docs(audits): io_uring bgid u16 namespace exhaustion bound (#2044)#3894
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Document that buffer-group ids are u16 in io_uring (max 65 535 per ring), audit current `BufferRing` lifecycle (kernel reclaims via `IORING_UNREGISTER_PBUF_RING` on drop, but no in-process allocator owns the namespace), sketch the long-running daemon worst case, and propose a hard-capped slab allocator with telemetry and a typed exhaustion error before #1936 / #1937 wire PBUF_RING through the per-session ring.
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May 18, 2026
…3894) Document that buffer-group ids are u16 in io_uring (max 65 535 per ring), audit current `BufferRing` lifecycle (kernel reclaims via `IORING_UNREGISTER_PBUF_RING` on drop, but no in-process allocator owns the namespace), sketch the long-running daemon worst case, and propose a hard-capped slab allocator with telemetry and a typed exhaustion error before #1936 / #1937 wire PBUF_RING through the per-session ring.
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Summary
bgidu16 namespace ceiling (65 535 ids per ring) and locate every in-tree allocation site incrates/fast_io/src/io_uring/buffer_ring.rs.BufferRingdrop semantics: kernel reclaims viaIORING_UNREGISTER_PBUF_RING, but no in-process allocator owns the id space, so a future per-session factory could exhaust or wraparound-collide.Arc-tracked drop reuse, 50 % warn telemetry, and a typed exhaustion error before Fix clippy warning in sparse executor test #1936 / Deduplicate PATHEXT extensions when resolving fallbacks #1937 wire PBUF_RING through the per-session ring.Test plan