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 C79151EA74 for ; Thu, 13 Jul 2023 15:43:17 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18DCF2680; Thu, 13 Jul 2023 08:43:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=e1RschMAietqo4yrW4fae/Y/YBT6qlJyR4H15nx9b/c=; b=j+Mu6xLXRTrrXKeT6HECd8Ud04 XKOaZ9pu9coE1LMrRTG2GcvkI/IbXHqweQ6930xoT+KufQV8LMto4yh74B3+Ef03ZTIV8/vOA2Gnw IKaPSyDnh/vMH9OdwrRJ5yBbONMxeeGdxBnaXlKuZGgQZaNoQHw6B6y43IknlVytCnAALiCbPLqB0 2RWjhUsQdJF4cIQfvCEWpEgzxhG8hVjOVQqBIjVY7FAbW0smvrVAZbu0nJhexL/Z1So+u9u5z6nl9 8NfBvA2IojHJjXevR+bPzh4IX8WOXd/pF/ZDZw3nteZ9TfDZ43IfYkfGzYnwADsBmv++TDYfl4uhc 2QKB5qZw==; Received: from [2601:1c2:980:9ec0::2764] by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qJyT1-003o2A-0C; Thu, 13 Jul 2023 15:42:55 +0000 Message-ID: <04a96ba2-6952-e6de-93a2-dc2998ce519d@infradead.org> Date: Thu, 13 Jul 2023 08:42:53 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH net-next v2] net: tcp: support to probe tcp receiver OOM Content-Language: en-US To: menglong8.dong@gmail.com, edumazet@google.com, ncardwell@google.com Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, corbet@lwn.net, dsahern@kernel.org, kuniyu@amazon.com, morleyd@google.com, imagedong@tencent.com, mfreemon@cloudflare.com, mubashirq@google.com, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230713112404.2022373-1-imagedong@tencent.com> From: Randy Dunlap In-Reply-To: <20230713112404.2022373-1-imagedong@tencent.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 7/13/23 04:24, menglong8.dong@gmail.com wrote: > diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst > index 4a010a7cde7f..3de2dce74037 100644 > --- a/Documentation/networking/ip-sysctl.rst > +++ b/Documentation/networking/ip-sysctl.rst > @@ -694,6 +694,20 @@ tcp_retries2 - INTEGER > RFC 1122 recommends at least 100 seconds for the timeout, > which corresponds to a value of at least 8. > > +tcp_oom_retries - INTEGER > + RTO retransmissions count of the receiver is recognised as OOM. > + Given a value N, a hypothetical TCP connection will enter probe > + state if N times RTO retransmissions performed and every > + retransmission gets a pure ack, who doesn't contain SACK block. ACK > + > + The default value is 0, which means disable the OOM detection. > + If disabled, skb will be dropped directly, without sending an > + ACK, when rmem schedule fails. The function is valid only if sack SACK > + is enabled. > + > + 3 is the suggested value to enable this function. Do't make it Don't > + greater than tcp_retries2. -- ~Randy