From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 633C7C43460 for ; Tue, 27 Apr 2021 15:00:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45D95613E5 for ; Tue, 27 Apr 2021 15:00:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237424AbhD0PBP (ORCPT ); Tue, 27 Apr 2021 11:01:15 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:22686 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236710AbhD0PBO (ORCPT ); Tue, 27 Apr 2021 11:01:14 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13REX77C150032; Tue, 27 Apr 2021 10:59:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=+QlamBl19HO/Z+/EikQ6Mdam0domaFKqNPPFu7gdiHg=; b=Fla/1GQ052qfVp80lcNJgB52juyMtdxf7DoNbSbDGYfCt9Mg9l/a/Z9B+a4cY7Sul7CA ywlQZ9nrkkSAK+XSb8tbw/p7RnOL6sUgeyr1DBD1Y6SnfzTrjsv7vEa0URi3DNpAGc/p NltUxHwIBw/LICmCEBs2aEuQ5XG6/Iz0UoHooNpQOGkTarbLq6E8jmOwzilJBBVi+oCG YS4cmxFmMf89tVLL/RjjK+Ec98cudUkRrRbMmK0/42WJzNraGW5G6jQgr+zZt6rRK888 +SRzzep2ZpNQY0TQ8F8xO3r2V1vBUChMLj0COjjpczYI0cZA3aq+RYa8cQKf4td13BdJ SA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 386cf38bj5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 27 Apr 2021 10:59:32 -0400 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 13REYJGJ154559; Tue, 27 Apr 2021 10:59:32 -0400 Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 386cf38bh7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 27 Apr 2021 10:59:32 -0400 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 13REw7Od006549; Tue, 27 Apr 2021 14:59:29 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma05fra.de.ibm.com with ESMTP id 384gjxrr9n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 27 Apr 2021 14:59:29 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 13REx1YU34668996 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 27 Apr 2021 14:59:02 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 21F1A11C050; Tue, 27 Apr 2021 14:59:26 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0DEC711C04C; Tue, 27 Apr 2021 14:59:26 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 27 Apr 2021 14:59:26 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id C0F6CE028D; Tue, 27 Apr 2021 16:59:25 +0200 (CEST) From: Christian Borntraeger To: peterz@infradead.org Cc: bristot@redhat.com, bsegall@google.com, dietmar.eggemann@arm.com, greg@kroah.com, gregkh@linuxfoundation.org, joshdon@google.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk, mgorman@suse.de, mingo@kernel.org, rostedt@goodmis.org, valentin.schneider@arm.com, vincent.guittot@linaro.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, borntraeger@de.ibm.com Subject: Re: sched: Move SCHED_DEBUG sysctl to debugfs Date: Tue, 27 Apr 2021 16:59:25 +0200 Message-Id: <20210427145925.5246-1-borntraeger@de.ibm.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210412102001.287610138@infradead.org> References: <20210412102001.287610138@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: eKX2-Ma5Wve74Wy6SnaoNJ_DMaO9FzIX X-Proofpoint-ORIG-GUID: oKwvlBcQkWFx-YEwG_gOPg9dEDJ3vNAT X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-04-27_08:2021-04-27,2021-04-27 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 mlxlogscore=823 bulkscore=0 spamscore=0 mlxscore=0 adultscore=0 phishscore=0 lowpriorityscore=0 priorityscore=1501 clxscore=1011 malwarescore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104270105 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Peter, I just realized that we moved away sysctl tunabled to debugfs in next. We have seen several cases where it was benefitial to set sched_migration_cost_ns to a lower value. For example with KVM I can easily get 50% more transactions with 50000 instead of 500000. Until now it was possible to use tuned or /etc/sysctl.conf to set these things permanently. Given that some people do not want to have debugfs mounted all the time I would consider this a regression. The sysctl tunable was always available. I am ok with the "informational" things being in debugfs, but not the tunables. So how do we proceed here? Christian