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Date: Thu, 13 Jul 2023 09:57:47 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Yan Zhai <yan@cloudflare.com>
Cc: Ivan Babrou <ivan@cloudflare.com>, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, kernel-team@cloudflare.com, Eric Dumazet
 <edumazet@google.com>, "David S. Miller" <davem@davemloft.net>, Paolo Abeni
 <pabeni@redhat.com>, Steven Rostedt <rostedt@goodmis.org>, Masami Hiramatsu
 <mhiramat@kernel.org>, David Ahern <dsahern@kernel.org>
Subject: Re: [RFC PATCH net-next] tcp: add a tracepoint for
 tcp_listen_queue_drop
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On Wed, 12 Jul 2023 21:43:32 -0500 Yan Zhai wrote:
> Those are not unnecessary calls, e.g. a lot of those kfree_skb come
> from iptables drops, tcp validation, ttl expires, etc. On a moderately
> loaded server, it is called at a rate of ~10k/sec, which isn't
> terribly awful given that we absorb millions of attack packets at each
> data center. We used to have many consume skb noises at this trace
> point with older versions of kernels, but those have gone ever since
> the better separation between consume and drop.

I was hoping you can break them down by category.

Specifically what I'm wondering is whether we should also have 
a separation between policy / "firewall drops" and error / exception
drops. Within the skb drop reason codes, I mean.