From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id 3F85E3894C35 for ; Mon, 28 Sep 2020 14:03:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 3F85E3894C35 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-470-s5-P8hsFPs2Qw_RokK491w-1; Mon, 28 Sep 2020 10:03:27 -0400 X-MC-Unique: s5-P8hsFPs2Qw_RokK491w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C7B1310BBEC0; Mon, 28 Sep 2020 14:03:26 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-114-84.ams2.redhat.com [10.36.114.84]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DBF2C5D9CA; Mon, 28 Sep 2020 14:03:25 +0000 (UTC) From: Florian Weimer To: "H.J. Lu" Cc: "H.J. Lu via Libc-alpha" , Siddhesh Poyarekar Subject: Re: [PATCH 2/4] Set tunable value as well as min/max values References: <20200918160709.949608-1-hjl.tools@gmail.com> <20200918160709.949608-3-hjl.tools@gmail.com> <87eemm6n37.fsf@oldenburg2.str.redhat.com> Date: Mon, 28 Sep 2020 16:03:24 +0200 In-Reply-To: (H. J. Lu's message of "Mon, 28 Sep 2020 06:53:09 -0700") Message-ID: <87zh5a5783.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=unavailable autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Sep 2020 14:03:31 -0000 * H. J. Lu: > On Mon, Sep 28, 2020 at 6:35 AM Florian Weimer wrote: >> >> * H. J. Lu via Libc-alpha: >> >> > Some tunable values and their minimum/maximum values must be determinted >> > at run-time. Add TUNABLE_SET_ALL and TUNABLE_SET_ALL_FULL to update >> > tunable value together with minimum and maximum values. __tunable_set_val >> > is updated to set tunable value as well as min/max values. >> >> I'm not sure if this change is philosophically correct as far as the >> tunables framework is concerned. I had thought the limits should be >> something static, so that they are consistent across systems. > > Some x86 tunables ranges are dynamic. > >> Maybe Siddhesh can comment on that aspect? >> >> What is supposed to happen if you specify an out-of-range value? > > It should be rejected. Otherwise programs will crash. You could still do this outside the tunables framework, I think. Let's wait for Siddhesh's comments. Thanks, Florian -- Red Hat GmbH, https://de.redhat.com/ , Registered seat: Grasbrunn, Commercial register: Amtsgericht Muenchen, HRB 153243, Managing Directors: Charles Cachera, Brian Klemm, Laurie Krebs, Michael O'Neill