_b1, (void *)d_c1, (void *)d_a2,
(void *)d_b2, (void *)d_c2);
CHECK(cudaStreamCreate(&s1));
CHECK(cudaStreamCreate(&s2s));
CHECK(cudaEventCreate(&ev_add1));
CHECK(cudaEventCreate(&ev_scale2));
CHECK(cudaEventCreate(&t0));
CHECK(cudaEventCreate(&t1));
CHECK(cudaEventRecord(t0));
if (!strcmp(mode, "D")) {
CHECK(cudaMemcpyAsync(d_a1, h_a1, bytes,
cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_b1, h_b1, bytes,
cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_a2, h_a2, bytes,
cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_b2, h_b2, bytes,
cudaMemcpyHostToDevice, s1));
vadd<<<grid, 256, 0, s1>>>(d_a1, d_b1, d_c1, n);
vadd<<<grid, 256, 0, s1>>>(d_a2, d_b2, d_c2, n);
CHECK(cudaStreamSynchronize(s1));
scale<<<grid, 256, 0, s1>>>(d_c2, s2, n);
CHECK(cudaStreamSynchronize(s1));
CHECK(cudaMemcpy(h_c1, d_c1, bytes, cudaMemcpyDeviceToHost));
CHECK(cudaMemcpy(h_c2, d_c2, bytes, cudaMemcpyDeviceToHost));
goto verify;
}
if (!strcmp(mode, "S")) {
/* staged verification: check device content after every step */
float *hb1 = (float *)malloc(bytes);
float *hb2 = (float *)malloc(bytes);
float *hb3 = (float *)malloc(bytes);
CHECK(cudaMemcpy(d_a1, h_a1, bytes, cudaMemcpyHostToDevice));
CHECK(cudaMemcpy(d_b1, h_b1, bytes, cudaMemcpyHostToDevice));
CHECK(cudaMemcpy(d_a2, h_a2, bytes, cudaMemcpyHostToDevice));
CHECK(cudaMemcpy(d_b2, h_b2, bytes, cudaMemcpyHostToDevice));
CHECK(cudaMemcpy(hb1, d_a1, bytes, cudaMemcpyDeviceToHost));
{ int b = 0; for (i = 0; i < n; i++) if (hb1[i] != h_a1[i]) b++;
printf("STAGE-IN da1 bad=%d\n", b); }
CHECK(cudaMemcpy(hb1, d_b1, bytes, cudaMemcpyDeviceToHost));
{ int b = 0; for (i = 0; i < n; i++) if (hb1[i] != h_b1[i]) b++;
printf("STAGE-IN db1 bad=%d\n", b); }
CHECK(cudaMemcpy(hb1, d_a2, bytes, cudaMemcpyDeviceToHost));
{ int b = 0; for (i = 0; i < n; i++) if (hb1[i] != h_a2[i]) b++;
printf("STAGE-IN da2 bad=%d\n", b); }
CHECK(cudaMemcpy(hb1, d_b2, bytes, cudaMemcpyDeviceToHost));
{ int b = 0; for (i = 0; i < n; i++) if (hb1[i] != h_b2[i]) b++;
printf("STAGE-IN db2 bad=%d\n", b); }
vadd<<<grid, 256, 0, s1>>>(d_a1, d_b1, d_c1, n);
CHECK(cudaDeviceSynchronize());
CHECK(cudaMemcpy(hb1, d_c1, bytes, cudaMemcpyDeviceToHost));
{ int b = 0, first = -1; for (i = 0; i < n; i++)
if (hb1[i] != h_a1[i] + h_b1[i]) { b++;
if (first < 0) { first = i;
printf("S1-FIRSTBAD i=%d got=%g want=%g a2b2=%g\n",
i, hb1[i], h_a1[i]+h_b1[i], h_a2[i]+h_b2[i]); } }
printf("STAGE vadd1->c1 readback bad=%d first=%d\n", b, first); }
CHECK(cudaDeviceSynchronize());
vadd<<<grid, 256, 0, s2s>>>(d_a2, d_b2, d_c2, n);
CHECK(cudaDeviceSynchronize());
CHECK(cudaMemcpy(hb2, d_c2, bytes, cudaMemcpyDeviceToHost));
{ int b = 0, first = -1; for (i = 0; i < n; i++)
if (hb2[i] != h_a2[i] + h_b2[i]) { b++; if (first < 0) first = i; }
printf("STAGE vadd2->c2 readback bad=%d first=%d\n", b, first); }
scale<<<grid, 256, 0, s2s>>>(d_c2, s2, n);
CHECK(cudaDeviceSynchronize());
CHECK(cudaMemcpy(hb3, d_c2, bytes, cudaMemcpyDeviceToHost));
{ int b = 0, first = -1; for (i = 0; i < n; i++)
if (hb3[i] != (h_a2[i] + h_b2[i]) * 2.0f) { b++; if (first < 0) first = i; }
printf("STAGE scale->c2 readback bad=%d first=%d\n", b, first); }
/* second readback of c1 AFTER everything: does it change? */
CHECK(cudaMemcpy(hb1, d_c1, bytes, cudaMemcpyDeviceToHost));
{ int b = 0, first = -1; for (i = 0; i < n; i++)
if (hb1[i] != h_a1[i] + h_b1[i]) { b++; if (first < 0) first = i; }
printf("STAGE c1-late readback bad=%d first=%d\n", b, first); }
printf("STATUS OK\n");
return 0;
}
if (!strcmp(mode, "C")) {
CHECK(cudaMemcpyAsync(d_a1, h_a1, bytes,
cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_b1, h_b1, bytes,
cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_a2, h_a2, bytes,
cudaMemcpyHostToDevice, s2s));
CHECK(cudaMemcpyAsync(d_b2, h_b2, bytes,
cudaMemcpyHostToDevice, s2s));
vadd<<<grid, 256, 0, s1>>>(d_a1, d_b1, d_c1, n);
vadd<<<grid, 256, 0, s2s>>>(d_a2, d_b2, d_c2, n);
CHECK(cudaStreamSynchronize(s1));
CHECK(cudaStreamSynchronize(s2s));
scale<<<grid, 256, 0, s2s>>>(d_c2, s2, n);
CHECK(cudaStreamSynchronize(s2s));
CHECK(cudaMemcpyAsync(h_c1, d_c1, bytes,
cudaMemcpyDeviceToHost, s1));
CHECK(cudaMemcpyAsync(h_c2, d_c2, bytes,
cudaMemcpyDeviceToHost, s2s));
CHECK(cudaStreamSynchronize(s1));
CHECK(cudaStreamSynchronize(s2s));
goto verify;
}
/* A and B: original shape */
CHECK(cudaMemcpyAsync(d_a1, h_a1, bytes, cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_b1, h_b1, bytes, cudaMemcpyHostToDevice, s1));
CHECK(cudaMemcpyAsync(d_a2, h_a2, bytes, cudaMemcpyHostToDevice, s2s));
CHECK(cudaMemcpyAsync(d_b2, h_b2, bytes, cudaMemcpyHostToDevice, s2s));
vadd<<<grid, 256, 0, s1>>>(d_a1, d_b1, d_c1, n);
vadd<<<grid, 256, 0, s2s>>>(d_a2, d_b2, d_c2, n);
CHECK(cudaGetLastError());
CHECK(cudaEventRecord(ev_add1, s1));
CHECK(cudaStreamWaitEvent(s2s, ev_add1, 0));
scale<<<grid, 256, 0, s2s>>>(d_c2, s2, n);
CHECK(cudaGetLastError());
CHECK(cudaEventRecord(ev_scale2, s2s));
CHECK(cudaStreamWaitEvent(s1, ev_scale2, 0));
if (!strcmp(mode, "B")) {
CHECK(cudaStreamSynchronize(s2s));
CHECK(cudaMemcpy(h_c1, d_c1, bytes, cudaMemcpyDeviceToHost));
CHECK(cudaMemcpy(h_c2, d_c2, bytes, cudaMemcpyDeviceToHost));
} else {
CHECK(cudaMemcpyAsync(h_c1, d_c1, bytes,
cudaMemcpyDeviceToHost, s1));
CHECK(cudaMemcpyAsync(h_c2, d_c2, bytes,
cudaMemcpyDeviceToHost, s2s));
}
CHECK(cudaEventRecord(t1, s1));
CHECK(cudaStreamSynchronize(s1));
CHECK(cudaStreamSynchronize(s2s));
CHECK(cudaEventElapsedTime(&ms, t0, t1));
verify:
{
int bad1, bad2;
bad1 = report("C1", h_c1, h_a1, h_b1, h_a2, h_b2, n, 1.0f);
bad2 = report("C2", h_c2, h_a2, h_b2, h_a2, h_b2, n, s2);
printf("STREAMS n=%d bad=%d\n", n, bad1 + bad2);
printf("TIMING ms=%.3f\n", ms);
/* GPU-side digest of the device buffers */
CHECK(cudaMemset(d_out, 0, 2 * sizeof(unsigned long long)));
digest<<<grid, 256>>>(d_a1, d_b1, d_c1, d_a2, d_b2, d_c2, n,
d_out);
CHECK(cudaDeviceSynchronize());
CHECK(cudaMemcpy(h_out, d_out, 2 * sizeof(unsigned long long),
cudaMemcpyDeviceToHost));
printf("GPU-DIGEST c1_ok=%llu c2_ok=%llu\n", h_out[0],
h_out[1]);
printf("STATUS %s\n", (bad1 | bad2) ? "FAIL" : "OK");
}
return 0;
}
|
