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[176.103.220.4]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-438bd4b99dfsm127890385e9.26.2025.01.27.02.32.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jan 2025 02:32:15 -0800 (PST) Date: Mon, 27 Jan 2025 11:32:14 +0100 From: Stefano Brivio To: Jason Xing Subject: Re: [net,v2] tcp: correct handling of extreme memory squeeze Message-ID: <20250127113214.294bcafb@elisabeth> In-Reply-To: References: <20250117214035.2414668-1-jmaloy@redhat.com> <20250127110121.1f53b27d@elisabeth> Organization: Red Hat X-Mailer: Claws Mail 4.2.0 (GTK 3.24.41; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 1SZauOWgPclOYT54kXRyvZiT0y-JnL5X-n2Nv_QUgkc_1737973937 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: KMOVLX52V5MDU3QBGKXU7TMZYZKUXSYQ X-Message-ID-Hash: KMOVLX52V5MDU3QBGKXU7TMZYZKUXSYQ 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: Jon Maloy , Eric Dumazet , Neal Cardwell , netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, passt-dev@passt.top, lvivier@redhat.com, dgibson@redhat.com, eric.dumazet@gmail.com, Menglong Dong 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: On Mon, 27 Jan 2025 18:17:28 +0800 Jason Xing wrote: > I'm not that sure if it's a bug belonging to the Linux kernel. It is, because for at least 20-25 years (before that it's a bit hard to understand from history) a non-zero window would be announced, as obviously expected, once there's again space in the receive window. > The other side not sending a window probe causes this issue...? It doesn't cause this issue, but it triggers it. > The other part of me says we cannot break the user's behaviour. This sounds quite relevant, yes. -- Stefano