1 #include "../../interface/sycldevice.hpp" 2 #include <csetjmp> // for MPI sycl device awareness 3 #include <csignal> // SIGSEGV 4 #include <vector> 5 #include <CL/sycl.hpp> 6 7 #if PetscDefined(USE_LOG) 8 PETSC_INTERN PetscErrorCode PetscLogInitialize(void); 9 #else 10 #define PetscLogInitialize() 0 11 #endif 12 13 namespace Petsc 14 { 15 16 namespace Device 17 { 18 19 namespace SYCL 20 { 21 22 // definition for static 23 std::array<Device::DeviceInternal*,PETSC_DEVICE_MAX_DEVICES> Device::devices_array_ = {}; 24 Device::DeviceInternal** Device::devices_ = &Device::devices_array_[1]; 25 int Device::defaultDevice_ = PETSC_SYCL_DEVICE_NONE; 26 bool Device::initialized_ = false; 27 28 static std::jmp_buf MPISyclAwareJumpBuffer; 29 static bool MPISyclAwareJumpBufferSet; 30 31 // internal "impls" class for SyclDevice. Each instance represents a single sycl device 32 class PETSC_NODISCARD Device::DeviceInternal 33 { 34 const int id_; // -1 for the host device; 0 and up for gpu devices 35 bool devInitialized_; 36 const sycl::device syclDevice_; 37 38 public: 39 // default constructor 40 DeviceInternal(int id) noexcept : id_(id),devInitialized_(false),syclDevice_(chooseSYCLDevice_(id)){} 41 int id() const {return id_;} 42 bool initialized() const {return devInitialized_;} 43 44 PETSC_NODISCARD PetscErrorCode initialize() noexcept 45 { 46 PetscFunctionBegin; 47 if (devInitialized_) PetscFunctionReturn(0); 48 if (syclDevice_.is_gpu() && use_gpu_aware_mpi) { 49 if (!isMPISyclAware_()) { 50 (*PetscErrorPrintf)("PETSc is configured with sycl support, but your MPI is not aware of sycl GPU devices. For better performance, please use a sycl GPU-aware MPI.\n"); 51 (*PetscErrorPrintf)("If you do not care, add option -use_gpu_aware_mpi 0. To not see the message again, add the option to your .petscrc, OR add it to the env var PETSC_OPTIONS.\n"); 52 PETSCABORT(PETSC_COMM_SELF,PETSC_ERR_LIB); 53 } 54 } 55 devInitialized_ = true; 56 PetscFunctionReturn(0); 57 } 58 59 PETSC_NODISCARD PetscErrorCode view(PetscViewer viewer) const noexcept 60 { 61 MPI_Comm comm; 62 PetscMPIInt rank; 63 PetscBool iascii; 64 65 PetscFunctionBegin; 66 PetscCheck(devInitialized_,PETSC_COMM_SELF,PETSC_ERR_COR,"Device %d being viewed before it was initialized or configured",id_); 67 PetscCall(PetscObjectTypeCompare(reinterpret_cast<PetscObject>(viewer),PETSCVIEWERASCII,&iascii)); 68 PetscCall(PetscObjectGetComm(reinterpret_cast<PetscObject>(viewer),&comm)); 69 if (iascii) { 70 PetscViewer sviewer; 71 72 PetscCallMPI(MPI_Comm_rank(comm,&rank)); 73 PetscCall(PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&sviewer)); 74 PetscCall(PetscViewerASCIIPrintf(sviewer,"[%d] device: %s\n",rank,syclDevice_.get_info<sycl::info::device::name>().c_str())); 75 PetscCall(PetscViewerASCIIPushTab(sviewer)); 76 PetscCall(PetscViewerASCIIPrintf(sviewer,"-> Device vendor: %s\n",syclDevice_.get_info<sycl::info::device::vendor>().c_str())); 77 PetscCall(PetscViewerASCIIPopTab(sviewer)); 78 PetscCall(PetscViewerFlush(sviewer)); 79 PetscCall(PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&sviewer)); 80 PetscCall(PetscViewerFlush(viewer)); 81 } 82 PetscFunctionReturn(0); 83 } 84 85 private: 86 static sycl::device chooseSYCLDevice_(int id) 87 { 88 if (id == PETSC_SYCL_DEVICE_HOST) { 89 return sycl::device(sycl::host_selector()); 90 } else { 91 return sycl::device::get_devices(sycl::info::device_type::gpu)[id]; 92 } 93 } 94 95 // Is the underlying MPI aware of sycl (GPU) devices? 96 bool isMPISyclAware_() noexcept 97 { 98 const int bufSize = 2; 99 const int hbuf[bufSize] = {1,0}; 100 int *dbuf = nullptr; 101 bool awareness = false; 102 const auto SyclSignalHandler = [](int signal, void *ptr) -> PetscErrorCode { 103 if ((signal == SIGSEGV) && MPISyclAwareJumpBufferSet) std::longjmp(MPISyclAwareJumpBuffer,1); 104 return PetscSignalHandlerDefault(signal,ptr); 105 }; 106 107 PetscFunctionBegin; 108 auto Q = sycl::queue(syclDevice_); 109 dbuf = sycl::malloc_device<int>(bufSize,Q); 110 Q.memcpy(dbuf,hbuf,sizeof(int)*bufSize).wait(); 111 PetscCallAbort(PETSC_COMM_SELF,PetscPushSignalHandler(SyclSignalHandler,nullptr)); 112 MPISyclAwareJumpBufferSet = true; 113 if (setjmp(MPISyclAwareJumpBuffer)) { 114 // if a segv was triggered in the MPI_Allreduce below, it is very likely due to MPI not being GPU-aware 115 awareness = false; 116 PetscStackPop; 117 } else if (!MPI_Allreduce(dbuf,dbuf+1,1,MPI_INT,MPI_SUM,PETSC_COMM_SELF)) awareness = true; 118 MPISyclAwareJumpBufferSet = false; 119 PetscCallAbort(PETSC_COMM_SELF,PetscPopSignalHandler()); 120 sycl::free(dbuf,Q); 121 PetscFunctionReturn(awareness); 122 } 123 }; 124 125 PetscErrorCode Device::initialize(MPI_Comm comm, PetscInt *defaultDeviceId, PetscDeviceInitType *defaultInitType) noexcept 126 { 127 PetscInt initType = *defaultInitType,id = *defaultDeviceId; 128 PetscBool view = PETSC_FALSE,flg; 129 PetscInt ngpus; 130 PetscErrorCode ierr; 131 132 PetscFunctionBegin; 133 if (initialized_) PetscFunctionReturn(0); 134 initialized_ = true; 135 PetscCall(PetscRegisterFinalize(finalize_)); 136 137 ierr = PetscOptionsBegin(comm,nullptr,"PetscDevice SYCL Options","Sys");PetscCall(ierr); 138 PetscCall(PetscOptionsEList("-device_enable_sycl","How (or whether) to initialize a device","SyclDevice::initialize()",PetscDeviceInitTypes,3,PetscDeviceInitTypes[initType],&initType,nullptr)); 139 PetscCall(PetscOptionsRangeInt("-device_select_sycl","Which sycl device to use? Pass -2 for host, PETSC_DECIDE (-1) to let PETSc decide, 0 and up for GPUs","PetscDeviceCreate",id,&id,nullptr,-2,std::numeric_limits<decltype(ngpus)>::max())); 140 PetscCall(PetscOptionsBool("-device_view_sycl","Display device information and assignments (forces eager initialization)",nullptr,view,&view,&flg)); 141 ierr = PetscOptionsEnd();PetscCall(ierr); 142 143 // post-process the options and lay the groundwork for initialization if needs be 144 std::vector<sycl::device> gpu_devices = sycl::device::get_devices(sycl::info::device_type::gpu); 145 ngpus = static_cast<PetscInt>(gpu_devices.size()); 146 PetscCheckFalse(ngpus == 0 && id >= 0,comm,PETSC_ERR_USER_INPUT,"You specified a sycl gpu device with -device_select_sycl %d but there is no GPU", (int)id); 147 PetscCheckFalse(ngpus > 0 && id >= ngpus,comm,PETSC_ERR_USER_INPUT,"You specified a sycl gpu device with -device_select_sycl %d but there are only %d GPU", (int)id, (int)ngpus); 148 149 if (initType == PETSC_DEVICE_INIT_NONE) id = PETSC_SYCL_DEVICE_NONE; /* user wants to disable all sycl devices */ 150 else { 151 PetscCall(PetscDeviceCheckDeviceCount_Internal(ngpus)); 152 if (id == PETSC_DECIDE) { /* petsc will choose a GPU device if any, otherwise a CPU device */ 153 if (ngpus) { 154 PetscMPIInt rank; 155 PetscCallMPI(MPI_Comm_rank(comm,&rank)); 156 id = rank % ngpus; 157 } else id = PETSC_SYCL_DEVICE_HOST; 158 } 159 view = static_cast<decltype(view)>(view && flg); 160 if (view) initType = PETSC_DEVICE_INIT_EAGER; 161 } 162 163 if (id == -2) id = PETSC_SYCL_DEVICE_HOST; // user passed in '-device_select_sycl -2'. We transform it into canonical form 164 165 defaultDevice_ = static_cast<decltype(defaultDevice_)>(id); 166 PetscCheckFalse(initType == PETSC_DEVICE_INIT_EAGER && id == PETSC_SYCL_DEVICE_NONE,comm,PETSC_ERR_USER_INPUT,"Cannot eagerly initialize sycl devices as you disabled them by -device_enable_sycl none"); 167 168 if (initType == PETSC_DEVICE_INIT_EAGER) { 169 devices_[defaultDevice_] = new DeviceInternal(defaultDevice_); 170 PetscCall(devices_[defaultDevice_]->initialize()); 171 if (view) { 172 PetscViewer viewer; 173 PetscCall(PetscLogInitialize()); 174 PetscCall(PetscViewerASCIIGetStdout(comm,&viewer)); 175 PetscCall(devices_[defaultDevice_]->view(viewer)); 176 } 177 } 178 179 // record the results of the initialization 180 *defaultInitType = static_cast<PetscDeviceInitType>(initType); 181 *defaultDeviceId = id; 182 PetscFunctionReturn(0); 183 } 184 185 PetscErrorCode Device::finalize_() noexcept 186 { 187 PetscFunctionBegin; 188 if (!initialized_) PetscFunctionReturn(0); 189 for (auto&& devPtr : devices_array_) delete devPtr; 190 defaultDevice_ = PETSC_SYCL_DEVICE_NONE; // disabled by default 191 initialized_ = false; 192 PetscFunctionReturn(0); 193 } 194 195 PetscErrorCode Device::getDevice(PetscDevice device, PetscInt id) const noexcept 196 { 197 PetscFunctionBegin; 198 PetscCheckFalse(defaultDevice_ == PETSC_SYCL_DEVICE_NONE,PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Trying to retrieve a SYCL PetscDevice when it has been disabled"); 199 if (id == PETSC_DECIDE) id = defaultDevice_; 200 PetscCheckFalse((id < PETSC_SYCL_DEVICE_HOST) || (id-PETSC_SYCL_DEVICE_HOST >= PETSC_DEVICE_MAX_DEVICES),PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Only supports %zu number of devices but trying to get device with id %" PetscInt_FMT,devices_array_.size(),id); 201 if (devices_[id]) { 202 PetscCheckFalse(id != devices_[id]->id(),PETSC_COMM_SELF,PETSC_ERR_PLIB,"Entry %" PetscInt_FMT " contains device with mismatching id %" PetscInt_FMT,id,devices_[id]->id()); 203 } else devices_[id] = new DeviceInternal(id); 204 PetscCall(devices_[id]->initialize()); 205 device->deviceId = devices_[id]->id(); // technically id = devices_[id]->id_ here 206 device->ops->createcontext = create_; 207 device->ops->configure = this->configureDevice; 208 device->ops->view = this->viewDevice; 209 PetscFunctionReturn(0); 210 } 211 212 PetscErrorCode Device::configureDevice(PetscDevice device) noexcept 213 { 214 PetscFunctionBegin; 215 // Nothing for now 216 PetscFunctionReturn(0); 217 } 218 219 PetscErrorCode Device::viewDevice(PetscDevice device, PetscViewer viewer) noexcept 220 { 221 PetscFunctionBegin; 222 PetscCall(devices_[device->deviceId]->view(viewer)); 223 PetscFunctionReturn(0); 224 } 225 226 } // namespace SYCL 227 228 } // namespace Device 229 230 } // namespace Petsc 231