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// SPDX-License-Identifier: BSD-3-Clause
/*
* vecadd_loop.cu - 100 repeated vectorAdd launches, soak-style.
*
* The same three device buffers are reused for 100 identical vadd launches:
* the point is repetition and stability, not new data. Every 10th launch the
* result is copied back and verified element by element against the
* host-computed a+b, so a silent corruption that only appears after many
* launches is caught.
*
* Output lines are stable and greppable:
*
* DEVICE <name> cc=<major>.<minor> sm=<count> mem=<bytes>
* VERIFY launch=<n> bad=<mismatches>
* LOOP launches=100 bad=<mismatches>
* STATUS OK|FAIL
*
* Build with a static CUDA runtime (--cudart=static) so the guest only needs
* the driver's libcuda.so, not a CUDA toolkit installation:
*
* nvcc -O2 --cudart=static -o vecadd_loop vecadd_loop.cu
*
* Then, from the guest: /tmp/vecadd_loop
*/
#include <cstdio>
#include <cstdlib>
#include <cstdint>
#include <cuda_runtime.h>
#define NLAUNCH 100
#define VERIFY_EVERY 10
#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];
}
int main(void)
{
cudaDeviceProp prop;
const int n = 1 << 15;
size_t bytes = (size_t)n * sizeof(float);
float *h_a, *h_b, *h_c;
float *d_a, *d_b, *d_c;
int bad = 0, i, launch;
setvbuf(stdout, NULL, _IONBF, 0);
CHECK(cudaGetDeviceProperties(&prop, 0));
printf("DEVICE %s cc=%d.%d sm=%d mem=%llu\n", prop.name,
prop.major, prop.minor, prop.multiProcessorCount,
(unsigned long long)prop.totalGlobalMem);
h_a = (float *)malloc(bytes);
h_b = (float *)malloc(bytes);
h_c = (float *)malloc(bytes);
if (!h_a || !h_b || !h_c)
return 1;
for (i = 0; i < n; i++) {
h_a[i] = (float)(i % 1000) * 0.5f;
h_b[i] = (float)(i % 997) * 0.25f;
}
CHECK(cudaMalloc(&d_a, bytes));
CHECK(cudaMalloc(&d_b, bytes));
CHECK(cudaMalloc(&d_c, bytes));
CHECK(cudaMemcpy(d_a, h_a, bytes, cudaMemcpyHostToDevice));
CHECK(cudaMemcpy(d_b, h_b, bytes, cudaMemcpyHostToDevice));
for (launch = 1; launch <= NLAUNCH; launch++) {
vadd<<<(n + 255) / 256, 256>>>(d_a, d_b, d_c, n);
CHECK(cudaGetLastError());
if (launch % VERIFY_EVERY != 0)
continue;
CHECK(cudaDeviceSynchronize());
CHECK(cudaMemcpy(h_c, d_c, bytes, cudaMemcpyDeviceToHost));
{
int vbad = 0;
for (i = 0; i < n; i++) {
if (h_c[i] != h_a[i] + h_b[i])
vbad++;
}
printf("VERIFY launch=%d bad=%d\n", launch, vbad);
bad += vbad;
}
}
CHECK(cudaDeviceSynchronize());
printf("LOOP launches=%d bad=%d\n", NLAUNCH, bad);
if (bad != 0) {
printf("STATUS FAIL\n");
return 1;
}
printf("STATUS OK\n");
CHECK(cudaFree(d_a));
CHECK(cudaFree(d_b));
CHECK(cudaFree(d_c));
free(h_a);
free(h_b);
free(h_c);
return 0;
}
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