From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 01FD72EC563 for ; Thu, 6 Nov 2025 10:57:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762426639; cv=none; b=TpMcT50NzHfunocuwYVcaDZnv8oc2/4bSdV851dD0AzwIPZhAgXnDgKSXdHHH3frr2HhaOLfNX/Ab6evYSk0PKhgO+dJ7kEcl0v3tpvMO5BO1eKh6WJg2XZUeg4T03AXT/+uR4rPNz5j/ocXxJtdv3WAgAe3vY7QcRyrL8T9Pxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762426639; c=relaxed/simple; bh=9invMdERfhYKNnXg74LQAFbXckBFXN636tVMG/vPhmk=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=CfhOJC76IE5x7xY4fHQJBDrV8BBnlcH+OtZAV7jLKbYGAEWQxKAG8esuDr8rt82wavyepdePWA4yNmZis0wM3X/o1dqrgFvyTSq7r+F0MivHjPmftJfzvsA+LYtlWRN6tr5nHa84fDzR9H16dJpZeEXeO2TGJ6G76u6glebS3x4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=U2ZNeaJ+; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=grDVQcA4; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U2ZNeaJ+"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="grDVQcA4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762426637; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kDAN1HMJoQQtQ55I20Dw66H+vj6obQIAmVodeSEuemo=; b=U2ZNeaJ+RaHnqIZimKjMdZYFt5ev1UuR2dNIGYuv5v23yoVdI9U0tiZu9X0yP26V2CIO19 efUvIgOUa3ENQKeiObGq+lAyY57StiflbVh3fq9RnWfrO8cLpwuKMSQk4CiqtmaHivnyu+ GRlxgftD4GdDf03aVHob1xL7hhYVQ34= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-529-BCUzUq_CO_CMHVxBDFaLOw-1; Thu, 06 Nov 2025 05:57:15 -0500 X-MC-Unique: BCUzUq_CO_CMHVxBDFaLOw-1 X-Mimecast-MFC-AGG-ID: BCUzUq_CO_CMHVxBDFaLOw_1762426633 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-429ce8ac89bso723790f8f.1 for ; Thu, 06 Nov 2025 02:57:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1762426632; x=1763031432; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id:from :to:cc:subject:date:message-id:reply-to; bh=kDAN1HMJoQQtQ55I20Dw66H+vj6obQIAmVodeSEuemo=; b=grDVQcA4IIFdE0So8kwToiBQbNlLPgaIdDPiSxX+C/FuB++X/USEZOPz538ddu4iNT Mx3ebMoFz2lRn7MwLwXTUuMCHAt5XM7Ytnqr/Zu4kHRU9+4cgSpAIyXWXl3CVkXog45d BwKJucxcUPFMcjsl3o2eliFK4MjWROxAhSQRlQjV58OvFAHMwk8VA41EDUKctDdLYj++ uhODnFr1vzcRSSG0GwusM9vO250X/D4dXLaPhVLjkEHw6A80FmaeqPQcPOT/2xGkFxuc QiCGAWA7ljTZNUhxTHi1t2+CMf/DRs/ayYeucX0R4dZqTenDsfpLK4E+G3+/pT8NnFMq 0GqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762426632; x=1763031432; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=kDAN1HMJoQQtQ55I20Dw66H+vj6obQIAmVodeSEuemo=; b=gZXtJlGOHJP16oQAo2GCqJvxMn75AtCAekVdI1+1iHZh1BTpm65RbVzD1zlH9/3Jt6 izROV4VBLPg5XPduq10OuAePWKh1hSEbQX1nUgH+TxrqpOkkXT/t/yRvt/TTlJ6RBlvy sBzio/q9Bn2RSfiRWQ6VfGwNu2jpIMhJnzS+EOkZIo9JHF1DEYlOeAZGAuuKYoRawRys YQlMO0aSvWLg82/u2MiaZPGxLF0yKdhfplHZft3LR+H8l/oou0R4OG5bCKogPY2YWeHb FVAvMTl5Pd3kWRvu6u/SCWcbMc2ILc/70LjYdP8Wn4YSqLH4s/cOebZ7gyLGmGNO5MZV PBvw== X-Forwarded-Encrypted: i=1; AJvYcCV8dew+4YFZ7AXj4dz5te/ziV+MaejBT3tv2haLePHQbrcXtSr/Gwfjyph0gjRW/8gHyerWQxkb4wI=@vger.kernel.org X-Gm-Message-State: AOJu0Ywii8xzp/Fu7uU0zsJD86hKNmrWxqaDbH53zBkSGdSvDwNVjEqO NCaPOER3t96fJ1DSG28AkgeL4ldECuudxYTwYp8Fe6rbv2lCClk2rbr+UntreJaNWZ6KNNL9yki 5Mw0B6tWTw0mhTybbGQfpMXOM63DVvm2EC6TpHmWqrq58zdDEcw9I5O7PD2NFUClHpfRPyA== X-Gm-Gg: ASbGnctN/fI72vue1BfGNwt2f9LEZh4JX2lsxKQgwUcBmXVDEBmWbUbdg1AJcku79RZ L3nyx/L+zE9n5ArjPSFlS8XgCoLjznnZpIR44oy1XPEj4q4DarZS/KXO434pQc7mL0NzS+nAM8v Ff3PgbEsZiaLCpgTBSyQNjXMZK79D8FzwsuVxz6XAslZuAmk3P03Ned9S5Sb5xP3UhjLqAcllxS 4okLCkvedSasbhKm5BJt2X9BhU4TcivticQajjIy3yHlH+gntILPDd4rWPLvHGPv0G0AM6TpgGv S+M9+/P1vQKO5w2bFknFrZuIEWf8nxZGn/EcwSXap/abyqIU1AZxTMkGSdCyktTNPB6PUY+EDt3 +Nw== X-Received: by 2002:a05:6000:2811:b0:429:edfa:309e with SMTP id ffacd0b85a97d-429edfa32admr1087648f8f.20.1762426632517; Thu, 06 Nov 2025 02:57:12 -0800 (PST) X-Google-Smtp-Source: AGHT+IGuo4Zz37FAjgeqMkvLjK2yjkrDZq4CtR/TEtSlcvQWi/2zCplPBisLlN9/n2avyBib7PRi5Q== X-Received: by 2002:a05:6000:2811:b0:429:edfa:309e with SMTP id ffacd0b85a97d-429edfa32admr1087626f8f.20.1762426632119; Thu, 06 Nov 2025 02:57:12 -0800 (PST) Received: from [192.168.88.32] ([212.105.155.83]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-429eb49baf4sm4127409f8f.33.2025.11.06.02.57.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Nov 2025 02:57:11 -0800 (PST) Message-ID: <2f38933e-f24e-4a14-a906-0d06bc194a21@redhat.com> Date: Thu, 6 Nov 2025 11:57:09 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 net-next 01/14] tcp: try to avoid safer when ACKs are thinned To: chia-yu.chang@nokia-bell-labs.com, edumazet@google.com, parav@nvidia.com, linux-doc@vger.kernel.org, corbet@lwn.net, horms@kernel.org, dsahern@kernel.org, kuniyu@google.com, bpf@vger.kernel.org, netdev@vger.kernel.org, dave.taht@gmail.com, jhs@mojatatu.com, kuba@kernel.org, stephen@networkplumber.org, xiyou.wangcong@gmail.com, jiri@resnulli.us, davem@davemloft.net, andrew+netdev@lunn.ch, donald.hunter@gmail.com, ast@fiberby.net, liuhangbin@gmail.com, shuah@kernel.org, linux-kselftest@vger.kernel.org, ij@kernel.org, ncardwell@google.com, koen.de_schepper@nokia-bell-labs.com, g.white@cablelabs.com, ingemar.s.johansson@ericsson.com, mirja.kuehlewind@ericsson.com, cheshire@apple.com, rs.ietf@gmx.at, Jason_Livingood@comcast.com, vidhi_goel@apple.com References: <20251030143435.13003-1-chia-yu.chang@nokia-bell-labs.com> <20251030143435.13003-2-chia-yu.chang@nokia-bell-labs.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20251030143435.13003-2-chia-yu.chang@nokia-bell-labs.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 10/30/25 3:34 PM, chia-yu.chang@nokia-bell-labs.com wrote: > From: Ilpo Järvinen > > Add newly acked pkts EWMA. When ACK thinning occurs, select > between safer and unsafe cep delta in AccECN processing based > on it. If the packets ACKed per ACK tends to be large, don't > conservatively assume ACE field overflow. > > This patch uses the existing 2-byte holes in the rx group for new > u16 variables withtout creating more holes. Below are the pahole > outcomes before and after this patch: > > [BEFORE THIS PATCH] > struct tcp_sock { > [...] > u32 delivered_ecn_bytes[3]; /* 2744 12 */ > /* XXX 4 bytes hole, try to pack */ > > [...] > __cacheline_group_end__tcp_sock_write_rx[0]; /* 2816 0 */ > > [...] > /* size: 3264, cachelines: 51, members: 177 */ > } > > [AFTER THIS PATCH] > struct tcp_sock { > [...] > u32 delivered_ecn_bytes[3]; /* 2744 12 */ > u16 pkts_acked_ewma; /* 2756 2 */ > /* XXX 2 bytes hole, try to pack */ > > [...] > __cacheline_group_end__tcp_sock_write_rx[0]; /* 2816 0 */ > > [...] > /* size: 3264, cachelines: 51, members: 178 */ > } > > Signed-off-by: Ilpo Järvinen > Co-developed-by: Chia-Yu Chang > Signed-off-by: Chia-Yu Chang Acked-by: Paolo Abeni