Binyang Li 9ec26fa4d1 Reset GPU tokens before reuse (#795) ...

Fixes a token-reuse bug in `TokenPool` that's independent of MNNVL.

## Bug

`TokenPool` hands out 8-byte device-memory slots used as
device-semaphore counters. The deleter only cleared the bitmap — the
underlying GPU memory was left as-is. When a token was freed and later
re-allocated, the new semaphore inherited the previous counter value
instead of starting at 0, breaking subsequent `signal()/wait()` math.

## Fix

* Add a synchronous `gpuMemset` host helper (mirrors `gpuMemcpy` /
`gpuMemcpyAsync`).
* Zero the slot inside the `TokenPool` deleter so recycled tokens hand
out a clean counter. The very-first allocation is already zeroed by
`gpuCallocPhysical` (`src/core/gpu_utils.cc:227-228`), so first-time
tokens are also clean — the deleter only has to handle the recycle case.

## Notes

* Public wrapper is named `mscclpp::gpuMemset` (not `mscclpp::memset`)
for symmetry with `gpuMemcpy` and to avoid shadowing `std::memset` in
TUs that pull the namespace in.
* Zeroing happens on release rather than acquire so the cost is paid in
the typically less perf-sensitive teardown path.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

2026-05-04 15:11:47 -07:00

..

mscclpp

Reset GPU tokens before reuse (#795)

2026-05-04 15:11:47 -07:00

CMakeLists.txt

Torch integration (#692)

2026-01-21 20:32:24 -08:00