memory resident limit to enabled peers #19257
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| ZeOffsetToImageHandleMap; | ||
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| // devices which user enabled p2p access by urUsmP2P(Enable|Disable)PeerAccessExp | ||
| std::unordered_set<DeviceId> p2pDeviceIds; |
| { | ||
| std::scoped_lock<ur_shared_mutex> Lock(Platform->ContextsMutex); | ||
| auto It = std::find(Contexts.begin(), Contexts.end(), hContext); | ||
| UR_ASSERT(It != Contexts.end(), UR_RESULT_ERROR_INVALID_CONTEXT); |
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can this happen? should this be just a regular assert?
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| void cleanupPools(); | ||
| void cleanupPoolsForQueue(void *hQueue); | ||
| void addResidentDevice(ur_device_handle_t hDevice, ur_device_handle_t peerDevice); |
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Where is this function called from?
| continue; | ||
| } | ||
| | ||
| if (!p2pDevicesEnabledByUser.has_value()) |
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Why isn't this outside of the loop?
| { | ||
| std::scoped_lock<ur_shared_mutex> Lock(Platform->ContextsMutex); | ||
| for (auto Context : Platform->Contexts) { | ||
| Context->addResidentDevice(commandDevice, peerDevice); |
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What if some context does not contain commandDevice?
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| assert(0 = std::count_if( | ||
| std::begin(pDevices), std::end(pDevices), | ||
| [&](const auto pDevice) { return newPeerDevice->Id == pDevice->Id; })); |
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cuCtxEnablePeerAccess returns CUDA_ERROR_PEER_ACCESS_ALREADY_ENABLED. Could we have this error mapped to a UR error? It would help make the peer-to-peer SYCL API more consistent (See #19787.)
lslusarczyk force-pushed the memresident branch from ab67572 to f1124c5 Compare lslusarczyk had a problem deploying to WindowsCILock GitHub Actions Failure 
Will be required for intel/llvm#19257
| FYI, when you start requiring the new function from UMF v1.1.x please remember to update min. required version -> ref. #20334 |
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By default, the Level Zero adapter makes all device allocations resident on all "peer" devices, even if the application doesn't use those peer devices at all. USM residency adds significant overhead.
For v2 unfied-runtime adapter we switch in this PR to not calling zeContextMakeMemoryResident on all devices in the context, just the one that was specified during allocation and those specified using ext_oneapi_enable_peer_access.
When ext_oneapi_enable_peer_access / ext_oneapi_disable_peer_access is called, we retroactively call zeContextMakeMemoryResident or zeContextEvictMemory respectively, on all the active pages in the heap. This is done by calling ctl call in UMF drafted here: oneapi-src/unified-memory-framework@e6d5043
UMF part was done in oneapi-src/unified-memory-framework#1517