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guess-rev.sh
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dbrownell authored
- The guess-rev.sh script is now a tweaked version of "setlocalversion" as seen in Linux, U-Boot, and various other projects. When it finds source control support (git, hg, svn) it uses IDs from there. Else (specific to this project) it reports itself as "-snapshot", e.g. from gitweb. I verified this new "guess-rev.sh" script runs under Cygwin. - Also update the generic version strings to be like "0.3.0-dev" (during development) instead of the very long "0.3.0-in-development". These also show up in the PDF docs. For better tracking, we might eventually change these strings to include the version IDs too. - Change the startup banner version strings so they include the guess-rev output. Development and release versions with GIT will be like Open On-Chip Debugger 0.3.0-dev-00282-g7191a4f-dirty (2009-10-05-20:57) Open On-Chip Debugger 0.3.0 (2009-10-05-20:57) instead of the previous SVN-specific (even when using git-svn!) Open On-Chip Debugger 0.3.0-in-development (2009-10-05-01:39) svn:exported Open On-Chip Debugger 0.3.0 (2009-10-05-01:39) Release git-svn-id: svn://svn.berlios.de/openocd/trunk@2809 b42882b7-edfa-0310-969c-e2dbd0fdcd60
dbrownell authored- The guess-rev.sh script is now a tweaked version of "setlocalversion" as seen in Linux, U-Boot, and various other projects. When it finds source control support (git, hg, svn) it uses IDs from there. Else (specific to this project) it reports itself as "-snapshot", e.g. from gitweb. I verified this new "guess-rev.sh" script runs under Cygwin. - Also update the generic version strings to be like "0.3.0-dev" (during development) instead of the very long "0.3.0-in-development". These also show up in the PDF docs. For better tracking, we might eventually change these strings to include the version IDs too. - Change the startup banner version strings so they include the guess-rev output. Development and release versions with GIT will be like Open On-Chip Debugger 0.3.0-dev-00282-g7191a4f-dirty (2009-10-05-20:57) Open On-Chip Debugger 0.3.0 (2009-10-05-20:57) instead of the previous SVN-specific (even when using git-svn!) Open On-Chip Debugger 0.3.0-in-development (2009-10-05-01:39) svn:exported Open On-Chip Debugger 0.3.0 (2009-10-05-01:39) Release git-svn-id: svn://svn.berlios.de/openocd/trunk@2809 b42882b7-edfa-0310-969c-e2dbd0fdcd60
cudapit.cu 2.08 KiB
//
// cudapit.cu
// Neil Gershenfeld 3/1/20
// calculation of pi by a CUDA multi-GPU thread sum
// pi = 3.14159265358979323846
//
#include <iostream>
#include <chrono>
#include <thread>
#include <vector>
#include <cstdint>
uint64_t blocks = 1024;
uint64_t threads = 1024;
uint64_t nloop = 10000000;
uint64_t npts = blocks*threads;
std::vector<double> results;
__global__ void init(double *arr,uint64_t nloop,uint64_t npts,int index) {
uint64_t i = blockIdx.x*blockDim.x+threadIdx.x;
uint64_t start = nloop*i+npts*nloop*index+1;
uint64_t end = nloop*(i+1)+npts*nloop*index+1;
arr[i] = 0;
for (uint64_t j = start; j < end; ++j)
arr[i] += 0.5/((j-0.75)*(j-0.25));
}
__global__ void reduce_sum(double *arr,uint64_t len) {
uint64_t i = blockIdx.x*blockDim.x+threadIdx.x;
if (i < len)
arr[i] += arr[i+len];
}
void reduce(double *arr) {
uint64_t len = npts >> 1;
while (1) {
reduce_sum<<<blocks,threads>>>(arr,len);
len = len >> 1;
if (len == 0)
return;
}
}
void sum(int index) {
cudaSetDevice(index);
double harr[1],*darr;
cudaMalloc(&darr,npts*sizeof(double));
init<<<blocks,threads>>>(darr,nloop,npts,index);
reduce(darr);
cudaDeviceSynchronize();
cudaMemcpy(harr,darr,8,cudaMemcpyDeviceToHost);
results[index] = harr[0];
cudaFree(darr);
}
int main(void) {
int ngpus;
cudaGetDeviceCount(&ngpus);
std::thread threads[ngpus];
double pi = 0;
auto tstart = std::chrono::high_resolution_clock::now();
for (int i = 0; i < ngpus; ++i) {
results.push_back(0);
threads[i] = std::thread(sum,i);
}
for (int i = 0; i < ngpus; ++i) {
threads[i].join();
pi += results[i];
}
auto tend = std::chrono::high_resolution_clock::now();
auto dt = std::chrono::duration_cast<std::chrono::microseconds>(tend-tstart).count();
auto gflops = npts*nloop*ngpus*5.0/dt/1e3;
std::cout << "npts: " << npts << " nloop: " << nloop << " ngpus: " << ngpus << " pi: " << pi << '\n';
std::cout << "time: " << 1e-6*dt << " estimated GFlops: " << gflops << '\n';
return 0;
}