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 6EDBDF514 for ; Fri, 14 Jul 2023 09:56:16 +0000 (UTC) Received: from mail-yb1-xb42.google.com (mail-yb1-xb42.google.com [IPv6:2607:f8b0:4864:20::b42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F5E71989; Fri, 14 Jul 2023 02:56:15 -0700 (PDT) Received: by mail-yb1-xb42.google.com with SMTP id 3f1490d57ef6-c15a5ed884dso1607291276.2; Fri, 14 Jul 2023 02:56:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1689328574; x=1691920574; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=iLc4IFOrSQMumdSS27cGww/H0solCQj99/m3cUx+za0=; b=U0+zCc7J47tgv3aokD+C9AbGUM0547IcCiSQEMzpBI+mYOOCtmzjv7TLV+15+Way2l uIapCaUXBbx/phM9GIB5BFOIQNEHzbA7jNpWh7+Q0iZmZlO65IBlPd0HnXlJWqMc85kk H5Q4LKdYKUNGqjL37XpunuGMoJ+Mtpl/BpDiZ03rfuXmWzrYel5MjIzmIiBpL+k04NA0 kIairDRA5S1vy0oVMkSwlo7M5XJ/2BC54TEVtGPKe6UNZB69tMRoq1VkITMgaXFHnnev jeNCPG4T6jWGDnPKvbonN9yBfdH9GzBYSvFo4RyjgabhCFa4S3I4hdoNRXo1mIFSILk5 15TA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689328574; x=1691920574; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iLc4IFOrSQMumdSS27cGww/H0solCQj99/m3cUx+za0=; b=CuG1wJK4rCKUeQrs4VmvNSzlLQlFVi2ZuQygDuSfZpeJW8pGKCbMpHRdVSJP8Db4oL 56zM0z16dwhz9sA1lJL0osvIUQk6jzrJUgc3UzwKdFl9ta27kfGtWBTJB3UDp9CZBDDK +Reah7AcM+F7LfkoqsTWJ2RZgKO8WBkc/NzoA16W0iH++2SJwbCu36WCFdNiRdMABnXm XYSyXxUeRUldK3kvu4nqYFOdGt/lBiQBmwNUWiqtjvDjDqAyUlAedRRdkp6dXb3Dr58v LZXtKZcMgVglCczkvX7ce3tqGJtOYEMEufR6vZTlFVPz4aHztjjVkfUf1n+lF/gTYYEv 03og== X-Gm-Message-State: ABy/qLZi4k6YPzzIMNE21fHX7+iga9kPqaweKN0mrem0do0+WlJpi+6S BCPmf+ipdMuAcRyx7PmFtghOB9t/7S/wl4aChuI= X-Google-Smtp-Source: APBJJlEP9rHYkKqqEeB1DAv7b3BU8yZcSQXF4+FqdKNDY/5pBH0h3wFr0gaoNioOqIHxzaGSE7p70VM3SMLPFrINvDs= X-Received: by 2002:a25:32d8:0:b0:ba7:7664:916b with SMTP id y207-20020a2532d8000000b00ba77664916bmr3607425yby.20.1689328574374; Fri, 14 Jul 2023 02:56:14 -0700 (PDT) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20230713112404.2022373-1-imagedong@tencent.com> <04a96ba2-6952-e6de-93a2-dc2998ce519d@infradead.org> In-Reply-To: <04a96ba2-6952-e6de-93a2-dc2998ce519d@infradead.org> From: Menglong Dong Date: Fri, 14 Jul 2023 17:56:03 +0800 Message-ID: Subject: Re: [PATCH net-next v2] net: tcp: support to probe tcp receiver OOM To: Randy Dunlap Cc: edumazet@google.com, ncardwell@google.com, 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,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 Thu, Jul 13, 2023 at 11:43=E2=80=AFPM Randy Dunlap wrote: > > > > On 7/13/23 04:24, menglong8.dong@gmail.com wrote: > > diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/net= working/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. > Thanks! I'll fix them in the next version. > -- > ~Randy