Fix NVML memory reporting regression on coherent UMA platforms#1611
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parallelArchitect wants to merge 1 commit intoaristocratos:mainfrom
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Fix NVML memory reporting regression on coherent UMA platforms#1611parallelArchitect wants to merge 1 commit intoaristocratos:mainfrom
parallelArchitect wants to merge 1 commit intoaristocratos:mainfrom
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On GB10 / DGX Spark, nvmlDeviceGetMemoryInfo returns NVML_SUCCESS with total == system MemTotal (~121GB). This prevents correct UMA detection, causing incorrect VRAM reporting. Fix: detect UMA by comparing NVML total against /proc/meminfo MemTotal. If total >= 90% of system RAM, classify as unified memory and use MemAvailable instead of MemTotal for display. Also fix GCC 13 compatibility by replacing std::ranges::to with equivalent C++20 constructs. Note: requires validation on GB10 / DGX Spark hardware. Author does not have access to a coherent UMA system.
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For anyone needing the NVML memory fix now while this PR is under review — the fix is available in this fork: https://github.com/parallelArchitect/nvml-unified-shim |
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On GB10 / DGX Spark, nvmlDeviceGetMemoryInfo returns NVML_SUCCESS with total == system MemTotal (~121GB). This prevents correct UMA detection, causing incorrect VRAM reporting.
Fix: detect UMA by comparing NVML total against /proc/meminfo MemTotal. If total >= 90% of system RAM, classify as unified memory and use MemAvailable instead of MemTotal for display.
Also fix GCC 13 compatibility by replacing std::ranges::to with equivalent C++20 constructs.
Note: requires validation on GB10 / DGX Spark hardware. Author does not have access to a coherent UMA system.
References
Same root cause fixed in nvtop: Syllo/nvtop#463
NVML unified shim for GB10: https://github.com/parallelArchitect/nvml-unified-shim
btop discussion: #1586
Note
Requires validation on GB10 / DGX Spark hardware. Author does not have access to a coherent UMA system.