From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=DQhsNHuw; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTPS id A587E5A0271 for ; Mon, 08 Dec 2025 09:25:36 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1765182335; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pPZAO0/UiKkNeJu31enRiwinoM9xRHObB5PCF7lwzRU=; b=DQhsNHuwHAlWZDIDlkLNjkRH2E8kPtwuCWZ4nql191c62Hjx3qWWi0sVUG1SUWMVsKo0zj dNy02t3rklc92D+Bmd1MsJAKm6864e+x2FWbivXMT9y78oJGBnWb9CbkIXOf4047nk3WRk BSblVsqsFrf/MANT7x/xLXAYBgYwSSU= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-689-XFQ_zTqFP7GyVpWYql-aaA-1; Mon, 08 Dec 2025 03:25:34 -0500 X-MC-Unique: XFQ_zTqFP7GyVpWYql-aaA-1 X-Mimecast-MFC-AGG-ID: XFQ_zTqFP7GyVpWYql-aaA_1765182333 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-47921784b97so26712805e9.0 for ; Mon, 08 Dec 2025 00:25:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765182333; x=1765787133; h=content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=pPZAO0/UiKkNeJu31enRiwinoM9xRHObB5PCF7lwzRU=; b=qxftOCnL7+yhrgYw19v6+wGhjhhwmQXNp0iYLOTMzRS/HY+WLpHnW1hjWsAcCtwsWq kREc63W3Ynt/TWNFRi7w6yLHh3iCYXbRzE0dwvSjbD9FL8TuYC7nH3wJSuZFlqHOaGZc AJ+MOAWWvB+75m8dZ+UyweQqyyMrxwUchiCpFa+s9ow4S+QDwtoRPrFD2DHna1K9zYoB M7WosErs7jb2XrH5cPUPf8x4hxLmAL/eK/7ISbUMBgHEFTlv9fYRRDnJNILYfyHjv4sz JLgSfCQrMtKA9/O5jq4UYSzVUrnBfFpAPm/9cse2mTnwsHT1OAZsNjpRLBAsQIR2raze cUnw== X-Gm-Message-State: AOJu0Yx7lQohakI/CwwrvGIi3sg2kb/N5lXqysLVleOQtC9ieoPCFIiI ZnyMEDCHLk187wz2kLEMEcsOGPwUe19szXC3//AHEDihsu65rD9xghkVC6EAEijGwoQx+xZoR+Z t6wPR3LvNaXJb0BJOxgDb6EDLgIyafLXfLuqvFN19l7oXVo/Z6UQkyw== X-Gm-Gg: ASbGnctgnTYr2AVPHjguazbmw+LrtTsQIPqnPgA5nVl3cl2FkCFlGo/3cMoeT/Q6/UY eS2Frx7NwGspw1YtKV7Kqsmbr4rD+taHAgoHik/r0t/QOx9Igy/jd9uZyYaK6STcYhwNqs55wuC o0dQGg63dnY5YgA+rOnpGnGumKbR4lD/oSR2oVA+PRj+45bpWGuQUFgv0VmyrfWA6zVfQ1N2lT/ /p7bMKh8iZ81IDY0ymHoYlhdqWn1qxbm8EmYOFd0fcxOyQ4RvVBbPTlsAHO19MPIZXt/lbTPU4k C6dXIAbDVaCQMV0GI3gTPFb/PL2QNuQEyVa6Da7hUFNvIZFf1hhS9BFxNQatq1jpJhcf39J4jfm FUWU1MFeYTyEbpYaXWuKSR45RrILC+tdNZN78cg== X-Received: by 2002:a05:600c:a01:b0:477:63a4:88fe with SMTP id 5b1f17b1804b1-47939df379amr68700085e9.2.1765182332920; Mon, 08 Dec 2025 00:25:32 -0800 (PST) X-Google-Smtp-Source: AGHT+IGAjiOjSOTolIYtS+wpj8i1i+hxUoJfLwJMezzvgYpSYFwwYfIbeCsTiPa3rJyTRZqnFZdd6g== X-Received: by 2002:a05:600c:a01:b0:477:63a4:88fe with SMTP id 5b1f17b1804b1-47939df379amr68699715e9.2.1765182332410; Mon, 08 Dec 2025 00:25:32 -0800 (PST) Received: from maya.myfinge.rs (ifcgrfdd.trafficplex.cloud. [176.103.220.4]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-42f7d222484sm24489107f8f.24.2025.12.08.00.25.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Dec 2025 00:25:31 -0800 (PST) Date: Mon, 8 Dec 2025 09:25:30 +0100 From: Stefano Brivio To: Max Chernoff Subject: Re: [PATCH v3 00/10] tcp: Fix throughput issues with non-local peers Message-ID: <20251208092530.2638636a@elisabeth> In-Reply-To: References: <20251208072024.3884137-1-sbrivio@redhat.com> Organization: Red Hat X-Mailer: Claws Mail 4.2.0 (GTK 3.24.49; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Ag0ostH_rLqQNuYyo1yCv3BFrMCufjOVXmW78nDxomc_1765182333 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: NVJZC3N3UJ5F2YJEJIDSXDJR5BSF7CXA X-Message-ID-Hash: NVJZC3N3UJ5F2YJEJIDSXDJR5BSF7CXA X-MailFrom: sbrivio@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top, David Gibson X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Hi Max, On Mon, 08 Dec 2025 01:11:56 -0700 Max Chernoff wrote: > Hi Stefano, > > On Mon, 2025-12-08 at 08:20 +0100, Stefano Brivio wrote: > > With this series, I'm getting the expected (wirespeed) throughput for > > transfers between peers with varying non-local RTTs: I checked > > different guests bridged on the same machine (~500 us) and hosts with > > increasing distance using iperf3, as well as HTTP transfers only for > > some hosts I have control over (500 us and 5 ms case). > > > > With increasing RTTs, I can finally see the throughput converging to > > the available bandwidth reasonably fast: > > Thanks for the patch, but this unfortunately seems to make things worse > in my testing (with curl/https). Using my benchmarking script from the > earlier thread, with a 10MB file size and a 30s timeout: Thanks for re-testing. I actually wanted to get back to you about your sysctl values, but, in general, I don't think things can work reliably with the values you shared for tcp_notsent_lowat. Does this (upload now taking longer/timing out with 50 ms RTT) also happen without "custom" values for tcp_notsent_lowat? I tested things quite extensively in that RTT region (without custom sysctl values) and the improvement looks rather consistent to me. -- Stefano