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Date: Sat, 22 Aug 2026 13:44:01 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: netdev@vger.kernel.org, Jiri Pirko <jiri@resnulli.us>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Paolo Abeni
 <pabeni@redhat.com>, Simon Horman <horms@kernel.org>, John Fastabend
 <john.fastabend@gmail.com>, stable@vger.kernel.org, vega@nebusec.ai,
 "Victor Nogueira" <victor@mojatatu.com>
Subject: Re: [PATCH net 1/2] net/sched: pfifo_fast: cap ring size and
 account to memcg
Message-ID: <20260822134401.6545e4eb@kernel.org>
In-Reply-To: <20260820095742.68511-1-jhs@mojatatu.com>
References: <20260820095742.68511-1-jhs@mojatatu.com>
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On Thu, 20 Aug 2026 05:57:41 -0400 Jamal Hadi Salim wrote:
> +	if (qlen > 65535) {
> +		pr_warn_ratelimited("pfifo_fast: capping ring size %u to 65535 for dev %s\n",
> +				    qlen, qdisc_dev(qdisc)->name);
> +		qlen = 65535;
> +	}

Why not a hard cap? We do that all over the place, once in a release we
pick a value too small and someone quickly sends us a fix up to bump
the number. No problem.