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From:   Dave Taht <dave.taht@gmail.com>
Date:   Mon, 9 May 2022 00:53:28 -0700
Message-ID: <CAA93jw4dFxwWCrhv98wwbPvM+UrAQKYRNbbSVp3UCp1zOnsD5w@mail.gmail.com>
Subject: Re: [PATCH RFC v1 net-next 1/4] net: Introduce Qdisc backpressure infrastructure
To:     Peilin Ye <yepeilin.cs@gmail.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        Peilin Ye <peilin.ye@bytedance.com>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Cong Wang <cong.wang@bytedance.com>
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I am very pleased to see this work.

However,  my "vision" such as it was, and as misguided as it might be,
was to implement a facility similar to tcp_notsent_lowat for udp
packets, tracking the progress of the udp packet through the kernel,
and supplying backpressure and providing better information about
where when and why the packet was dropped in the stack back to the
application.

I've been really impressed by the DROP_REASON work and had had no clue
prior to seeing all that instrumentation, where else packets might be
dropped in the kernel.

I'd be interested to see what happens with sch_cake.

--=20
FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_code=
l/
Dave T=C3=A4ht CEO, TekLibre, LLC