Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 18 Jul 2023 11:29:40 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     David Ahern <dsahern@kernel.org>
Cc:     Jason Gunthorpe <jgg@ziepe.ca>,
        Mina Almasry <almasrymina@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
        netdev@vger.kernel.org, linux-arch@vger.kernel.org,
        linux-kselftest@vger.kernel.org,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Christian =?UTF-8?B?S8O2bmln?= <christian.koenig@amd.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
        Shuah Khan <shuah@kernel.org>
Subject: Re: [RFC PATCH 00/10] Device Memory TCP
Message-ID: <20230718112940.2c126677@kernel.org>
In-Reply-To: <35f3ec37-11fe-19c8-9d6f-ae5a789843cb@kernel.org>
References: <20230710223304.1174642-1-almasrymina@google.com>
        <12393cd2-4b09-4956-fff0-93ef3929ee37@kernel.org>
        <CAHS8izNPTwtk+zN7XYt-+ycpT+47LMcRrYXYh=suTXCZQ6-rVQ@mail.gmail.com>
        <ZLbUpdNYvyvkD27P@ziepe.ca>
        <20230718111508.6f0b9a83@kernel.org>
        <35f3ec37-11fe-19c8-9d6f-ae5a789843cb@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Tue, 18 Jul 2023 12:20:59 -0600 David Ahern wrote:
> On 7/18/23 12:15 PM, Jakub Kicinski wrote:
> > On Tue, 18 Jul 2023 15:06:29 -0300 Jason Gunthorpe wrote:  
> >> netlink feels like a weird API choice for that, in particular it would
> >> be really wrong to somehow bind the lifecycle of a netlink object to a
> >> process.  
> > 
> > Netlink is the right API, life cycle of objects can be easily tied to
> > a netlink socket.  
> 
> That is an untuitive connection -- memory references, h/w queues, flow
> steering should be tied to the datapath socket, not a control plane socket.

There's one RSS context for may datapath sockets. Plus a lot of the
APIs already exist, and it's more of a question of packaging them up 
at the user space level. For things which do not have an API, however,
netlink, please.