WIP: Reducing cache choerency traffic under contention for spinlock #147
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Use the code from [1] to implement the spinlock based on std::atomic<bool> instead of std::atomic_flag. While the former is not necessarily lock-free, it is on the majority of platforms. A static assert is added to catch this on platforms that don't have this - we could potentially use the older implementation on those instead then. WIP because I don't have a good scientific benchmark for this yet. I tested it in our realworld application, and it seems to have slightly reduced the load of the spinlock, but not in a really large way... See also: efficient#146 [1]: https://rigtorp.se/spinlock/
BurningEnlightenment
suggested changes
Jun 28, 2022
| while (lock_.load(std::memory_order_relaxed)) { | ||
| // Issue X86 PAUSE or ARM YIELD instruction to reduce contention | ||
| // between hyper-threads | ||
| __builtin_ia32_pause(); |
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This intrinsic is not implemented by MSVC
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Use the code from 1 to implement the spinlock based on
std::atomic instead of std::atomic_flag. While the former
is not necessarily lock-free, it is on the majority of platforms.
A static assert is added to catch this on platforms that don't
have this - we could potentially use the older implementation on
those instead then.
WIP because I don't have a good scientific benchmark for this yet.
I tested it in our realworld application, and it seems to have
slightly reduced the load of the spinlock, but not in a really large
way...
See also: #146