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Re-arm trimming and setsockopt dedup were dropped: dev's RX-epoll path (epoll_register, epoll_fd_state) already issues EPOLL_CTL_MOD directly, and each accept path sets TCP_NODELAY exactly once. The fcntl pair stays: cwist_http_pool_submit_async is a public API that blocking fds reach.
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Closing: CLOCK_MONOTONIC is already vDSO-served on Linux, so COARSE saves tens of nanoseconds per poll slice, and the classic blocking pool this touches is not exercised by the benchmark harness (default async/io_uring). No measurable effect; the re-arm optimization this PR originally proposed is already covered by dev's RX-epoll path (epoll_register, 0fd8c21). |
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The classic pool's header-read loop calls clock_gettime every poll slice; CLOCK_MONOTONIC_COARSE (vDSO, ~4 ms granularity) removes that syscall against a 120 s budget.
Scope was reduced during rebase: dev's RX-epoll path (epoll_register with fd-state MOD-first hints) already trims the re-arm syscall, and no per-accept setsockopt duplication exists. Measured end-to-end delta is below noise; the win is one fewer syscall per idle poll slice.