Date: Sun, 26 Jul 2026 01:01:12 +0000 From: Kevin Bowling <kbowling@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: b6b379b94781 - main - em(4): document adaptive interrupt moderation Message-ID: <6a655c58.31bc0.232cf28f@gitrepo.freebsd.org>
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The branch main has been updated by kbowling: URL: https://cgit.FreeBSD.org/src/commit/?id=b6b379b94781da5d4328f6f57273fbe7bd9dc687 commit b6b379b94781da5d4328f6f57273fbe7bd9dc687 Author: Kevin Bowling <kbowling@FreeBSD.org> AuthorDate: 2026-07-25 22:09:48 +0000 Commit: Kevin Bowling <kbowling@FreeBSD.org> CommitDate: 2026-07-26 01:00:02 +0000 em(4): document adaptive interrupt moderation Describe the disabled, adaptive, and low-latency settings and their interrupt-rate tradeoffs. MFC after: 1 week --- share/man/man4/em.4 | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/share/man/man4/em.4 b/share/man/man4/em.4 index 0e9c08560545..4835d41320b2 100644 --- a/share/man/man4/em.4 +++ b/share/man/man4/em.4 @@ -272,6 +272,20 @@ interrupt is generated. .It Va hw.em.max_interrupt_rate Maximum interrupts per second. The default value is 8000. +This is the rate used when adaptive interrupt moderation is disabled, and +the fallback when it has no usable measurement. +.It Va hw.em.enable_aim +Adaptive interrupt moderation. +The interrupt rate is derived from the average size of the packets seen +since the previous interrupt, so that bulk traffic is coalesced while small +packet traffic keeps its latency. +A value of 0 disables it and pins the rate to +.Va hw.em.max_interrupt_rate , +1 selects the normal range, and 2 selects the low-latency range. +The default value is 1. +Setting 2 raises the interrupt rate substantially on small packet workloads +and is rarely a win; prefer the default unless latency has been measured to +matter more than the additional interrupt load. .It Va hw.em.rx_process_limit Maximum number of received packets to process at a time, -1 means unlimited. The default value is 100.home | help
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