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CompareFlat.cu
/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the CC-by-NC license found in the
* LICENSE file in the root directory of this source tree.
*/
// Copyright 2004-present Facebook. All Rights Reserved.
#include "../../IndexFlat.h"
#include "../../utils.h"
#include "../GpuIndexFlat.h"
#include "IndexWrapper.h"
#include "../test/TestUtils.h"
#include "../utils/DeviceTensor.cuh"
#include "../utils/DeviceUtils.h"
#include "../utils/HostTensor.cuh"
#include "../utils/Timer.h"
#include <gflags/gflags.h>
#include <map>
#include <memory>
#include <vector>
#include <cuda_profiler_api.h>
DEFINE_int32(k, 3, "final number of closest results returned");
DEFINE_int32(num, 128, "# of vecs");
DEFINE_int32(dim, 128, "# of dimensions");
DEFINE_int32(num_queries, 3, "number of query vectors");
DEFINE_bool(diff, true, "show exact distance + index output discrepancies");
DEFINE_bool(use_float16, false, "use encodings in float16 instead of float32");
DEFINE_bool(transposed, false, "store vectors transposed");
DEFINE_int64(seed, -1, "specify random seed");
DEFINE_int32(num_gpus, 1, "number of gpus to use");
DEFINE_int64(pinned_mem, 0, "pinned memory allocation to use");
using namespace faiss::gpu;
int main(int argc, char** argv) {
gflags::ParseCommandLineFlags(&argc, &argv, true);
cudaProfilerStop();
auto seed = FLAGS_seed != -1L ? FLAGS_seed : time(nullptr);
printf("using seed %ld\n", seed);
auto numQueries = FLAGS_num_queries;
auto index = std::unique_ptr<faiss::IndexFlatL2>(
new faiss::IndexFlatL2(FLAGS_dim));
HostTensor<float, 2, true> vecs({FLAGS_num, FLAGS_dim});
faiss::float_rand(vecs.data(), vecs.numElements(), seed);
index->add(FLAGS_num, vecs.data());
printf("Database: dim %d num vecs %d\n", FLAGS_dim, FLAGS_num);
printf("L2 lookup: %d queries, total k %d\n",
numQueries, FLAGS_k);
printf("float16 encoding %s\n", FLAGS_use_float16 ? "enabled" : "disabled");
printf("transposed storage %s\n", FLAGS_transposed ? "enabled" : "disabled");
// Convert to GPU index
printf("Copying index to %d GPU(s)...\n", FLAGS_num_gpus);
auto initFn = [&index](faiss::gpu::GpuResources* res, int dev) ->
std::unique_ptr<faiss::gpu::GpuIndexFlatL2> {
((faiss::gpu::StandardGpuResources*) res)->setPinnedMemory(
FLAGS_pinned_mem);
GpuIndexFlatConfig config;
config.device = dev;
config.useFloat16 = FLAGS_use_float16;
config.storeTransposed = FLAGS_transposed;
auto p = std::unique_ptr<faiss::gpu::GpuIndexFlatL2>(
new faiss::gpu::GpuIndexFlatL2(res, index.get(), config));
return p;
};
IndexWrapper<faiss::gpu::GpuIndexFlatL2> gpuIndex(FLAGS_num_gpus, initFn);
printf("copy done\n");
// Build query vectors
HostTensor<float, 2, true> cpuQuery({numQueries, FLAGS_dim});
faiss::float_rand(cpuQuery.data(), cpuQuery.numElements(), seed);
// Time faiss CPU
HostTensor<float, 2, true> cpuDistances({numQueries, FLAGS_k});
HostTensor<faiss::Index::idx_t, 2, true> cpuIndices({numQueries, FLAGS_k});
float cpuTime = 0.0f;
{
CpuTimer timer;
index->search(numQueries,
cpuQuery.data(),
FLAGS_k,
cpuDistances.data(),
cpuIndices.data());
cpuTime = timer.elapsedMilliseconds();
}
printf("CPU time %.3f ms\n", cpuTime);
HostTensor<float, 2, true> gpuDistances({numQueries, FLAGS_k});
HostTensor<faiss::Index::idx_t, 2, true> gpuIndices({numQueries, FLAGS_k});
CUDA_VERIFY(cudaProfilerStart());
faiss::gpu::synchronizeAllDevices();
float gpuTime = 0.0f;
// Time GPU
{
CpuTimer timer;
gpuIndex.getIndex()->search(cpuQuery.getSize(0),
cpuQuery.data(),
FLAGS_k,
gpuDistances.data(),
gpuIndices.data());
// There is a device -> host copy above, so no need to time
// additional synchronization with the GPU
gpuTime = timer.elapsedMilliseconds();
}
CUDA_VERIFY(cudaProfilerStop());
printf("GPU time %.3f ms\n", gpuTime);
compareLists(cpuDistances.data(), cpuIndices.data(),
gpuDistances.data(), gpuIndices.data(),
numQueries, FLAGS_k,
"", true, FLAGS_diff, false);
CUDA_VERIFY(cudaDeviceSynchronize());
// printf("\ncudaMalloc usage %zd\n",
// resources.getMemoryManager().getHighWaterCudaMalloc());
return 0;
}
faiss::gpu::CpuTimer::elapsedMilliseconds
float elapsedMilliseconds()
Returns elapsed time in milliseconds.
Definition: Timer.cpp:52
faiss::gpu::GpuIndexFlatConfig::storeTransposed
bool storeTransposed
Definition: GpuIndexFlat.h:48
faiss::IndexFlatL2
Definition: IndexFlat.h:79
faiss::gpu::GpuResources
Definition: GpuResources.h:23
faiss::gpu::CpuTimer
CPU wallclock elapsed timer.
Definition: Timer.h:42
faiss::gpu::GpuIndexFlatConfig::useFloat16
bool useFloat16
Whether or not data is stored as float16.
Definition: GpuIndexFlat.h:35
faiss::gpu::GpuIndexConfig::device
int device
GPU device on which the index is resident.
Definition: GpuIndex.h:27
faiss::gpu::GpuIndexFlatConfig
Definition: GpuIndexFlat.h:27
faiss::gpu::StandardGpuResources
Definition: StandardGpuResources.h:23
faiss::gpu::GpuIndexFlatL2
Definition: GpuIndexFlat.h:169
faiss::gpu::HostTensor
Definition: HostTensor.cuh:22
faiss::gpu::IndexWrapper
Definition: IndexWrapper.h:25