From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 6611F3CB37 for ; Mon, 5 Aug 2019 14:21:21 -0400 (EDT) Received: by mail-io1-xd29.google.com with SMTP id s7so169153140iob.11 for ; Mon, 05 Aug 2019 11:21:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=I0HEADfQjrsTAutmEk0oBhojGvuYCNIsGRkpYGCMVBQ=; b=H6upCVJsdLUgeRZBjCDqo8dkA9IVzHzP1g9uZ2Vmp5MVboFbLPgJ8rSDQk+Z491nqR BYs1j978FsZUFMWjHMhdxSnzAco0zkO4d/Fz8rZ20WLgIpUKLH4yCTemnDXjpWZJ1iXk cObI05CuEoJMudt8KAdNL2ru+pIK7muCvl6y0I4sr/KsinOFEng1WRG8XjIFKsQ4RElL TM5vl94k70bJ441rmZ2DJXQZ9BSKU1GiZAokV4QiyT524A0HGkbLeVHueWdFxAdWpw5G YUUgic4dkMAKcXQEefZJNSkZbGy3EDg2aShHMuZxA0uW+TJPSRW/UIIe6+Xqxhax27Ka 8xnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=I0HEADfQjrsTAutmEk0oBhojGvuYCNIsGRkpYGCMVBQ=; b=Yj5qhgQ2z8jvbHA5Zf0QrqCnphBcxA/lw9jDUagqnXqvZnt+2O6FKMcwUL4GNdpS3g qPnVkpJBZVxkv4NTqO3m0G9MRMCCsp3Gky9mlASakSj5sn+XdLQrER7mVIYRQXTIap8e nKUxvPDC2whqggnG9QkjPjuySjvU86lxVIfwV4V//1WaiPHIw8GTazF9pMn0X8KdqaPf wD/UI/yM6x2ujtBIpx8WRMHPAdBK6tNBufa9jCMFKdBgea8tt2W0b4xTMmOjBK4wor74 rnwzKOtpdVrJ7P7MZYcd0hVYX35vCg4VdPPK/pGNXnogvIHk39VleFUh6kega3ozZmqu 8u2g== X-Gm-Message-State: APjAAAWn7QAV7v8cOKIzaq16FRIzyTJFRD71NAuyOF/VoFOYXT7z+hvd iv5ea78xGxYTJUZ9Itu+YBIitAV57kzgiyH4B7FQoukK X-Google-Smtp-Source: APXvYqyHVQBJtHPeFlfoPG4uQm3xN6PvzSCjQiz+YOYFsXhsy5MxAPgybLy6HSrcla8yqT4W65JKavKtIUKZr8q65sQ= X-Received: by 2002:a6b:dd17:: with SMTP id f23mr1378362ioc.213.1565029280557; Mon, 05 Aug 2019 11:21:20 -0700 (PDT) MIME-Version: 1.0 From: Dave Taht Date: Mon, 5 Aug 2019 11:21:09 -0700 Message-ID: To: ECN-Sane Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: [Ecn-sane] net-next dctcp mod question X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Aug 2019 18:21:21 -0000 The SCE tree had two key looking modifications to it that seem to have been superceded by net-next. My reading of the remaining differences seem to be resolved in the state machine where setting the last portion of the SCE patch appears to do a decrease on multiple losses. ? Can I not forward port these? --- a/net/ipv4/tcp_dctcp.c +++ b/net/ipv4/tcp_dctcp.c @@ -110,7 +110,7 @@ static u32 dctcp_ssthresh(struct sock *sk) static void dctcp_update_alpha(struct sock *sk, u32 flags) { - const struct tcp_sock *tp =3D tcp_sk(sk); + struct tcp_sock *tp =3D tcp_sk(sk); struct dctcp *ca =3D inet_csk_ca(sk); /* Expired RTT */ @@ -138,6 +138,7 @@ static void dctcp_update_alpha(struct sock *sk, u32 fla= gs) */ WRITE_ONCE(ca->dctcp_alpha, alpha); dctcp_reset(tp, ca); + tp->snd_cwnd =3D dctcp_ssthresh(sk); } } @@ -147,6 +148,7 @@ static void dctcp_react_to_loss(struct sock *sk) struct tcp_sock *tp =3D tcp_sk(sk); ca->loss_cwnd =3D tp->snd_cwnd; + tp->snd_cwnd =3D max(tp->snd_cwnd >> 1U, 2U); tp->snd_ssthresh =3D max(tp->snd_cwnd >> 1U, 2U); } --=20 Dave T=C3=A4ht CTO, TekLibre, LLC http://www.teklibre.com Tel: 1-831-205-9740