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From: Florian Westphal <fw@strlen.de>
To: scott.k.mitch1@gmail.com
Cc: netfilter-devel@vger.kernel.org, pablo@netfilter.org
Subject: Re: [PATCH v8] netfilter: nfnetlink_queue: optimize verdict lookup with hash table
Date: Sat, 24 Jan 2026 17:49:38 +0100	[thread overview]
Message-ID: <aXT4IvpC0wY0bor9@strlen.de> (raw)
In-Reply-To: <20260123220930.43860-1-scott.k.mitch1@gmail.com>

scott.k.mitch1@gmail.com <scott.k.mitch1@gmail.com> wrote:
> From: Scott Mitchell <scott.k.mitch1@gmail.com>
> 
> The current implementation uses a linear list to find queued packets by
> ID when processing verdicts from userspace. With large queue depths and
> out-of-order verdicting, this O(n) lookup becomes a significant
> bottleneck, causing userspace verdict processing to dominate CPU time.
> 
> Replace the linear search with a hash table for O(1) average-case
> packet lookup by ID. A global rhashtable spanning all network
> namespaces attributes hash bucket memory to kernel but is subject to
> fixed upper bound.
> 
> Signed-off-by: Scott Mitchell <scott.k.mitch1@gmail.com>

Thanks for addressing all my comments, I don't see anything else
that would block this from getting merged.

      reply	other threads:[~2026-01-24 16:49 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-23 22:09 [PATCH v8] netfilter: nfnetlink_queue: optimize verdict lookup with hash table scott.k.mitch1
2026-01-24 16:49 ` Florian Westphal [this message]

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