3760cede0f
- Use context in all tests. - Use context in R. - Use context in C API DMatrix initialization. (0 threads is used as dft).
59 lines
1.6 KiB
C++
59 lines
1.6 KiB
C++
/**
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* Copyright 2022-2023 by XGBoost Contributors
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*/
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#include "threading_utils.h"
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#include <fstream>
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#include <string>
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#include "xgboost/logging.h"
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namespace xgboost {
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namespace common {
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int32_t GetCfsCPUCount() noexcept {
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#if defined(__linux__)
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// https://bugs.openjdk.java.net/browse/JDK-8146115
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// http://hg.openjdk.java.net/jdk/hs/rev/7f22774a5f42
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// RAM limit /sys/fs/cgroup/memory.limit_in_bytes
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// swap limt /sys/fs/cgroup/memory.memsw.limit_in_bytes
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auto read_int = [](char const* const file_path) noexcept {
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std::ifstream fin(file_path);
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if (!fin) {
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return -1;
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}
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std::string value;
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fin >> value;
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try {
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return std::stoi(value);
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} catch (std::exception const&) {
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return -1;
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}
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};
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// complete fair scheduler from Linux
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auto const cfs_quota(read_int("/sys/fs/cgroup/cpu/cpu.cfs_quota_us"));
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auto const cfs_period(read_int("/sys/fs/cgroup/cpu/cpu.cfs_period_us"));
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if ((cfs_quota > 0) && (cfs_period > 0)) {
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return std::max(cfs_quota / cfs_period, 1);
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}
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#endif // defined(__linux__)
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return -1;
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}
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std::int32_t OmpGetNumThreads(std::int32_t n_threads) {
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// Don't use parallel if we are in a parallel region.
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if (omp_in_parallel()) {
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return 1;
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}
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// If -1 or 0 is specified by the user, we default to maximum number of threads.
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if (n_threads <= 0) {
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n_threads = std::min(omp_get_num_procs(), omp_get_max_threads());
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}
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// Honor the openmp thread limit, which can be set via environment variable.
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n_threads = std::min(n_threads, OmpGetThreadLimit());
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n_threads = std::max(n_threads, 1);
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return n_threads;
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}
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} // namespace common
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} // namespace xgboost
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