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AJvYcCVkCAv9xnYNRXYYZZlhJlcV0ao6rwLGtjSZGi9aYPL8FBAsAQWJ5sL/gJcs+eE8z1uSteq4GQMA@vger.kernel.org, AJvYcCXI9C65AiGpG9BAyrd5IPp0ZIbICa5hUW7p3/uZ39o9JX6TBtVkD3N9mEsFmkVg9f9yf3o=@vger.kernel.org X-Gm-Message-State: AOJu0YzHLrV3Xziv7QlCt90ndKki1qvDXpIORagVnq5eth2qKMOpY7xs 2x0lP+8sxQKLqj81/Im4dkSmXlChEb4nj6/akwryJhZidoKbf5/6SoTmTdsqUuzW4jfWjE7lhD7 05VR5ILFDJsEGsrljbklBK5BYGpX9S+w= X-Gm-Gg: ASbGncuXEgOm92eKuheJu2a/mBzX8sjGtc7O9TIYX4shKA3xjcpOTntTQqM7/xlDu6P 6UKdN7RKAigVNPrZZSTbD1LYpmpxCDLU8n/MG6+DWsSnB5qMDq64k0yvca1M5f0Zzi0bu57qSe1 ka2X8TJoRV7HxE4UsayoigWaFZ6SIR4Uv3mnwTH1dDrno= X-Google-Smtp-Source: AGHT+IG+rpDJaUfnaV5m+nBDgXBESL6oV+9kwJ4Ca2V63lF4y+BB32avIF0+VsSEEMjVjxOeB7u0ufczbJ4TjecudkA= X-Received: by 2002:a05:6e02:1fc3:b0:3dd:d338:5c7a with SMTP id e9e14a558f8ab-3de07c53d09mr231042235ab.4.1750274706436; Wed, 18 Jun 2025 12:25:06 -0700 (PDT) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250617002236.30557-1-kerneljasonxing@gmail.com> <6852fe267553f_3471a129472@willemb.c.googlers.com.notmuch> In-Reply-To: <6852fe267553f_3471a129472@willemb.c.googlers.com.notmuch> From: Jason Xing Date: Thu, 19 Jun 2025 03:24:30 +0800 X-Gm-Features: AX0GCFuIM8VOQ4eitJGzDuyG7QBuswUwdJGS1iCEwWZafbYh0BXVZf5Mawcf9xw Message-ID: Subject: Re: [PATCH net-next 0/2] net: xsk: add two sysctl knobs To: Willem de Bruijn Cc: Stanislav Fomichev , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, bjorn@kernel.org, magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, jonathan.lemon@gmail.com, sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, bpf@vger.kernel.org, netdev@vger.kernel.org, Jason Xing Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, Jun 19, 2025 at 1:58=E2=80=AFAM Willem de Bruijn wrote: > > Jason Xing wrote: > > Hi Stanislav, > > > > On Tue, Jun 17, 2025 at 9:11=E2=80=AFAM Stanislav Fomichev wrote: > > > > > > On 06/17, Jason Xing wrote: > > > > From: Jason Xing > > > > > > > > Introduce a control method in the xsk path to let users have the ch= ance > > > > to tune it manually. > > > > > > Can you expand more on why the defaults don't work for you? > > > > We use a user-level tcp stack with xsk to transmit packets that have > > higher priorities than other normal kernel tcp flows. It turns out > > that enlarging the number can minimize times of triggering sendto > > sysctl, which contributes to faster transmission. it's very easy to > > hit the upper bound (namely, 32) if you log the return value of > > sendto. I mentioned a bit about this in the second patch, saying that > > we can have a similar knob already appearing in the qdisc layer. > > Furthermore, exposing important parameters can help applications > > complete their AI/auto-tuning to judge which one is the best fit in > > their production workload. That is also one of the promising > > tendencies :) > > It would be informative to include this in the commit. Sure, I will add more in V3. > > Or more broadly: suggestions for when and how to pick good settings > for these new tunables. I'm not sure what is a good setting in general. But I will try to describe how I use it and what my understanding of it is in the commit message. Thanks, Jason