2 * This file is part of the GROMACS molecular simulation package.
4 * Copyright (c) 2012,2013,2014,2015,2016 by the GROMACS development team.
5 * Copyright (c) 2017,2018,2019,2020, by the GROMACS development team, led by
6 * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
7 * and including many others, as listed in the AUTHORS file in the
8 * top-level source directory and at http://www.gromacs.org.
10 * GROMACS is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public License
12 * as published by the Free Software Foundation; either version 2.1
13 * of the License, or (at your option) any later version.
15 * GROMACS is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with GROMACS; if not, see
22 * http://www.gnu.org/licenses, or write to the Free Software Foundation,
23 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 * If you want to redistribute modifications to GROMACS, please
26 * consider that scientific software is very special. Version
27 * control is crucial - bugs must be traceable. We will be happy to
28 * consider code for inclusion in the official distribution, but
29 * derived work must not be called official GROMACS. Details are found
30 * in the README & COPYING files - if they are missing, get the
31 * official version at http://www.gromacs.org.
33 * To help us fund GROMACS development, we humbly ask that you cite
34 * the research papers on the package. Check out http://www.gromacs.org.
38 #include "detecthardware.h"
50 #include "gromacs/compat/pointers.h"
51 #include "gromacs/gpu_utils/gpu_utils.h"
52 #include "gromacs/hardware/cpuinfo.h"
53 #include "gromacs/hardware/hardwaretopology.h"
54 #include "gromacs/hardware/hw_info.h"
55 #include "gromacs/simd/support.h"
56 #include "gromacs/utility/basedefinitions.h"
57 #include "gromacs/utility/basenetwork.h"
58 #include "gromacs/utility/baseversion.h"
59 #include "gromacs/utility/cstringutil.h"
60 #include "gromacs/utility/exceptions.h"
61 #include "gromacs/utility/fatalerror.h"
62 #include "gromacs/utility/gmxassert.h"
63 #include "gromacs/utility/logger.h"
64 #include "gromacs/utility/mutex.h"
65 #include "gromacs/utility/physicalnodecommunicator.h"
67 #include "architecture.h"
70 # include <unistd.h> // sysconf()
73 gmx_hw_info_t::gmx_hw_info_t(std::unique_ptr<gmx::CpuInfo> cpuInfo,
74 std::unique_ptr<gmx::HardwareTopology> hardwareTopology) :
75 cpuInfo(std::move(cpuInfo)),
76 hardwareTopology(std::move(hardwareTopology))
80 gmx_hw_info_t::~gmx_hw_info_t()
82 free_gpu_info(&gpu_info);
88 //! Convenience macro to help us avoid ifdefs each time we use sysconf
89 #if !defined(_SC_NPROCESSORS_ONLN) && defined(_SC_NPROC_ONLN)
90 # define _SC_NPROCESSORS_ONLN _SC_NPROC_ONLN
93 //! Convenience macro to help us avoid ifdefs each time we use sysconf
94 #if !defined(_SC_NPROCESSORS_CONF) && defined(_SC_NPROC_CONF)
95 # define _SC_NPROCESSORS_CONF _SC_NPROC_CONF
98 /*! \brief Information about the hardware of all nodes (common to all threads in this process).
100 * This information is constructed only when required, but thereafter
101 * its lifetime is that of the whole process, potentially across
102 * multiple successive simulation parts. It's wise to ensure that only
103 * one thread can create the information, but thereafter they can all
104 * read it without e.g. needing a std::shared_ptr to ensure its
105 * lifetime exceeds that of the thread. */
106 static std::unique_ptr<gmx_hw_info_t> g_hardwareInfo;
107 //! A mutex to protect the hwinfo structure
108 static Mutex g_hardwareInfoMutex;
110 //! Detect GPUs, if that makes sense to attempt.
111 static void gmx_detect_gpus(const gmx::MDLogger& mdlog,
112 const PhysicalNodeCommunicator& physicalNodeComm,
113 compat::not_null<gmx_hw_info_t*> hardwareInfo)
115 hardwareInfo->gpu_info.bDetectGPUs = canPerformGpuDetection();
117 if (!hardwareInfo->gpu_info.bDetectGPUs)
122 bool isMasterRankOfPhysicalNode = true;
124 isMasterRankOfPhysicalNode = (physicalNodeComm.rank_ == 0);
126 // We choose to run the detection only once with thread-MPI and
127 // use a mutex to enforce it.
128 GMX_UNUSED_VALUE(physicalNodeComm);
129 isMasterRankOfPhysicalNode = true;
132 /* The OpenCL support requires us to run detection on all ranks.
133 * With CUDA we don't need to, and prefer to detect on one rank
134 * and send the information to the other ranks over MPI. */
135 constexpr bool allRanksMustDetectGpus = (GMX_GPU_OPENCL != 0);
136 bool gpusCanBeDetected = false;
137 if (isMasterRankOfPhysicalNode || allRanksMustDetectGpus)
139 std::string errorMessage;
140 gpusCanBeDetected = isGpuDetectionFunctional(&errorMessage);
141 if (!gpusCanBeDetected)
145 .appendTextFormatted(
146 "NOTE: Detection of GPUs failed. The API reported:\n"
148 " GROMACS cannot run tasks on a GPU.",
149 errorMessage.c_str());
153 if (gpusCanBeDetected)
155 findGpus(&hardwareInfo->gpu_info);
156 // No need to tell the user anything at this point, they get a
157 // hardware report later.
161 if (!allRanksMustDetectGpus)
163 /* Broadcast the GPU info to the other ranks within this node */
164 MPI_Bcast(&hardwareInfo->gpu_info.n_dev, 1, MPI_INT, 0, physicalNodeComm.comm_);
166 if (hardwareInfo->gpu_info.n_dev > 0)
170 dev_size = hardwareInfo->gpu_info.n_dev * sizeof_gpu_dev_info();
172 if (!isMasterRankOfPhysicalNode)
174 hardwareInfo->gpu_info.deviceInfo = (struct DeviceInformation*)malloc(dev_size);
176 MPI_Bcast(hardwareInfo->gpu_info.deviceInfo, dev_size, MPI_BYTE, 0, physicalNodeComm.comm_);
177 MPI_Bcast(&hardwareInfo->gpu_info.n_dev_compatible, 1, MPI_INT, 0, physicalNodeComm.comm_);
183 //! Reduce the locally collected \p hardwareInfo over MPI ranks
184 static void gmx_collect_hardware_mpi(const gmx::CpuInfo& cpuInfo,
185 const PhysicalNodeCommunicator& physicalNodeComm,
186 compat::not_null<gmx_hw_info_t*> hardwareInfo)
188 const int ncore = hardwareInfo->hardwareTopology->numberOfCores();
189 /* Zen1 is assumed for:
190 * - family=23 with the below listed models;
193 const bool cpuIsAmdZen1 = ((cpuInfo.vendor() == CpuInfo::Vendor::Amd && cpuInfo.family() == 23
194 && (cpuInfo.model() == 1 || cpuInfo.model() == 17
195 || cpuInfo.model() == 8 || cpuInfo.model() == 24))
196 || cpuInfo.vendor() == CpuInfo::Vendor::Hygon);
198 int nhwthread, ngpu, i;
201 nhwthread = hardwareInfo->nthreads_hw_avail;
202 ngpu = hardwareInfo->gpu_info.n_dev_compatible;
203 /* Create a unique hash of the GPU type(s) in this node */
205 /* Here it might be better to only loop over the compatible GPU, but we
206 * don't have that information available and it would also require
207 * removing the device ID from the device info string.
209 for (i = 0; i < hardwareInfo->gpu_info.n_dev; i++)
213 /* Since the device ID is incorporated in the hash, the order of
214 * the GPUs affects the hash. Also two identical GPUs won't give
215 * a gpu_hash of zero after XORing.
217 get_gpu_device_info_string(stmp, hardwareInfo->gpu_info, i);
218 gpu_hash ^= gmx_string_fullhash_func(stmp, gmx_string_hash_init);
221 constexpr int numElementsCounts = 4;
222 std::array<int, numElementsCounts> countsReduced;
224 std::array<int, numElementsCounts> countsLocal = { { 0 } };
225 // Organize to sum values from only one rank within each node,
226 // so we get the sum over all nodes.
227 bool isMasterRankOfPhysicalNode = (physicalNodeComm.rank_ == 0);
228 if (isMasterRankOfPhysicalNode)
231 countsLocal[1] = ncore;
232 countsLocal[2] = nhwthread;
233 countsLocal[3] = ngpu;
236 MPI_Allreduce(countsLocal.data(), countsReduced.data(), countsLocal.size(), MPI_INT,
237 MPI_SUM, MPI_COMM_WORLD);
240 constexpr int numElementsMax = 11;
241 std::array<int, numElementsMax> maxMinReduced;
243 std::array<int, numElementsMax> maxMinLocal;
244 /* Store + and - values for all ranks,
245 * so we can get max+min with one MPI call.
247 maxMinLocal[0] = ncore;
248 maxMinLocal[1] = nhwthread;
249 maxMinLocal[2] = ngpu;
250 maxMinLocal[3] = static_cast<int>(gmx::simdSuggested(cpuInfo));
251 maxMinLocal[4] = gpu_hash;
252 maxMinLocal[5] = -maxMinLocal[0];
253 maxMinLocal[6] = -maxMinLocal[1];
254 maxMinLocal[7] = -maxMinLocal[2];
255 maxMinLocal[8] = -maxMinLocal[3];
256 maxMinLocal[9] = -maxMinLocal[4];
257 maxMinLocal[10] = (cpuIsAmdZen1 ? 1 : 0);
259 MPI_Allreduce(maxMinLocal.data(), maxMinReduced.data(), maxMinLocal.size(), MPI_INT,
260 MPI_MAX, MPI_COMM_WORLD);
263 hardwareInfo->nphysicalnode = countsReduced[0];
264 hardwareInfo->ncore_tot = countsReduced[1];
265 hardwareInfo->ncore_min = -maxMinReduced[5];
266 hardwareInfo->ncore_max = maxMinReduced[0];
267 hardwareInfo->nhwthread_tot = countsReduced[2];
268 hardwareInfo->nhwthread_min = -maxMinReduced[6];
269 hardwareInfo->nhwthread_max = maxMinReduced[1];
270 hardwareInfo->ngpu_compatible_tot = countsReduced[3];
271 hardwareInfo->ngpu_compatible_min = -maxMinReduced[7];
272 hardwareInfo->ngpu_compatible_max = maxMinReduced[2];
273 hardwareInfo->simd_suggest_min = -maxMinReduced[8];
274 hardwareInfo->simd_suggest_max = maxMinReduced[3];
275 hardwareInfo->bIdenticalGPUs = (maxMinReduced[4] == -maxMinReduced[9]);
276 hardwareInfo->haveAmdZen1Cpu = (maxMinReduced[10] > 0);
278 /* All ranks use the same pointer, protected by a mutex in the caller */
279 hardwareInfo->nphysicalnode = 1;
280 hardwareInfo->ncore_tot = ncore;
281 hardwareInfo->ncore_min = ncore;
282 hardwareInfo->ncore_max = ncore;
283 hardwareInfo->nhwthread_tot = hardwareInfo->nthreads_hw_avail;
284 hardwareInfo->nhwthread_min = hardwareInfo->nthreads_hw_avail;
285 hardwareInfo->nhwthread_max = hardwareInfo->nthreads_hw_avail;
286 hardwareInfo->ngpu_compatible_tot = hardwareInfo->gpu_info.n_dev_compatible;
287 hardwareInfo->ngpu_compatible_min = hardwareInfo->gpu_info.n_dev_compatible;
288 hardwareInfo->ngpu_compatible_max = hardwareInfo->gpu_info.n_dev_compatible;
289 hardwareInfo->simd_suggest_min = static_cast<int>(simdSuggested(cpuInfo));
290 hardwareInfo->simd_suggest_max = static_cast<int>(simdSuggested(cpuInfo));
291 hardwareInfo->bIdenticalGPUs = TRUE;
292 hardwareInfo->haveAmdZen1Cpu = cpuIsAmdZen1;
293 GMX_UNUSED_VALUE(physicalNodeComm);
297 /*! \brief Utility that does dummy computing for max 2 seconds to spin up cores
299 * This routine will check the number of cores configured and online
300 * (using sysconf), and the spins doing dummy compute operations for up to
301 * 2 seconds, or until all cores have come online. This can be used prior to
302 * hardware detection for platforms that take unused processors offline.
304 * This routine will not throw exceptions.
306 static void spinUpCore() noexcept
308 #if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF) && defined(_SC_NPROCESSORS_ONLN)
310 int countConfigured = sysconf(_SC_NPROCESSORS_CONF); // noexcept
311 auto start = std::chrono::steady_clock::now(); // noexcept
313 while (sysconf(_SC_NPROCESSORS_ONLN) < countConfigured
314 && std::chrono::steady_clock::now() - start < std::chrono::seconds(2))
316 for (int i = 1; i < 10000; i++)
324 printf("This cannot happen, but prevents loop from being optimized away.");
329 /*! \brief Prepare the system before hardware topology detection
331 * This routine should perform any actions we want to put the system in a state
332 * where we want it to be before detecting the hardware topology. For most
333 * processors there is nothing to do, but some architectures (in particular ARM)
334 * have support for taking configured cores offline, which will make them disappear
335 * from the online processor count.
337 * This routine checks if there is a mismatch between the number of cores
338 * configured and online, and in that case we issue a small workload that
339 * attempts to wake sleeping cores before doing the actual detection.
341 * This type of mismatch can also occur for x86 or PowerPC on Linux, if SMT has only
342 * been disabled in the kernel (rather than bios). Since those cores will never
343 * come online automatically, we currently skip this test for x86 & PowerPC to
344 * avoid wasting 2 seconds. We also skip the test if there is no thread support.
346 * \note Cores will sleep relatively quickly again, so it's important to issue
347 * the real detection code directly after this routine.
349 static void hardwareTopologyPrepareDetection()
351 #if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF) \
352 && (defined(THREAD_PTHREADS) || defined(THREAD_WINDOWS))
354 // Modify this conditional when/if x86 or PowerPC starts to sleep some cores
355 if (c_architecture != Architecture::X86 && c_architecture != Architecture::PowerPC)
357 int countConfigured = sysconf(_SC_NPROCESSORS_CONF);
358 std::vector<std::thread> workThreads(countConfigured);
360 for (auto& t : workThreads)
362 t = std::thread(spinUpCore);
365 for (auto& t : workThreads)
373 /*! \brief Sanity check hardware topology and print some notes to log
375 * \param mdlog Logger.
376 * \param hardwareTopology Reference to hardwareTopology object.
378 static void hardwareTopologyDoubleCheckDetection(const gmx::MDLogger gmx_unused& mdlog,
379 const gmx::HardwareTopology gmx_unused& hardwareTopology)
381 #if defined HAVE_SYSCONF && defined(_SC_NPROCESSORS_CONF)
382 if (hardwareTopology.supportLevel() < gmx::HardwareTopology::SupportLevel::LogicalProcessorCount)
387 int countFromDetection = hardwareTopology.machine().logicalProcessorCount;
388 int countConfigured = sysconf(_SC_NPROCESSORS_CONF);
390 /* BIOS, kernel or user actions can take physical processors
391 * offline. We already cater for the some of the cases inside the hardwareToplogy
392 * by trying to spin up cores just before we detect, but there could be other
393 * cases where it is worthwhile to hint that there might be more resources available.
395 if (countConfigured >= 0 && countConfigured != countFromDetection)
398 .appendTextFormatted(
399 "Note: %d CPUs configured, but only %d were detected to be online.\n",
400 countConfigured, countFromDetection);
402 if (c_architecture == Architecture::X86 && countConfigured == 2 * countFromDetection)
406 " X86 Hyperthreading is likely disabled; enable it for better "
409 // For PowerPC (likely Power8) it is possible to set SMT to either 2,4, or 8-way hardware threads.
410 // We only warn if it is completely disabled since default performance drops with SMT8.
411 if (c_architecture == Architecture::PowerPC && countConfigured == 8 * countFromDetection)
415 " PowerPC SMT is likely disabled; enable SMT2/SMT4 for better "
422 gmx_hw_info_t* gmx_detect_hardware(const gmx::MDLogger& mdlog, const PhysicalNodeCommunicator& physicalNodeComm)
424 // By construction, only one thread ever runs hardware detection,
425 // but we may as well prevent issues arising if that would change.
426 // Taking the lock early ensures that exactly one thread can
427 // attempt to construct g_hardwareInfo.
428 lock_guard<Mutex> lock(g_hardwareInfoMutex);
430 // If we already have the information, just return a handle to it.
431 if (g_hardwareInfo != nullptr)
433 return g_hardwareInfo.get();
436 // Make the new hardwareInfo in a temporary.
437 hardwareTopologyPrepareDetection();
439 // TODO: We should also do CPU hardware detection only once on each
440 // physical node and broadcast it, instead of doing it on every MPI rank.
441 auto hardwareInfo = std::make_unique<gmx_hw_info_t>(
442 std::make_unique<CpuInfo>(CpuInfo::detect()),
443 std::make_unique<HardwareTopology>(HardwareTopology::detect()));
445 // If we detected the topology on this system, double-check that it makes sense
446 if (hardwareInfo->hardwareTopology->isThisSystem())
448 hardwareTopologyDoubleCheckDetection(mdlog, *hardwareInfo->hardwareTopology);
451 // TODO: Get rid of this altogether.
452 hardwareInfo->nthreads_hw_avail = hardwareInfo->hardwareTopology->machine().logicalProcessorCount;
455 hardwareInfo->gpu_info.n_dev = 0;
456 hardwareInfo->gpu_info.n_dev_compatible = 0;
457 hardwareInfo->gpu_info.deviceInfo = nullptr;
459 gmx_detect_gpus(mdlog, physicalNodeComm, compat::make_not_null(hardwareInfo));
460 gmx_collect_hardware_mpi(*hardwareInfo->cpuInfo, physicalNodeComm, compat::make_not_null(hardwareInfo));
462 // Now that the temporary is fully constructed, swap it to become
464 g_hardwareInfo.swap(hardwareInfo);
466 return g_hardwareInfo.get();
469 bool compatibleGpusFound(const gmx_gpu_info_t& gpu_info)
471 return gpu_info.n_dev_compatible > 0;