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37 #include "detecthardware.h"
49 #include "gromacs/compat/pointers.h"
50 #include "gromacs/gpu_utils/gpu_utils.h"
51 #include "gromacs/hardware/cpuinfo.h"
52 #include "gromacs/hardware/hardwaretopology.h"
53 #include "gromacs/hardware/hw_info.h"
54 #include "gromacs/simd/support.h"
55 #include "gromacs/utility/basedefinitions.h"
56 #include "gromacs/utility/basenetwork.h"
57 #include "gromacs/utility/baseversion.h"
58 #include "gromacs/utility/cstringutil.h"
59 #include "gromacs/utility/exceptions.h"
60 #include "gromacs/utility/fatalerror.h"
61 #include "gromacs/utility/gmxassert.h"
62 #include "gromacs/utility/logger.h"
63 #include "gromacs/utility/mutex.h"
64 #include "gromacs/utility/physicalnodecommunicator.h"
66 #include "architecture.h"
69 # include <unistd.h> // sysconf()
72 gmx_hw_info_t::gmx_hw_info_t(std::unique_ptr
<gmx::CpuInfo
> cpuInfo
,
73 std::unique_ptr
<gmx::HardwareTopology
> hardwareTopology
)
74 : cpuInfo(std::move(cpuInfo
)),
75 hardwareTopology(std::move(hardwareTopology
))
79 gmx_hw_info_t::~gmx_hw_info_t()
81 free_gpu_info(&gpu_info
);
87 //! Convenience macro to help us avoid ifdefs each time we use sysconf
88 #if !defined(_SC_NPROCESSORS_ONLN) && defined(_SC_NPROC_ONLN)
89 # define _SC_NPROCESSORS_ONLN _SC_NPROC_ONLN
92 //! Convenience macro to help us avoid ifdefs each time we use sysconf
93 #if !defined(_SC_NPROCESSORS_CONF) && defined(_SC_NPROC_CONF)
94 # define _SC_NPROCESSORS_CONF _SC_NPROC_CONF
97 /*! \brief Information about the hardware of all nodes (common to all threads in this process).
99 * This information is constructed only when required, but thereafter
100 * its lifetime is that of the whole process, potentially across
101 * multiple successive simulation parts. It's wise to ensure that only
102 * one thread can create the information, but thereafter they can all
103 * read it without e.g. needing a std::shared_ptr to ensure its
104 * lifetime exceeds that of the thread. */
105 static std::unique_ptr
<gmx_hw_info_t
> g_hardwareInfo
;
106 //! A mutex to protect the hwinfo structure
107 static Mutex g_hardwareInfoMutex
;
109 //! Detect GPUs, if that makes sense to attempt.
110 static void gmx_detect_gpus(const gmx::MDLogger
&mdlog
,
111 const PhysicalNodeCommunicator
&physicalNodeComm
,
112 compat::not_null
<gmx_hw_info_t
*> hardwareInfo
)
114 hardwareInfo
->gpu_info
.bDetectGPUs
= canPerformGpuDetection();
116 if (!hardwareInfo
->gpu_info
.bDetectGPUs
)
121 bool isMasterRankOfPhysicalNode
= true;
123 isMasterRankOfPhysicalNode
= (physicalNodeComm
.rank_
== 0);
125 // We choose to run the detection only once with thread-MPI and
126 // use a mutex to enforce it.
127 GMX_UNUSED_VALUE(physicalNodeComm
);
128 isMasterRankOfPhysicalNode
= true;
131 /* The OpenCL support requires us to run detection on all ranks.
132 * With CUDA we don't need to, and prefer to detect on one rank
133 * and send the information to the other ranks over MPI. */
134 bool allRanksMustDetectGpus
= (GMX_GPU
== GMX_GPU_OPENCL
);
135 bool gpusCanBeDetected
= false;
136 if (isMasterRankOfPhysicalNode
|| allRanksMustDetectGpus
)
138 std::string errorMessage
;
139 gpusCanBeDetected
= isGpuDetectionFunctional(&errorMessage
);
140 if (!gpusCanBeDetected
)
142 GMX_LOG(mdlog
.info
).asParagraph().appendTextFormatted(
143 "NOTE: Detection of GPUs failed. The API reported:\n"
145 " GROMACS cannot run tasks on a GPU.",
146 errorMessage
.c_str());
150 if (gpusCanBeDetected
)
152 findGpus(&hardwareInfo
->gpu_info
);
153 // No need to tell the user anything at this point, they get a
154 // hardware report later.
158 if (!allRanksMustDetectGpus
)
160 /* Broadcast the GPU info to the other ranks within this node */
161 MPI_Bcast(&hardwareInfo
->gpu_info
.n_dev
, 1, MPI_INT
, 0, physicalNodeComm
.comm_
);
163 if (hardwareInfo
->gpu_info
.n_dev
> 0)
167 dev_size
= hardwareInfo
->gpu_info
.n_dev
*sizeof_gpu_dev_info();
169 if (!isMasterRankOfPhysicalNode
)
171 hardwareInfo
->gpu_info
.gpu_dev
=
172 (struct gmx_device_info_t
*)malloc(dev_size
);
174 MPI_Bcast(hardwareInfo
->gpu_info
.gpu_dev
, dev_size
, MPI_BYTE
,
175 0, physicalNodeComm
.comm_
);
176 MPI_Bcast(&hardwareInfo
->gpu_info
.n_dev_compatible
, 1, MPI_INT
,
177 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
&&
194 cpuInfo
.family() == 23 &&
195 (cpuInfo
.model() == 1 || cpuInfo
.model() == 17 ||
196 cpuInfo
.model() == 8 || cpuInfo
.model() == 24)) ||
197 cpuInfo
.vendor() == CpuInfo::Vendor::Hygon
);
199 int nhwthread
, ngpu
, i
;
202 nhwthread
= hardwareInfo
->nthreads_hw_avail
;
203 ngpu
= hardwareInfo
->gpu_info
.n_dev_compatible
;
204 /* Create a unique hash of the GPU type(s) in this node */
206 /* Here it might be better to only loop over the compatible GPU, but we
207 * don't have that information available and it would also require
208 * removing the device ID from the device info string.
210 for (i
= 0; i
< hardwareInfo
->gpu_info
.n_dev
; i
++)
214 /* Since the device ID is incorporated in the hash, the order of
215 * the GPUs affects the hash. Also two identical GPUs won't give
216 * a gpu_hash of zero after XORing.
218 get_gpu_device_info_string(stmp
, hardwareInfo
->gpu_info
, i
);
219 gpu_hash
^= gmx_string_fullhash_func(stmp
, gmx_string_hash_init
);
222 constexpr int numElementsCounts
= 4;
223 std::array
<int, numElementsCounts
> countsReduced
;
225 std::array
<int, numElementsCounts
> countsLocal
= {{0}};
226 // Organize to sum values from only one rank within each node,
227 // so we get the sum over all nodes.
228 bool isMasterRankOfPhysicalNode
= (physicalNodeComm
.rank_
== 0);
229 if (isMasterRankOfPhysicalNode
)
232 countsLocal
[1] = ncore
;
233 countsLocal
[2] = nhwthread
;
234 countsLocal
[3] = ngpu
;
237 MPI_Allreduce(countsLocal
.data(), countsReduced
.data(), countsLocal
.size(),
238 MPI_INT
, MPI_SUM
, MPI_COMM_WORLD
);
241 constexpr int numElementsMax
= 11;
242 std::array
<int, numElementsMax
> maxMinReduced
;
244 std::array
<int, numElementsMax
> maxMinLocal
;
245 /* Store + and - values for all ranks,
246 * so we can get max+min with one MPI call.
248 maxMinLocal
[0] = ncore
;
249 maxMinLocal
[1] = nhwthread
;
250 maxMinLocal
[2] = ngpu
;
251 maxMinLocal
[3] = static_cast<int>(gmx::simdSuggested(cpuInfo
));
252 maxMinLocal
[4] = gpu_hash
;
253 maxMinLocal
[5] = -maxMinLocal
[0];
254 maxMinLocal
[6] = -maxMinLocal
[1];
255 maxMinLocal
[7] = -maxMinLocal
[2];
256 maxMinLocal
[8] = -maxMinLocal
[3];
257 maxMinLocal
[9] = -maxMinLocal
[4];
258 maxMinLocal
[10] = (cpuIsAmdZen1
? 1 : 0);
260 MPI_Allreduce(maxMinLocal
.data(), maxMinReduced
.data(), maxMinLocal
.size(),
261 MPI_INT
, MPI_MAX
, MPI_COMM_WORLD
);
264 hardwareInfo
->nphysicalnode
= countsReduced
[0];
265 hardwareInfo
->ncore_tot
= countsReduced
[1];
266 hardwareInfo
->ncore_min
= -maxMinReduced
[5];
267 hardwareInfo
->ncore_max
= maxMinReduced
[0];
268 hardwareInfo
->nhwthread_tot
= countsReduced
[2];
269 hardwareInfo
->nhwthread_min
= -maxMinReduced
[6];
270 hardwareInfo
->nhwthread_max
= maxMinReduced
[1];
271 hardwareInfo
->ngpu_compatible_tot
= countsReduced
[3];
272 hardwareInfo
->ngpu_compatible_min
= -maxMinReduced
[7];
273 hardwareInfo
->ngpu_compatible_max
= maxMinReduced
[2];
274 hardwareInfo
->simd_suggest_min
= -maxMinReduced
[8];
275 hardwareInfo
->simd_suggest_max
= maxMinReduced
[3];
276 hardwareInfo
->bIdenticalGPUs
= (maxMinReduced
[4] == -maxMinReduced
[9]);
277 hardwareInfo
->haveAmdZen1Cpu
= (maxMinReduced
[10] > 0);
279 /* All ranks use the same pointer, protected by a mutex in the caller */
280 hardwareInfo
->nphysicalnode
= 1;
281 hardwareInfo
->ncore_tot
= ncore
;
282 hardwareInfo
->ncore_min
= ncore
;
283 hardwareInfo
->ncore_max
= ncore
;
284 hardwareInfo
->nhwthread_tot
= hardwareInfo
->nthreads_hw_avail
;
285 hardwareInfo
->nhwthread_min
= hardwareInfo
->nthreads_hw_avail
;
286 hardwareInfo
->nhwthread_max
= hardwareInfo
->nthreads_hw_avail
;
287 hardwareInfo
->ngpu_compatible_tot
= hardwareInfo
->gpu_info
.n_dev_compatible
;
288 hardwareInfo
->ngpu_compatible_min
= hardwareInfo
->gpu_info
.n_dev_compatible
;
289 hardwareInfo
->ngpu_compatible_max
= hardwareInfo
->gpu_info
.n_dev_compatible
;
290 hardwareInfo
->simd_suggest_min
= static_cast<int>(simdSuggested(cpuInfo
));
291 hardwareInfo
->simd_suggest_max
= static_cast<int>(simdSuggested(cpuInfo
));
292 hardwareInfo
->bIdenticalGPUs
= TRUE
;
293 hardwareInfo
->haveAmdZen1Cpu
= cpuIsAmdZen1
;
294 GMX_UNUSED_VALUE(physicalNodeComm
);
298 /*! \brief Utility that does dummy computing for max 2 seconds to spin up cores
300 * This routine will check the number of cores configured and online
301 * (using sysconf), and the spins doing dummy compute operations for up to
302 * 2 seconds, or until all cores have come online. This can be used prior to
303 * hardware detection for platforms that take unused processors offline.
305 * This routine will not throw exceptions.
308 spinUpCore() noexcept
310 #if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF) && defined(_SC_NPROCESSORS_ONLN)
312 int countConfigured
= sysconf(_SC_NPROCESSORS_CONF
); // noexcept
313 auto start
= std::chrono::steady_clock::now(); // noexcept
315 while (sysconf(_SC_NPROCESSORS_ONLN
) < countConfigured
&&
316 std::chrono::steady_clock::now() - start
< std::chrono::seconds(2))
318 for (int i
= 1; i
< 10000; i
++)
326 printf("This cannot happen, but prevents loop from being optimized away.");
331 /*! \brief Prepare the system before hardware topology detection
333 * This routine should perform any actions we want to put the system in a state
334 * where we want it to be before detecting the hardware topology. For most
335 * processors there is nothing to do, but some architectures (in particular ARM)
336 * have support for taking configured cores offline, which will make them disappear
337 * from the online processor count.
339 * This routine checks if there is a mismatch between the number of cores
340 * configured and online, and in that case we issue a small workload that
341 * attempts to wake sleeping cores before doing the actual detection.
343 * This type of mismatch can also occur for x86 or PowerPC on Linux, if SMT has only
344 * been disabled in the kernel (rather than bios). Since those cores will never
345 * come online automatically, we currently skip this test for x86 & PowerPC to
346 * avoid wasting 2 seconds. We also skip the test if there is no thread support.
348 * \note Cores will sleep relatively quickly again, so it's important to issue
349 * the real detection code directly after this routine.
352 hardwareTopologyPrepareDetection()
354 #if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF) && \
355 (defined(THREAD_PTHREADS) || defined(THREAD_WINDOWS))
357 // Modify this conditional when/if x86 or PowerPC starts to sleep some cores
358 if (c_architecture
!= Architecture::X86
&&
359 c_architecture
!= Architecture::PowerPC
)
361 int countConfigured
= sysconf(_SC_NPROCESSORS_CONF
);
362 std::vector
<std::thread
> workThreads(countConfigured
);
364 for (auto &t
: workThreads
)
366 t
= std::thread(spinUpCore
);
369 for (auto &t
: workThreads
)
377 /*! \brief Sanity check hardware topology and print some notes to log
379 * \param mdlog Logger.
380 * \param hardwareTopology Reference to hardwareTopology object.
383 hardwareTopologyDoubleCheckDetection(const gmx::MDLogger gmx_unused
&mdlog
,
384 const gmx::HardwareTopology gmx_unused
&hardwareTopology
)
386 #if defined HAVE_SYSCONF && defined(_SC_NPROCESSORS_CONF)
387 if (hardwareTopology
.supportLevel() < gmx::HardwareTopology::SupportLevel::LogicalProcessorCount
)
392 int countFromDetection
= hardwareTopology
.machine().logicalProcessorCount
;
393 int countConfigured
= sysconf(_SC_NPROCESSORS_CONF
);
395 /* BIOS, kernel or user actions can take physical processors
396 * offline. We already cater for the some of the cases inside the hardwareToplogy
397 * by trying to spin up cores just before we detect, but there could be other
398 * cases where it is worthwhile to hint that there might be more resources available.
400 if (countConfigured
>= 0 && countConfigured
!= countFromDetection
)
403 appendTextFormatted("Note: %d CPUs configured, but only %d were detected to be online.\n", countConfigured
, countFromDetection
);
405 if (c_architecture
== Architecture::X86
&&
406 countConfigured
== 2*countFromDetection
)
409 appendText(" X86 Hyperthreading is likely disabled; enable it for better performance.");
411 // For PowerPC (likely Power8) it is possible to set SMT to either 2,4, or 8-way hardware threads.
412 // We only warn if it is completely disabled since default performance drops with SMT8.
413 if (c_architecture
== Architecture::PowerPC
&&
414 countConfigured
== 8*countFromDetection
)
417 appendText(" PowerPC SMT is likely disabled; enable SMT2/SMT4 for better performance.");
423 gmx_hw_info_t
*gmx_detect_hardware(const gmx::MDLogger
&mdlog
,
424 const PhysicalNodeCommunicator
&physicalNodeComm
)
426 // By construction, only one thread ever runs hardware detection,
427 // but we may as well prevent issues arising if that would change.
428 // Taking the lock early ensures that exactly one thread can
429 // attempt to construct g_hardwareInfo.
430 lock_guard
<Mutex
> lock(g_hardwareInfoMutex
);
432 // If we already have the information, just return a handle to it.
433 if (g_hardwareInfo
!= nullptr)
435 return g_hardwareInfo
.get();
438 // Make the new hardwareInfo in a temporary.
439 hardwareTopologyPrepareDetection();
441 // TODO: We should also do CPU hardware detection only once on each
442 // physical node and broadcast it, instead of doing it on every MPI rank.
443 auto hardwareInfo
= std::make_unique
<gmx_hw_info_t
>(std::make_unique
<CpuInfo
>(CpuInfo::detect()),
444 std::make_unique
<HardwareTopology
>(HardwareTopology::detect()));
446 // If we detected the topology on this system, double-check that it makes sense
447 if (hardwareInfo
->hardwareTopology
->isThisSystem())
449 hardwareTopologyDoubleCheckDetection(mdlog
, *hardwareInfo
->hardwareTopology
);
452 // TODO: Get rid of this altogether.
453 hardwareInfo
->nthreads_hw_avail
= hardwareInfo
->hardwareTopology
->machine().logicalProcessorCount
;
456 hardwareInfo
->gpu_info
.n_dev
= 0;
457 hardwareInfo
->gpu_info
.n_dev_compatible
= 0;
458 hardwareInfo
->gpu_info
.gpu_dev
= nullptr;
460 gmx_detect_gpus(mdlog
, physicalNodeComm
, compat::make_not_null(hardwareInfo
));
461 gmx_collect_hardware_mpi(*hardwareInfo
->cpuInfo
, physicalNodeComm
, compat::make_not_null(hardwareInfo
));
463 // Now that the temporary is fully constructed, swap it to become
465 g_hardwareInfo
.swap(hardwareInfo
);
467 return g_hardwareInfo
.get();
470 bool compatibleGpusFound(const gmx_gpu_info_t
&gpu_info
)
472 return gpu_info
.n_dev_compatible
> 0;