From: Stanislav Fomichev <sdf.kernel@gmail.com>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
Neal Cardwell <ncardwell@google.com>,
Kuniyuki Iwashima <kuniyu@google.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net-next] tcp: change bpf_skops_hdr_opt_len() signature
Date: Mon, 1 Jun 2026 08:41:08 -0700 [thread overview]
Message-ID: <ah2oCeCbMbYZeJys@devvm7509.cco0.facebook.com> (raw)
In-Reply-To: <20260601093819.469626-1-edumazet@google.com>
On 06/01, Eric Dumazet wrote:
> Some compilers do not inline bpf_skops_hdr_opt_len() from
> tcp_established_options(), forcing an expensive stack canary
> when CONFIG_STACKPROTECTOR_STRONG=y.
>
> Change bpf_skops_hdr_opt_len() to return @remaining by value
> to remove this stack canary from TCP fast path.
>
> $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
> add/remove: 0/0 grow/shrink: 1/1 up/down: 10/-59 (-49)
> Function old new delta
> bpf_skops_hdr_opt_len 297 307 +10
> tcp_established_options 574 515 -59
> Total: Before=31456795, After=31456746, chg -0.00%
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
next prev parent reply other threads:[~2026-06-01 15:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-01 9:38 [PATCH net-next] tcp: change bpf_skops_hdr_opt_len() signature Eric Dumazet
2026-06-01 15:41 ` Stanislav Fomichev [this message]
2026-06-01 18:22 ` Kuniyuki Iwashima
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