From patchwork Thu Jun 1 19:09:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Khalid Elmously X-Patchwork-Id: 1789309 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=WBSTNxuK; dkim-atps=neutral Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4QXG1r4qs2z20Wc for ; Fri, 2 Jun 2023 05:10:56 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1q4nh7-0006NW-AS; Thu, 01 Jun 2023 19:10:45 +0000 Received: from smtp-relay-internal-1.internal ([10.131.114.114] helo=smtp-relay-internal-1.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1q4nh5-0006Me-Bw for kernel-team@lists.ubuntu.com; Thu, 01 Jun 2023 19:10:43 +0000 Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-1.canonical.com (Postfix) with ESMTPS id 117403F4DF for ; Thu, 1 Jun 2023 19:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1685646642; bh=JuANSbi8ncnz5UNY6oLNxTaUL2x8khqbP15v1DuuvKk=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=WBSTNxuKqp3+eHu71kCxFTOq1tAFyRs7k37I96ybUEf6WybCXCmGKHoMXiXcA3tAO 4BapLXEfyrOttJWaU8gJEmPkAFlxOmcdFC/wEI6aEZ92OZ6worwuFyQ1lVXw5/09HZ nYvNVDrqLUtNOyGsifGYty0ZvTvw2spf9l5K5wfsFRo6hIwUFZB0RmPt2iBWsVGhAM Kb5O8w0jgVYoV+IceNM3S4m9xQovogCsweMtjPIjv+sX3kvfzIbEdLMM7NIBOgtcm6 ltFvfB0L1/K4jptoYygiLUcpiXPpUBFcBOibmWQ1OVNv9wRp+luRU5V4gzeTywUuj+ NUrGZWIyTE5Dw== Received: by mail-qk1-f200.google.com with SMTP id af79cd13be357-75b1c0a6b2fso136463185a.0 for ; Thu, 01 Jun 2023 12:10:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685646641; x=1688238641; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JuANSbi8ncnz5UNY6oLNxTaUL2x8khqbP15v1DuuvKk=; b=PIhMq3PowXjo4cGvomWL517lp7Q+1B+/xPk5VGMQ/yq+ijUB76ZoHGYON0qDJkp7dZ PqxMxKkhXTqMLdveZPb4bTZ0tV3HDi/pNXK2oWT1P0NW4CXVQUBe7/qQ8h7lPDh3ZWea gBW26u7oIedLaQnJOKtRIvEcPf2cDjM0V/iKZE0aSqgaVcZCBvbUSVlxBwO0/bJkH7X3 tDRRmeZydvWuhNHGEk23ue8eOorjrMpygQBPLCcC/sV/n5S6XJrkwLH0F1g4d/Eyho3f 00iXYHd/Uz4wgPKFuzChotN4dvpOnBZOHnDZch0z2JrsAVOMZLjy+Osg0n4aUCxMt7dR 07mQ== X-Gm-Message-State: AC+VfDyt/R9tobUzykOQD3MpuSReaFK3ma3VBjVJI12vUy1L/hECkW+k jtrBevhbBxHrhXiuZ4F6kXltoNepCqU/xF0xfhjyiepfVwDLilMAyKSai5fnBISSElYfopxPvVV 69mcSCJhPBmjM0be1Bj3NQM2W1aMcHxtCxgRCOgTNn9M5i8NuKNH6 X-Received: by 2002:a05:620a:284e:b0:75b:23a1:8e5b with SMTP id h14-20020a05620a284e00b0075b23a18e5bmr10738347qkp.44.1685646641014; Thu, 01 Jun 2023 12:10:41 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5p94uAtJX7KAJwNp7g+Pb09gt/z/KwrPNqeu9jQScH7gJnBnDiJl26XyMYq0LSgXr9PAaAXA== X-Received: by 2002:a05:620a:284e:b0:75b:23a1:8e5b with SMTP id h14-20020a05620a284e00b0075b23a18e5bmr10738332qkp.44.1685646640723; Thu, 01 Jun 2023 12:10:40 -0700 (PDT) Received: from k2.fuzzbuzz.org ([38.147.253.170]) by smtp.gmail.com with ESMTPSA id p8-20020a05620a15e800b0075c97468f57sm5549947qkm.82.2023.06.01.12.10.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Jun 2023 12:10:40 -0700 (PDT) From: Khalid Elmously To: kernel-team@lists.ubuntu.com Subject: [SRU][j/gke][f/gke][PATCH 0/1] Make new NFS cache behaviour opt-in Date: Thu, 1 Jun 2023 15:09:36 -0400 Message-Id: <20230601190938.1040712-1-khalid.elmously@canonical.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" BugLink: https://bugs.launchpad.net/bugs/2022098 The fix to LP #2003053 has caused massively increased NFS server access in some use-cases, which caused severe performance degradation to the point of being unusable. The solution to this issue, at least temporarily and at least for linux-gke, is to make the new behaviour optional using the "nfs_fasc=1" module parameter. Without this parameter specified, (or specified as =0) will keep the old behaviour. Thanks Thadeu for the feedback and the original inspiration for this fix. Testing: - Used a slightly modified version of this patch (which simply logs whether the new or the old behaviour is taking effect) on an NFS client to confirm that 'modprobe nfs' and 'modprobe nfs nfs_fasc=0' maintain the old behaviour, and that 'modprobe nfs nfs_fasc=1' implements the new cache behaviour. Regresion potential: - Regression potential is considered low considering the scope of the change and is limited to NFS only. Khalid Elmously (1): UBUNTU: SAUCE: Make NFS file-access stale cache behaviour opt-in fs/nfs/dir.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) Acked-by: Dimitri John Ledkov Acked-by: Tim Gardner Acked-by: Andrei Gherzan