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Date: Fri, 13 Mar 2026 00:10:23 +0100
From: Florian Westphal <fw@strlen.de>
To: Prasanna Panchamukhi <panchamukhi@arista.com>
Cc: netfilter-devel@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Simon Horman <horms@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
	Shuah Khan <skhan@linuxfoundation.org>,
	Pablo Neira Ayuso <pablo@netfilter.org>, Phil Sutter <phil@nwl.cc>,
	netdev@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, coreteam@netfilter.org
Subject: Re: [PATCH net-next] netfilter: conntrack: expose
 gc_scan_interval_max via sysctl
Message-ID: <abNH3xxxAU7U4zz5@strlen.de>
References: <20260311194058.13860-1-panchamukhi@arista.com>
 <abKzWIhVz_SeiSOa@strlen.de>
 <CACqWiXD2_O32K4NhmNBZrAUG7U9-N93LTFjJHG6Tq=4vuafNuA@mail.gmail.com>
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Prasanna Panchamukhi <panchamukhi@arista.com> wrote:
> Our primary goal is to cap the maximum time taken by the GC to clean
> up expired entries. We rely on user-space notifications to clean up
> these entries from the hardware, so ensuring a predictable upper bound
> is important for our use case.

Sure, but why can't we try to give a better default behavior?

while true; conntrack -L >/dev/null;done

basically does what you want already (but in a dumb way).

> Regarding the adaptive strategy, we are using this sysctl to address
> environments where the current average-based calculation delays the
> cleanup of short-lived entries.

Yes, and I did propose to adapt the existing strategy to provide more
timely notifications.