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Date: Sat, 7 Feb 2026 11:39:10 +0100
From: Florian Westphal <fw@strlen.de>
To: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, Steffen Klassert <steffen.klassert@secunet.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Simon Horman <horms@kernel.org>
Subject: Re: [PATCH net-next] xfrm: reduce struct sec_path size
Message-ID: <aYcWTvF7SNm1NojP@strlen.de>
References: <83846bd2e3fa08899bd0162e41bfadfec95e82ef.1770398071.git.pabeni@redhat.com>
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In-Reply-To: <83846bd2e3fa08899bd0162e41bfadfec95e82ef.1770398071.git.pabeni@redhat.com>

Paolo Abeni <pabeni@redhat.com> wrote:
> The mentioned struct has an hole and uses unnecessary wide type to
> store MAC length and indexes of very small arrays.
> 
> It's also embedded into the skb_extensions, and the latter, due
> to recent CAN changes, may exceeds the 192 bytes mark (3 cachelines
> on x86_64 arch) on some reasonable configurations.
> 
> Reordering and the sec_path fields, shrinking xfrm_offload.orig_mac_len
> to 16 bits and xfrm_offload.{len,olen,verified_cnt} to u8, we can save
> 16 bytes and keep skb_extensions size under control.

Reviewed-by: Florian Westphal <fw@strlen.de>