From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <toke@toke.dk>
Received: from mail.toke.dk (mail.toke.dk [45.145.95.4])
 (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by lists.bufferbloat.net (Postfix) with ESMTPS id B56043CB38
 for <cake@lists.bufferbloat.net>; Wed,  4 Aug 2021 15:29:19 -0400 (EDT)
From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023;
 t=1628105358; bh=ss851UZ09rGyCKXq1cs4p/HhsDTz60pt6jH7j9f10bo=;
 h=From:To:Cc:Subject:In-Reply-To:References:Date:From;
 b=EGtfUO0OKmvrx9iFoafNwwzBO/LvMMkk/g7iTl5ttHzbvKzVSBxdPGQ4ykwGrBNRn
 PaastyN39nDog5ghRtr4UZR5KAgiSiQQd/1yJxEw22zxMkXQp0xlAlUnnqzsVRoxM7
 asZWSEb7mG+yC5E1NegR3LcmZxfLsKjvkpJGzjVGTyN9Jl43lN4F9dJyIrQKFVcDTl
 84GwP0ySPJxmwb4aRwc79r2GnmErbsHc6YWuCaQa4SBwHJSe8b7vC2LC1trZQr4kkZ
 aWfsd+htIhhqxUhw7gITFax7yps0aw6TdZon99dxcwQ8hp8FweqtQiGPX2Rjhrd43G
 3zMOyXwKKDGNg==
To: Jonathan Morton <chromatix99@gmail.com>
Cc: Pete Heist <pete@heistp.net>, Cake List <cake@lists.bufferbloat.net>
In-Reply-To: <CAJq5cE0zdmfOqC+SSNHpb4JEZfXTKQh1EbzxoWLvwkkr27QO=Q@mail.gmail.com>
References: <ae9f4679222f4eb3daa0e092446cb56da2fb85f6.camel@heistp.net>
 <3ebc0a3ccdcfa67a48c5ad764ce3389782633fef.camel@heistp.net>
 <87r1f95und.fsf@toke.dk>
 <CAJq5cE0zdmfOqC+SSNHpb4JEZfXTKQh1EbzxoWLvwkkr27QO=Q@mail.gmail.com>
Date: Wed, 04 Aug 2021 21:29:16 +0200
X-Clacks-Overhead: GNU Terry Pratchett
Message-ID: <87o8ad57qr.fsf@toke.dk>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Subject: Re: [Cake] cake srchost/dsthost stopped working?
X-BeenThere: cake@lists.bufferbloat.net
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: Cake - FQ_codel the next generation <cake.lists.bufferbloat.net>
List-Unsubscribe: <https://lists.bufferbloat.net/options/cake>,
 <mailto:cake-request@lists.bufferbloat.net?subject=unsubscribe>
List-Archive: <https://lists.bufferbloat.net/pipermail/cake>
List-Post: <mailto:cake@lists.bufferbloat.net>
List-Help: <mailto:cake-request@lists.bufferbloat.net?subject=help>
List-Subscribe: <https://lists.bufferbloat.net/listinfo/cake>,
 <mailto:cake-request@lists.bufferbloat.net?subject=subscribe>
X-List-Received-Date: Wed, 04 Aug 2021 19:29:19 -0000

Jonathan Morton <chromatix99@gmail.com> writes:

> On Wed, 4 Aug 2021 at 14:14, Toke H=C3=B8iland-J=C3=B8rgensen via Cake
> <cake@lists.bufferbloat.net> wrote:
>>
>> Pete Heist <pete@heistp.net> writes:
>>
>> > One more tip, reverting this commit seems to fix it:
>> >
>> > https://github.com/torvalds/linux/commit/b0c19ed6088ab41dd2a727b60594b=
7297c15d6ce
>>
>> Ah, I think I see what the problem is; could you please try the patch
>> below?
>>
>> -Toke
>>
>> diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
>> index 951542843cab..a83c4d4326da 100644
>> --- a/net/sched/sch_cake.c
>> +++ b/net/sched/sch_cake.c
>> @@ -720,7 +720,7 @@ static u32 cake_hash(struct cake_tin_data *q, const =
struct sk_buff *skb,
>>  skip_hash:
>>         if (flow_override)
>>                 flow_hash =3D flow_override - 1;
>> -       else if (use_skbhash)
>> +       else if (use_skbhash && flow_mode & CAKE_FLOW_FLOWS)
>>                 flow_hash =3D skb->hash;
>>         if (host_override) {
>>                 dsthost_hash =3D host_override - 1;
>
> Good catch - I was going to have to wade in and remind myself how this
> lump of code worked.  But shouldn't the masking operation be in
> brackets, to make the precedence explicit?

Well, seeing as I introduced the bug, I think it's only fair that I fix
it as well ;)

I don't mind adding parenthesis; can do so when submitting a patch,
after Pete confirms that this fixes the issue...

-Toke