From nobody Mon Jun 15 13:41:56 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 574BE86329; Fri, 10 Apr 2026 14:43:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775832238; cv=none; b=s/T973y8ylpCSzuKUTTEPt0ueK/2tqZuN9qzIKL5asWX6zbm0N4lA7HhBKiGPAPGakVeYbFiJ+WLt7PrbiBbOy6YlNiDQQAnzozjk/O7eFL3Tr1YtirPPhWQBOe/WZoA65UKqpApgdDM9uHNw8ifl8+uUVnnVXQJBuC0UNbkTiE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775832238; c=relaxed/simple; bh=Voqoe/SBjfC00sZXFStUwTcAzHx4Q+do243mfexnCt4=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=ghs4QBYFdIEjAf87BTdoYBAzWokyDcY8nFWcrhqJxfxp81fN7RPvRDNecOJOSYB/Siw/9NCACPfEIRzFZe377LisTAUwJ/Od61unVa0QlDpu1v+jgCTeMTxERknvExpmGAcpXaIv3mfeX8Y88ExUqVoEKBM+V1htBz0VidKfDjY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lNSq9jQf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lNSq9jQf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 901D0C2BC87; Fri, 10 Apr 2026 14:43:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775832238; bh=Voqoe/SBjfC00sZXFStUwTcAzHx4Q+do243mfexnCt4=; h=Date:From:To:Cc:Subject:From; b=lNSq9jQfVP4xrdNEqT6Hayhxn9fHQEXK2NOHhYr82UaBYsUbyygPxuOL8bKNnJ7+A jpccOgLCgJFVlH53fGgsRpleJmTA2kJ2BenxUfUVSPcK7iZK6pfzV2DcUPxsU9fkOL 6yCfWTKr/XkQ46K2G8Spq7TGmeroVNmHW7jjkVrhV7Otwgp8pop37nWLxFcFdJGemn Adcwgmy8WA2YsmdyTEi4T4+t8MiXy1V0XmdLcQMuUked9HIX5p/aWmR8U/JN32HBVo fN+i7fxEVaVWrj1Mux+Og1J2MxpqvokR56URQ4ztFD3mM1JIuG/ZY70ltVSJQsVMEH 3H9mmaBVXcDpw== Date: Fri, 10 Apr 2026 16:43:54 +0200 From: Helge Deller To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "David S. Miller" , David Ahern Cc: linux-parisc@vger.kernel.org Subject: [PATCH] net: Optimize flush calculation in inet_gro_receive() Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" For the calculation of the flush variable, use the get_unaligned_xxx() help= ers to access only relevant bits of the IP header. Note: Since I don't know the network details, I'm not sure if "& ~IP_DF" (& ~0x4000) is correct, or if "& IP_OFFSET" (& 0x1FFF) should be used inste= ad (which I believe would be more correct). Instead of possibly breaking thing= s I left it as is, but maybe some expert can check? Signed-off-by: Helge Deller diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index c7731e300a44..58cad2687c2c 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1479,7 +1479,7 @@ struct sk_buff *inet_gro_receive(struct list_head *he= ad, struct sk_buff *skb) struct sk_buff *p; unsigned int hlen; unsigned int off; - int flush =3D 1; + u16 flush =3D 1; int proto; =20 off =3D skb_gro_offset(skb); @@ -1504,7 +1504,8 @@ struct sk_buff *inet_gro_receive(struct list_head *he= ad, struct sk_buff *skb) goto out; =20 NAPI_GRO_CB(skb)->proto =3D proto; - flush =3D (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (ntohl(*(__b= e32 *)&iph->id) & ~IP_DF)); + flush =3D (get_unaligned_be16(&iph->tot_len) ^ skb_gro_len(skb)) | + (get_unaligned_be16(&iph->frag_off) & ~IP_DF); =20 list_for_each_entry(p, head, list) { struct iphdr *iph2;