From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <xiyou.wangcong@gmail.com>
Subject: Re: [patch net-next v2 00/10] net: sched: allow qdiscs to share
 filter block instances
Date: Wed, 15 Nov 2017 15:12:47 -0800
Message-ID: <CAM_iQpXpXx6XguOS8com0Dq-mYn_w3-+mLNBdEco++VF3erC2A@mail.gmail.com>
References: <20171112155604.24061-1-jiri@resnulli.us>
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Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
        David Miller <davem@davemloft.net>,
        Jamal Hadi Salim <jhs@mojatatu.com>, mlxsw@mellanox.com,
        andrew@lunn.ch,
        Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jakub Kicinski <jakub.kicinski@netronome.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Simon Horman <simon.horman@netronome.com>,
        Pieter Jansen van Vuuren
        <pieter.jansenvanvuuren@netronome.com>, john.hurley@netronome.com
To: Jiri Pirko <jiri@resnulli.us>
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On Sun, Nov 12, 2017 at 7:55 AM, Jiri Pirko <jiri@resnulli.us> wrote:
> From: Jiri Pirko <jiri@mellanox.com>
>
> Currently the filters added to qdiscs are independent. So for example if you
> have 2 netdevices and you create ingress qdisc on both and you want to add
> identical filter rules both, you need to add them twice. This patchset
> makes this easier and mainly saves resources allowing to share all filters
> within a qdisc - I call it a "filter block". Also this helps to save
> resources when we do offload to hw for example to expensive TCAM.
>
> So back to the example. First, we create 2 qdiscs. Both will share
> block number 22. "22" is just an identification. If we don't pass any
> block number, a new one will be generated by kernel:

Should not block 0 by used by default if not specified by user?
Why a new one?


>
> $ tc qdisc add dev ens7 ingress block 22
>                                 ^^^^^^^^
> $ tc qdisc add dev ens8 ingress block 22
>                                 ^^^^^^^^
>
> Now if we list the qdiscs, we will see the block index in the output:
>
> $ tc qdisc
> qdisc ingress ffff: dev ens7 parent ffff:fff1 block 22
> qdisc ingress ffff: dev ens8 parent ffff:fff1 block 22
>
> Now we can add filter to any of qdiscs sharing the same block:
>
> $ tc filter add dev ens7 ingress protocol ip pref 25 flower dst_ip 192.168.0.0/16 action drop
>

So you don't need to specify block 22 for this filter?
Because there is only one block???


>
> We will see the same output if we list filters for ens7 and ens8, including stats:
>
> $ tc -s filter show dev ens7 ingress
> filter protocol ip pref 25 flower chain 0
> filter protocol ip pref 25 flower chain 0 handle 0x1
>   eth_type ipv4
>   dst_ip 192.168.0.0/16
>   not_in_hw
>         action order 1: gact action drop
>          random type none pass val 0
>          index 1 ref 1 bind 1 installed 39 sec used 2 sec
>         Action statistics:
>         Sent 3108 bytes 37 pkt (dropped 37, overlimits 0 requeues 0)
>         backlog 0b 0p requeues 0


Don't see which block it belongs to here.