netdev - Re: [patch net-next v3 2/2] net: core: introduce mini_Qdisc and eliminate usage of tp->q for clsact fastpath

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 1 Nov 2017 11:30:52 +0100
From:   Jiri Pirko <jiri@...nulli.us>
To:     Daniel Borkmann <daniel@...earbox.net>
Cc:     Alexei Starovoitov <alexei.starovoitov@...il.com>,
        netdev@...r.kernel.org, davem@...emloft.net, jhs@...atatu.com,
        xiyou.wangcong@...il.com, mlxsw@...lanox.com, edumazet@...gle.com,
        alexander.h.duyck@...el.com, willemb@...gle.com,
        john.fastabend@...il.com
Subject: Re: [patch net-next v3 2/2] net: core: introduce mini_Qdisc and
 eliminate usage of tp->q for clsact fastpath

Wed, Nov 01, 2017 at 11:25:02AM CET, daniel@...earbox.net wrote:
>On 11/01/2017 03:12 AM, Alexei Starovoitov wrote:
>> On Tue, Oct 31, 2017 at 04:12:22PM +0100, Jiri Pirko wrote:
>> > From: Jiri Pirko <jiri@...lanox.com>
>[...]
>> I don't think it's great, but I don't have any suggestions on
>> how to avoid it, so I'm not objecting. Just disappointed that
>> you keep adding stuff to tc and messing with sw fast path only to
>> make parity with some obscure hw feature.
>
>tc became a sink for that over time.

Block sharing is not only useful for offloads. But I understand.

>
>> If it keeps going like this we'd need to come up with some new fast
>> hook for clsbpf in ingress/egress paths. We use it for
>> every packet, so extra loads are not great.
>> I guess they should be cache hits, but will take extra cache line.
>> All of the bugs in tc logic recently are not comforting either.
>
>+1

I don't see any effect of tc changes on clsbpf ingress/egress since
clsact was introduced. Could you point it out?