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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 97305C433E0 for ; Mon, 22 Jun 2020 08:13:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 615B9206D4 for ; Mon, 22 Jun 2020 08:13:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iw2ynLgB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 615B9206D4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50856 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jnHZv-0004A5-NC for qemu-devel@archiver.kernel.org; Mon, 22 Jun 2020 04:13:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59018) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jnHYs-0003S3-5H for qemu-devel@nongnu.org; Mon, 22 Jun 2020 04:12:14 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:46026 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jnHYq-0006MS-AY for qemu-devel@nongnu.org; Mon, 22 Jun 2020 04:12:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592813531; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Ln6sPXc1yu1Wx8IzGGYx4x46BuVGfWg9Mnw7BZnmYV4=; b=iw2ynLgBD3I1dlKsnXBrkMq6EU7bYfEDSw+i4RRBiV+YXcIZoobUTGxG8GFDAhpDvrPMQf uNS+LvbdMfgJWSXviZnr2ZqUjLsQhSnsc4Hk8J0faxwykMHK+YEYnkPYbhTgoEz606TVvu Ag3cDxak3IbLTXpdXd0d6ntRFlOQuF0= 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-86-qRiW5apiNcez3ztuSBJoZQ-1; Mon, 22 Jun 2020 04:12:07 -0400 X-MC-Unique: qRiW5apiNcez3ztuSBJoZQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DA462107ACF3; Mon, 22 Jun 2020 08:12:06 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-121.ams2.redhat.com [10.36.112.121]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BBD2A5C220; Mon, 22 Jun 2020 08:12:03 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 30F96113846D; Mon, 22 Jun 2020 10:12:02 +0200 (CEST) From: Markus Armbruster To: Michal Privoznik Subject: Re: [PATCH v2 2/2] qemu-options.hx: Document hmat-lb and hmat-cache order References: <5bd3f4a03227658cbdb1d184518c7805c1c0122f.1591794890.git.mprivozn@redhat.com> <877dw8bvu5.fsf@dusky.pond.sub.org> <8de1babf-0925-eda0-9d30-a765aff0c4df@redhat.com> Date: Mon, 22 Jun 2020 10:12:02 +0200 In-Reply-To: <8de1babf-0925-eda0-9d30-a765aff0c4df@redhat.com> (Michal Privoznik's message of "Tue, 16 Jun 2020 08:46:11 +0200") Message-ID: <878sgfr031.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=205.139.110.120; envelope-from=armbru@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/22 01:27:42 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Igor Mammedov , Tao Xu , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Liu Jingqi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Michal Privoznik writes: > On 6/15/20 10:02 AM, Markus Armbruster wrote: >> Michal Privoznik writes: >> >>> To simplify internal implementation the hmat-cache parsing code >>> expects hmat-lb to be already parsed. This means, that hmat-lb >>> arguments must come before hmat-cache. Document this restriction >>> so that management applications can follow it. >>> >>> Signed-off-by: Michal Privoznik >>> --- >>> qemu-options.hx | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/qemu-options.hx b/qemu-options.hx >>> index b1a399079a..3fe9e6d6a0 100644 >>> --- a/qemu-options.hx >>> +++ b/qemu-options.hx >>> @@ -319,6 +319,9 @@ SRST >>> 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy >>> is the write policy. line is the cache Line size in bytes. >>> + Please note, that due to internal implementation, '\ >>> ``hmat-cache``\ ' >>> + must be configured only after '\ ``hmat-lb``\ ' option. >>> + >>> For example, the following options describe 2 NUMA nodes. Node 0 has >>> 2 cpus and a ram, node 1 has only a ram. The processors in node 0 >>> access memory in node 0 with access-latency 5 nanoseconds, >> >> What happens when we do it wrong? >> > > We error out. > > https://lists.nongnu.org/archive/html/qemu-devel/2020-05/msg08409.html Good. >> Can we catch doing it wrong somehow? I figure that would be much better >> than merely documenting it. >> > > Sure, but that would require some more code (according to Igor's > e-mail and discussion linked from the linked document). And frankly, > to libvirt it doesn't matter. For everybody else, let's document it at > least and if somebody ever writes the missing piece we can remove the > restriction from the docs. Misunderstanding. By "catch doing it wrong", I mean "error out when hmat-cache is configured before hmat-lb". I understand we do that. Avoiding the restriction entirely would be even better, but the maintainer obviously decided it was not worth the trouble. I gladly defer to the maintainer here. Given the general undocumentedness of similar restrictions elsewhere, I can't bring myself to care for documenting this one. Up to the maintainer.