From patchwork Fri Apr 17 11:29:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Pisati X-Patchwork-Id: 1272193 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) 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: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 493Ym324Zzz9sSc; Fri, 17 Apr 2020 21:29:55 +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 1jPPBt-000775-3P; Fri, 17 Apr 2020 11:29:49 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jPPBr-00076t-20 for kernel-team@lists.ubuntu.com; Fri, 17 Apr 2020 11:29:47 +0000 Received: from 1.general.ppisati.uk.vpn ([10.172.193.134] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jPPBq-00038f-OW for kernel-team@lists.ubuntu.com; Fri, 17 Apr 2020 11:29:46 +0000 From: Paolo Pisati To: kernel-team@lists.ubuntu.com Subject: [PATCH 0/1][SRU][F/master] [Config] lowlatency: turn off Date: Fri, 17 Apr 2020 13:29:45 +0200 Message-Id: <20200417112946.51881-1-paolo.pisati@canonical.com> X-Mailer: git-send-email 2.25.1 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/1873315 Impact: Software that requires RT priority is not working anymore since we turned on RT_GROUP_SCHED: commit 9b039fc517876d312e7fa0955571101a299c91f5 Author: Seth Forshee Date: Mon Apr 6 07:11:44 2020 -0500 UBUNTU: [Config] CONFIG_RT_GROUP_SCHED=y This is wanted by docker, and the original reason for disabling it no longer applied. Performance testing shows no noticible impact when the option is enabled. We already experienced this issue in the past (see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1284731), but nowadays reverting RT_GROUP_SCHED back to off would regress Docker and since RT privileges are usually required by audio/multimedia software, it probably makes sense to revert this change only for -lowlatency (while keeping the rest as is) and encourage people to use -lowlatency if they hit this problem. Fix: Apply the attached patch Regression potential: None, only -lowlatency is impacted, -generic doesn't change. Paolo Pisati (1): UBUNTU: [Config] lowlatency: turn off RT_GROUP_SCHED debian.master/config/amd64/config.flavour.generic | 1 + debian.master/config/amd64/config.flavour.lowlatency | 1 + debian.master/config/annotations | 5 ++++- debian.master/config/arm64/config.common.arm64 | 1 + debian.master/config/armhf/config.common.armhf | 1 + debian.master/config/config.common.ubuntu | 1 - debian.master/config/i386/config.common.i386 | 1 + debian.master/config/ppc64el/config.common.ppc64el | 1 + debian.master/config/s390x/config.common.s390x | 1 + 9 files changed, 11 insertions(+), 2 deletions(-) Acked-by: Andrea Righi