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 BE8A4286AF; Mon, 16 Oct 2023 16:50:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="Vfl84jOT" Received: from smtp-fw-9105.amazon.com (smtp-fw-9105.amazon.com [207.171.188.204]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 425D62D4B; Mon, 16 Oct 2023 09:49:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1697474999; x=1729010999; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=t3l+YeDhb2m5yEYQ+Uz0O6KM2oDfAiG0VxShhKQFeOM=; b=Vfl84jOTUS+Bn5apYMifaGYH7RruxXqGFjeQsvFA1mD5x64jBkdHTRnl dJxPpE0db+VcOhIuptnOoKv2GmA4cVsc3WE70Mn/JGnCvuK7WPgti8mwD 2N6k2E0k4mVxR1e98JRdaOCOHE2JxzJuXjcDMsm3cJkr5AVgvJrbXj01s w=; X-IronPort-AV: E=Sophos;i="6.03,229,1694736000"; d="scan'208";a="678687985" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1d-m6i4x-f05d30a1.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-9105.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2023 16:49:51 +0000 Received: from smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev (iad7-ws-svc-p70-lb3-vlan3.iad.amazon.com [10.32.235.38]) by email-inbound-relay-iad-1d-m6i4x-f05d30a1.us-east-1.amazon.com (Postfix) with ESMTPS id 866DE805BA; Mon, 16 Oct 2023 16:49:45 +0000 (UTC) Received: from EX19MTAUWA001.ant.amazon.com [10.0.7.35:4719] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.31.209:2525] with esmtp (Farcaster) id 0c6df8e9-0c7b-461f-aaca-88f72a41d973; Mon, 16 Oct 2023 16:49:44 +0000 (UTC) X-Farcaster-Flow-ID: 0c6df8e9-0c7b-461f-aaca-88f72a41d973 Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWA001.ant.amazon.com (10.250.64.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Mon, 16 Oct 2023 16:49:40 +0000 Received: from 88665a182662.ant.amazon.com (10.187.171.29) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Mon, 16 Oct 2023 16:49:36 +0000 From: Kuniyuki Iwashima To: CC: , , , , , , , , , , , , , , , , , Subject: Re: [PATCH net-next,v3] tcp: Set pingpong threshold via sysctl Date: Mon, 16 Oct 2023 09:49:27 -0700 Message-ID: <20231016164927.30126-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <1697056244-21888-1-git-send-email-haiyangz@microsoft.com> References: <1697056244-21888-1-git-send-email-haiyangz@microsoft.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.187.171.29] X-ClientProxiedBy: EX19D031UWC004.ant.amazon.com (10.13.139.246) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: Bulk X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_NONE,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net From: Haiyang Zhang Date: Wed, 11 Oct 2023 13:30:44 -0700 > TCP pingpong threshold is 1 by default. But some applications, like SQL DB > may prefer a higher pingpong threshold to activate delayed acks in quick > ack mode for better performance. > > The pingpong threshold and related code were changed to 3 in the year > 2019 in: > commit 4a41f453bedf ("tcp: change pingpong threshold to 3") > And reverted to 1 in the year 2022 in: > commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"") > > There is no single value that fits all applications. > Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for > optimal performance based on the application needs. > > Signed-off-by: Haiyang Zhang Reviewed-by: Kuniyuki Iwashima Thanks!