From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f53.google.com (mail-lf1-f53.google.com [209.85.167.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B4FD1F4C84 for ; Tue, 3 Jun 2025 07:27:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748935625; cv=none; b=oHtimZBtta716HDt+ujlMKeyNcqdtHfmEAoPNtSK7jXp93Oy72ti2VuBohe2okW5yzp6LizeMBPnaQv9ylzcwjijVkIZzs5RplIBwwHB4gUVJ58prT6IioOXzL62t8pg3oOzoDxLDZW7PR6pBMxjCpxMMcALwz8KOblMMgKSWvU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748935625; c=relaxed/simple; bh=Xoq+mK9zf0H8LenpVm3kOakbdazUu+08ZQfDA4mYe84=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=bSxxWKfAebJvgArqs4uMgqqiuqrjBM8pn0bSHaow1pFu0mWV4rb28QiQunWWhTqnyKntRO24BFwHYaWzBH/nCohqwQR6KWrNv1xTB/2m/7Zi6PRvQuT22Nn2ghmCE4hFupNr+Ls9KDOsvcz2PIGMMutY1cFHnSv+tROSkzaJOPM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=deepl.com; spf=pass smtp.mailfrom=deepl.com; dkim=pass (2048-bit key) header.d=deepl.com header.i=@deepl.com header.b=VXsIkSk6; arc=none smtp.client-ip=209.85.167.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=deepl.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=deepl.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=deepl.com header.i=@deepl.com header.b="VXsIkSk6" Received: by mail-lf1-f53.google.com with SMTP id 2adb3069b0e04-55342bca34eso3063024e87.2 for ; Tue, 03 Jun 2025 00:27:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=deepl.com; s=google; t=1748935621; x=1749540421; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=Xoq+mK9zf0H8LenpVm3kOakbdazUu+08ZQfDA4mYe84=; b=VXsIkSk6XB23DTAkiwYWsQCnnRWrWE84H9v7uB2THELWqwCAEN+ek1k/SN0L+zFoAN Ben0C8tgFyepytROeaYDGCuDXPmT6Zg+SCXK8nTPZLTmD+YI8zpUw01a9xOa7lHVKnbs OxKuAPcO4S/drwnnbJsInKi7ALifevKe9jgan/seOLWj0ReTXN9RmooyJZmPWCJTAAng RKEP6eJw4Jy7ygN9nptnra0iWP3zTFHBr7WOUVQaFOywe0GgDjyjW9yUSMCEg5FDC9HM 9H4iUyP8ws0oezs0jpMrPnyJOYQ5lpSJL+wC+u4puC9yHLIkkR+IlHyCglDTSGRTslLx ffIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748935621; x=1749540421; h=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=Xoq+mK9zf0H8LenpVm3kOakbdazUu+08ZQfDA4mYe84=; b=kttSvQam463cZ2RZI8H24eHWmet2/EkqLwPiEb0JcOq4g326KBa1V9uqIKd/yYhGRL q2k0KhzT+DM7wHcw/e0bfZ7bBlnjuVxBg/lx9KHvZt9nTbc8pb8tTGKG+kWPMXjEHe+E /3ab1IWTAO3WlBjSIn5Hqs5RYWNjmnS+/K/imK6DOk78IMwO+aUvM6dg2oYc6dSS5h+t nd0relyQWwm5UPRaMxzWQXCU5PdPiAsnXKJZmk04xMh1XB0EVPBretnU6xVA6EefNFpG bjCKgzGwOZlN8xLXbB7gqChNrSUmiMekGtTP80tnsCqYhMLgoTPGOo/hMbziTy9SosPz upcw== X-Gm-Message-State: AOJu0YwSsu377CqeZq4wLRHCWddlK6A9lhdA/t2bNef5urT2zjSWSgtS NE7RZAGv1mfJzlMz4ibT5irN16XemQVkJOIAzSBx6qK9EU1r6BXjVbPnysRc3Xy5sX4zEQlEThI 5oT/fbsbYosC7KaSGLumZBDx4hwaJoDlnEPALH1E2Bw== X-Gm-Gg: ASbGncsSKqJF62uePj+ToWgF2UPq6I8Pz0L3ciU8D+Fd1/26hTO03g6JleqYtZWUNN4 DB2iz9DljnDxRAYSncN0pRLyXk76xb33uwMASgKzIrehsTUR99U5ifYGgqB4e3bKI4Xj4r4UVGg X0vG1o6D0uToVZdGPU4fJx7MCO8pCX7/6D99u3TOjB6j2HWMa0pJjhwlp9uAJmul1BeFycr1VV8 slo3A== X-Google-Smtp-Source: AGHT+IHnOxMpT17DyGanETutgx7NXTaV3I4W7jMEWt2JfcisYDMim6rkuN1QzE/OAIBe/2KU63V7kSYKFaZ1T/mZE6k= X-Received: by 2002:a05:6512:4615:b0:553:5166:5a5f with SMTP id 2adb3069b0e04-55351665bb3mr911040e87.53.1748935621291; Tue, 03 Jun 2025 00:27:01 -0700 (PDT) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: In-Reply-To: From: Simon Campion Date: Tue, 3 Jun 2025 09:26:50 +0200 X-Gm-Features: AX0GCFv1Rv1rI74thQJj53yrO_PV_noWK-5GOkjRjS_d2jJ6BjN9rMxxjFLAqfE Message-ID: Subject: Re: Re: [EXT] Re: tcp: socket stuck with zero receive window after SACK To: Neal Cardwell Cc: netdev@vger.kernel.org, Eric Dumazet , Yuchung Cheng , Kevin Yang , Jon Maloy Content-Type: text/plain; charset="UTF-8" > I agree it will take a while to gather more confidence that the issue > is gone for your workload with net.ipv4.tcp_shrink_window=0. To confirm, it's been over a week since we set net.ipv4.tcp_shrink_window=0, and so far we haven't seen an issue with TCP connections being stuck with a zero window and an empty recv-q. So, it looks like the problem is either entirely gone or occurs much less frequently with net.ipv4.tcp_shrink_window=0. We also attempted to reproduce the issue with a program that sends data over a TCP connection but leaves out the first N bytes. Unfortunately, we haven't been able to reproduce the issue so far, even with net.ipv4.tcp_shrink_window=1 and with a system under memory pressure. Simon