[{"id":1769157,"web_url":"http://patchwork.ozlabs.org/comment/1769157/","msgid":"<9bd88ea5-1abf-633e-5573-2e13667a3841@canonical.com>","list_archive_url":null,"date":"2017-09-15T12:41:12","subject":"APPLIED Z: [SRU][Zesty][PATCH 0/1][v2]UBUNTU: SAUCE: Revert \"vhost:\n\tcache used event for better performance\"","submitter":{"id":2898,"url":"http://patchwork.ozlabs.org/api/people/2898/","name":"Stefan Bader","email":"stefan.bader@canonical.com"},"content":"On 01.09.2017 18:23, Joseph Salisbury wrote:\n> BugLink: http://bugs.launchpad.net/bugs/1711251\n> \n> == SRU Justification ==\n> A vhost performance patch was introduced in the 4.10 kernel upstream, and \n> is currently included in the Zesty 4.10 kernel:\n> \n> commit 809ecb9bca6a9424ccd392d67e368160f8b76c92\n> Author: Jason Wang \n> Date: Mon Dec 12 14:46:49 2016 +0800\n> \n> vhost: cache used event for better performance\n> \n> However IBM recently hit a functional issue linked to this patch which \n> would cause random guests to lose their network connection under stress. \n> This is not architecture specific and more likely to be hit with high \n> network stress (i.e. lots of uperf instances).\n> \n> The patch author has now reverted this patch upstream:\n> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/vhost?id=8d65843c44269c21e95c98090d9bb4848d473853\n> \n> Commit 809ecb9bca6a is reverted in mainline by commit 8d65843c44. However, commit 8d65843c44 is not a clean cherry pick\n> into Zesty, but a strait revert is clean. This is because of a context diff in \n> vhost_notify(vhost_get_user was changed to vhose_get_avail by f88949138 in v4.11-rc1). \n> \n> == Fix ==\n> Revert of upstream commit 809ecb9bca6a9424ccd392d67e368160f8b76c92.\n> \n> == Test Case ==\n> A test kernel was built with this revert and tested by the original bug reporter.\n> The bug reporter states the test kernel resolved the bug.\n> \n> \n> Joseph Salisbury (1):\n> Revert \"vhost: cache used event for better performance\"\n> \n> drivers/vhost/vhost.c | 28 ++++++----------------------\n> drivers/vhost/vhost.h | 3 ---\n> 2 files changed, 6 insertions(+), 25 deletions(-)\n> \nApplied v2 (with additional references and sob) to zesty master-next","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com\n\t(client-ip=91.189.94.19; helo=huckleberry.canonical.com;\n\tenvelope-from=kernel-team-bounces@lists.ubuntu.com;\n\treceiver=)","Received":["from huckleberry.canonical.com (huckleberry.canonical.com\n\t[91.189.94.19])\n\tby ozlabs.org (Postfix) with ESMTP id 3xtw4Z59Jpz9s7C;\n\tFri, 15 Sep 2017 22:41:18 +1000 (AEST)","from localhost ([127.0.0.1] helo=huckleberry.canonical.com)\n\tby huckleberry.canonical.com with esmtp (Exim 4.86_2)\n\t(envelope-from )\n\tid 1dspvm-0004iu-Lw; Fri, 15 Sep 2017 12:41:14 +0000","from youngberry.canonical.com ([91.189.89.112])\n\tby huckleberry.canonical.com with esmtps\n\t(TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128)\n\t(Exim 4.86_2) (envelope-from )\n\tid 1dspvl-0004iK-5T\n\tfor kernel-team@lists.ubuntu.com; Fri, 15 Sep 2017 12:41:13 +0000","from 1.general.smb.uk.vpn ([10.172.193.28])\n\tby youngberry.canonical.com with esmtpsa\n\t(TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16)\n\t(Exim 4.76) (envelope-from )\n\tid 1dspvk-0002cF-TW\n\tfor kernel-team@lists.ubuntu.com; Fri, 15 Sep 2017 12:41:12 +0000"],"Subject":"APPLIED Z: [SRU][Zesty][PATCH 0/1][v2]UBUNTU: SAUCE: Revert \"vhost:\n\tcache used event for better performance\"","To":"kernel-team@lists.ubuntu.com","References":"","From":"Stefan Bader ","Message-ID":"<9bd88ea5-1abf-633e-5573-2e13667a3841@canonical.com>","Date":"Fri, 15 Sep 2017 14:41:12 +0200","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101\n\tThunderbird/52.2.1","MIME-Version":"1.0","In-Reply-To":"","X-BeenThere":"kernel-team@lists.ubuntu.com","X-Mailman-Version":"2.1.20","Precedence":"list","List-Id":"Kernel team discussions ","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"multipart/mixed;\n\tboundary=\"===============8138356787686492008==\"","Errors-To":"kernel-team-bounces@lists.ubuntu.com","Sender":"\"kernel-team\" "}}]