[UR][L0] Restrict USM residency to peers with enabled P2P access#21889
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ldorau wants to merge 4 commits intointel:syclfrom
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[UR][L0] Restrict USM residency to peers with enabled P2P access#21889ldorau wants to merge 4 commits intointel:syclfrom
ldorau wants to merge 4 commits intointel:syclfrom
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Pull request overview
Implements peer-access–driven memory residency management for the Level Zero v2 adapter, wiring ext_oneapi_enable_peer_access/disable through UR to update USM pool residency, and adjusting SYCL’s peer-access API to avoid cross-platform usage.
Changes:
- Add L0 v2 peer-access implementation that toggles per-device peer state and propagates residency updates to all tracked contexts.
- Extend USM pool/provider plumbing to support runtime resident-device changes and add pool-manager iteration helpers.
- Update SYCL peer-access enable/disable to validate platforms; add initial (currently placeholder) UR tests.
Reviewed changes
Copilot reviewed 18 out of 18 changed files in this pull request and generated 14 comments.
Show a summary per file
| File | Description |
|---|---|
| unified-runtime/test/adapters/level_zero/v2/memory_residency.cpp | Adds multi-device residency tests for peer-access (currently placeholders). |
| unified-runtime/source/common/ur_pool_manager.hpp | Adds descriptor helpers and pool-manager iteration with descriptor access. |
| unified-runtime/source/common/backtrace_lin.cpp | Introduces a constant for max backtrace frames. |
| unified-runtime/source/adapters/level_zero/v2/usm_p2p.cpp | New L0 v2 implementation for peer access enable/disable/info and context propagation. |
| unified-runtime/source/adapters/level_zero/v2/usm.hpp | Exposes USM pool API to change resident devices. |
| unified-runtime/source/adapters/level_zero/v2/usm.cpp | Updates provider creation to use peer-enabled residency model and adds residency-change plumbing. |
| unified-runtime/source/adapters/level_zero/v2/memory.cpp | Switches P2P eligibility check to the new “enabled peers” model. |
| unified-runtime/source/adapters/level_zero/v2/context.hpp | Adds APIs to query enabled peer relationships and to propagate residency changes. |
| unified-runtime/source/adapters/level_zero/v2/context.cpp | Removes precomputed P2P tables; tracks contexts; adds peer-access query helpers and residency propagation. |
| unified-runtime/source/adapters/level_zero/usm_p2p.cpp | Updates v1 behavior to log enable/disable as ignored (always enabled). |
| unified-runtime/source/adapters/level_zero/platform.hpp | Updates platform comment to reflect v2 peer-access usage of tracked contexts. |
| unified-runtime/source/adapters/level_zero/platform.cpp | Initializes per-device peer tables based on L0 P2P capability/properties. |
| unified-runtime/source/adapters/level_zero/device.hpp | Adds peer-status table to devices and stream operators. |
| unified-runtime/source/adapters/level_zero/device.cpp | Implements stream operators for device id and peer status. |
| unified-runtime/source/adapters/level_zero/context.cpp | Minor comment adjustment around context tracking in v1. |
| unified-runtime/source/adapters/level_zero/CMakeLists.txt | Moves usm_p2p.cpp into the v2 adapter build. |
| sycl/source/device.cpp | Adds same-platform validation for enable/disable peer access calls. |
| .github/copilot-instructions.md | Expands repository instructions/documentation for Copilot usage. |
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Please review @intel/llvm-reviewers-runtime @intel/unified-runtime-reviewers @intel/unified-runtime-reviewers-level-zero |
kswiecicki
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- Skip peers with disabled P2P in makeProvider (USM pool creation) - Add urUsmP2PEnablePeerAccessExp / urUsmP2PDisablePeerAccessExp - Track per-device peer status in ur_device_handle_t_::peers[] - Update existing USM pool residency on P2P enable/disable Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
kswiecicki
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May 7, 2026
- Fill in three placeholder multi-device tests in memory_residency.cpp - Tests verify P2P-driven residency: absent-on-peer without P2P, enable/disable state machine checks, end-to-end data transfer Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
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Please review @lslusarczyk |
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@intel/llvm-gatekeepers please consider merging |
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Do not merge yet - waiting for review from @lslusarczyk. |
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Additional SYCL e2e test is in the separate PR yet: #21944 |
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@intel/llvm-gatekeepers please consider merging |
lslusarczyk
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May 11, 2026
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a few cosmetics comments, apply or ignore - as you wish
change is OK
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both functions differ by just a type of call
please create template helper function, templated by detail::UrApiKind::urUsmP2PDisablePeerAccessExp / detail::UrApiKind::urUsmP2PEnablePeerAccessExp
use helper function in both functions
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no reason to leave *phContext = nullptr outside 'try {' and no reason keeping other statements before ZE2UR_CALL inside 'try'
please either move try to the beginning or move try just before ZE2UR_CALL
Extract common logic from ext_oneapi_enable_peer_access and ext_oneapi_disable_peer_access into a templated p2pAccessHelper function to avoid code duplication. Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
The disablePeerAccessStateMachineAndSourceAllocationPersists test was failing intermittently because deferred frees from the preceding test complete asynchronously, causing UR_DEVICE_INFO_GLOBAL_MEM_FREE to report more free memory than the baseline captured at the start of the test. Remove the unreliable source-device free-memory assertion and the allocation it required, keeping only the state-machine checks (disable succeeds, double-disable returns UR_RESULT_ERROR_INVALID_OPERATION). The source-device allocation property is already covered by allocatingDeviceMemoryWillResultInOOM which runs first in isolation.
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Do not merge it yet, please |
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Co-authored-by: Łukasz Ślusarczyk <lukasz.slusarczyk at intel.com>
Co-authored-by: Lukasz Dorau <lukasz.dorau at intel.com>