From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72B9D5665 for ; Wed, 11 Oct 2023 02:15:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20230601.gappssmtp.com header.i=@networkplumber-org.20230601.gappssmtp.com header.b="FOfsVGOy" Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC82B92 for ; Tue, 10 Oct 2023 19:15:45 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id d2e1a72fcca58-690d8c05784so4946376b3a.2 for ; Tue, 10 Oct 2023 19:15:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1696990545; x=1697595345; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=iECfGCpMxcwrOgs+tK/rI+0nJVijEyGocy239dFmGxw=; b=FOfsVGOyen6210JUZf6RoaLh4INK/xXaj5V0rJaAm02pRP6SfoPF9LhjkfH4KNaDMG y70mn9l7Gkk4LzK/WjeIxKgETTYRLt+IkOZIx9DsYj2pnEI9uuGj2NLLaZy03qIqcOI+ F/4SZI7ImhLbJOgfLVVVaK6lixakD+4+zwQz5EoYeHLhAO/6vW+2fqD26xsiQzMZU4PK 3udg3Usvl/HMo0shMJPW2fDDzuS3x5tc/g8P4VbwjvxsInHMDcrKJ3UFyzom6GWCYO3a aptnO4MiS+NmtpHpUm/alr/jyjiD2QoTIerc/pEKVlqxcI7cl5yEkC5yJK16+AmdXaHQ htyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696990545; x=1697595345; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iECfGCpMxcwrOgs+tK/rI+0nJVijEyGocy239dFmGxw=; b=f2VJmV42zJKNc6AaOwlnvmGHB0OpX9uY8nR2vxTlJ4Qulx67nj9V/Iqbm61GyIhLSC zjxn3e8dR4+g4DoqkoR5imOhotyG3VrnnX/PYiSVVgI6NYEMLDGsMhOvRhRV6Wd/Gff3 TBjIhcy4PLun/N9oJobd5VcdUMdpHPjeCW7BHlwKsF/KGGWCRXT5TtKbPSHL2D0eCo5I moA+O6BFoWqmfEBlgZZJ1hvsO9udXQtZvp6sCo1qcW9wOZ5CPYeOwxo5kfKO6aXJl0iR mv9f6HcCTCeYVdrqyNt6+SPqTi8RjIotDBS1+EoI/DiolFBtQquHVzrtNbAWmzCDiL04 8Ukw== X-Gm-Message-State: AOJu0Ywp+19+rLfed80PhUVjbCtQQTs9m7cdXfwSxyCY35gpb8knJIpe 3i8y3COkZQXYk3NuBUfb2pd39w== X-Google-Smtp-Source: AGHT+IHm97r7d3gBuXSWs26WG7XXCFQuF+p7rtRB/I0tH02ivL0P9H4FSQmQz0CNE9SoZk9IC3noqQ== X-Received: by 2002:a05:6a00:3a16:b0:693:4143:5145 with SMTP id fj22-20020a056a003a1600b0069341435145mr20705305pfb.31.1696990545282; Tue, 10 Oct 2023 19:15:45 -0700 (PDT) Received: from hermes.local (204-195-126-68.wavecable.com. [204.195.126.68]) by smtp.gmail.com with ESMTPSA id u5-20020aa78385000000b0068c90e1ec84sm8959795pfm.167.2023.10.10.19.15.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Oct 2023 19:15:44 -0700 (PDT) Date: Tue, 10 Oct 2023 19:15:42 -0700 From: Stephen Hemminger To: Haiyang Zhang Cc: Yuchung Cheng , "linux-hyperv@vger.kernel.org" , "netdev@vger.kernel.org" , KY Srinivasan , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "corbet@lwn.net" , "dsahern@kernel.org" , "ncardwell@google.com" , "kuniyu@amazon.com" , "morleyd@google.com" , "mfreemon@cloudflare.com" , "mubashirq@google.com" , "linux-doc@vger.kernel.org" , "weiwan@google.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH net-next,v2] tcp: Set pingpong threshold via sysctl Message-ID: <20231010191542.3688fe24@hermes.local> In-Reply-To: References: <1696965810-8315-1-git-send-email-haiyangz@microsoft.com> <20231010151404.3f7faa87@hermes.local> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Tue, 10 Oct 2023 22:59:49 +0000 Haiyang Zhang wrote: > > > If this an application specific optimization, it should be in a socket option > > > rather than system wide via sysctl. > > Initially I had a similar comment but later decided a sysctl could > > still be useful if > > 1) the entire host (e.g. virtual machine) is dedicated to that application > > 2) that application is difficult to change > > Yes, the customer actually wants a global setting. But as suggested by Neal, > I changed it to be per-namespace to match other TCP tunables. Like congestion control choice, it could be both a sysctl and a socket option. The reason is that delayed ack is already controlled by socket options.