FEXCore: Use WritePriorityMutex for Code Invalidation Mutex #5408
Merged
lioncash merged 2 commits intoFEX-Emu:mainfrom Apr 6, 2026
Merged
FEXCore: Use WritePriorityMutex for Code Invalidation Mutex #5408lioncash merged 2 commits intoFEX-Emu:mainfrom
lioncash merged 2 commits intoFEX-Emu:mainfrom
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…e includes This will be used in a moment.
The previous `ForkableSharedMutex` using `std::shared_mutex` was showing up as significant CPU time on arm64ec. In particular it was showing up upwards of 700ms/S of CPU time for read-contented workloads at only ~2700 locks per second. The libc++ implementation for arm64ec must be particularly gnarly for this to be so slow. With this swapped over, it's now only spending around 56ms/S on the contended shared lock, but at ~8000 locks per second. So a significant uplift.
lioncash
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Apr 6, 2026
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The previous
ForkableSharedMutexusingstd::shared_mutexwas showingup as significant CPU time on arm64ec. In particular it was showing up
upwards of 700ms/S of CPU time for read-contented workloads at only
~2700 locks per second. The libc++ implementation for arm64ec must be
particularly gnarly for this to be so slow.
With this swapped over, it's now only spending around 56ms/S on the
contended shared lock, but at ~8000 locks per second. So a significant
uplift.