From mboxrd@z Thu Jan 1 00:00:00 1970 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 B0B7570818 for ; Tue, 7 Apr 2026 14:04:19 +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=1775570659; cv=none; b=E+2fJ08Fk7uFyvUIKnepieiV73is3LhszygApwDxnQZmcKZj77Xt8FclGJ9UEwSdaH5/RmdPL4z0hFVbu7VFqVaywvcbEUCKJU944bxLVNhTwMaNslCZfvmM4e6fG2NwMLT9YXHWI6Ql00zX9HL3N6CelrjWkk4XTCutW8QbJ9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775570659; c=relaxed/simple; bh=YpiW0E2JUUnKYs4Ck/w3P0cqQOsNWSO9qCHnjdUPI6A=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aXCRpQ7IXZioWc5dfwvCEDKVVGISnYb9XsQsRJGjHIRAiflphZK8JX/nTHduuUIb+bWB7xWIPcQ2yzXrT0JglE6S5em/A6sduuiRzs6jU7wNG9B1mA4fjLuSgmyx93Bm338a+UsRTvQwG3pQT3NT+Jq1tRJKEJz7O/I7dIQ8AAE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CE4jobFy; 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="CE4jobFy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5C63C116C6; Tue, 7 Apr 2026 14:04:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775570659; bh=YpiW0E2JUUnKYs4Ck/w3P0cqQOsNWSO9qCHnjdUPI6A=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CE4jobFyUGbzBZv/mUiT335g/hHhb1W0R4g/7WnQ76y6qjJJPhlYx26qMNl2wN9L8 BB7wfn1tRlVN/e/liJWfYca8vYd+tV+c+FnYo847pJ6phnLLGELMHVZKpvuDbT//FM 7VWBSEcwSoytRIUe1TLKpbqLun/5letcOKYsCmbw70QN5dfoPPcXo+HvSsrfnzyPq6 uk4zKiSVPLekgHQ8jM8lAjvcj0fIdDS3PJ/jJIz41e7QCWBVsBMQmWPyQfQyn69MeA /5JOBORD8x0tvNT/wknBOkADcPz8GPZLWgNG7Emdm20ijB4n2gB9AgGUOdrg+38AWZ fCQSsLzI37/Qw== Date: Tue, 7 Apr 2026 07:04:17 -0700 From: Jakub Kicinski To: Eric Dumazet Cc: "David S . Miller" , Paolo Abeni , Simon Horman , Kuniyuki Iwashima , Andrew Lunn , netdev@vger.kernel.org, eric.dumazet@gmail.com Subject: Re: [PATCH net-next] net: dropreason: add SKB_DROP_REASON_{BROAD,MULTI}CAST_BACKLOG Message-ID: <20260407070417.38ace6ca@kernel.org> In-Reply-To: References: <20260403022443.3480770-1-edumazet@google.com> <20260406180254.5221a267@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 7 Apr 2026 03:09:41 -0700 Eric Dumazet wrote: > On Mon, Apr 6, 2026 at 6:02=E2=80=AFPM Jakub Kicinski w= rote: > > On Fri, 3 Apr 2026 02:24:43 +0000 Eric Dumazet wrote: =20 > > > ipvlan and macvlan use queues to process broadcast or multicast packe= ts > > > from a work queue. > > > > > > Under attack these queues can drop packets. > > > > > > Add BROADCAST_BACKLOG drop_reason for macvlan broadcast queue. > > > > > > Add MULTICAST_BACKLOG drop_reason for ipvlan multicast queue. =20 > > > > What distinction are you trying to communicate by using BROADCAST > > vs MULTICAST? Funny naming of the functions aside I believe that > > in both cases we're basically dealing with multicast traffic. > > Reading the code it seems like macvlan has some optimization where > > it delivers the frame inline if the multicast group is not very > > popular. And if it is popular it schedules a work (and calls that > > broadcast). ipvlan doesn't have the inline filter and calls the > > deliver via work multicast. > > > > tl;dr I think the drivers do the same thing just call their functions > > broadcast vs multicast. Having two drop reasons here is actively > > misleading? =20 >=20 > My intent was to differentiate ipvlan and macvlan reasons, some > deployments use both. >=20 > I can rename the reasons if you think this is better. >=20 > IPVLAN_MULTICAST_BACKLOG >=20 > MACVLAN_BROADCAST_BACKLOG Sounds better, thanks