Subject: Re: [PATCH net-next] netfilter: conntrack: expose gc_scan_interval_max via sysctl

From: Florian Westphal <[email-masked]>
Date: Fri, 13 Mar 2026 00:10:23 +0100

Prasanna Panchamukhi <[email-masked]> 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.