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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 DC2D3C433DB for ; Tue, 2 Mar 2021 21:11:31 +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 5E61C64F20 for ; Tue, 2 Mar 2021 21:11:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E61C64F20 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]:60932 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lHCIk-0001bV-3m for qemu-devel@archiver.kernel.org; Tue, 02 Mar 2021 16:11:30 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48224) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lHC79-0006Zv-LQ for qemu-devel@nongnu.org; Tue, 02 Mar 2021 15:59:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55326) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lHC77-0000zi-P9 for qemu-devel@nongnu.org; Tue, 02 Mar 2021 15:59:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614718766; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LFeFwgd416hJgfI8CWTw0qkdzSGitcUKICDrANuntTg=; b=XLN/KyCobY5mv7LN0QlS3SJnyobSGgqHpgH3BD/GSyLmr9jSI5eM+8IDKoCHZMiv8GO0qG /ZQvAD6jYXoKuYAHs+AZw3Gox3TTloqUMBpDKkP7tW9IJZ+Wh3gvHyTGP2d2SfNvnRYLB5 ij9LWbcbbDTwrFghEzBBgfFtSgJG7eY= 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-287-3qt4LCbVM_iATpODKkWvrA-1; Tue, 02 Mar 2021 15:59:23 -0500 X-MC-Unique: 3qt4LCbVM_iATpODKkWvrA-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 5014A193578B; Tue, 2 Mar 2021 20:59:21 +0000 (UTC) Received: from [10.36.112.56] (ovpn-112-56.ams2.redhat.com [10.36.112.56]) by smtp.corp.redhat.com (Postfix) with ESMTP id 034C05D9C2; Tue, 2 Mar 2021 20:58:46 +0000 (UTC) Subject: Re: [PATCH v1 7/9] memory: introduce RAM_NORESERVE and wire it up in qemu_ram_mmap() To: Peter Xu References: <20210209134939.13083-1-david@redhat.com> <20210209134939.13083-8-david@redhat.com> <20210302173243.GM397383@xz-x1> <91613148-9ade-c192-4b73-0cb5a54ada98@redhat.com> <20210302205432.GP397383@xz-x1> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <9b7294f9-5269-0429-265d-47cf9c9b33c9@redhat.com> Date: Tue, 2 Mar 2021 21:58:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210302205432.GP397383@xz-x1> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Received-SPF: pass client-ip=216.205.24.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no 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: Thomas Huth , Cornelia Huck , Eduardo Habkost , kvm@vger.kernel.org, "Michael S. Tsirkin" , qemu-s390x@nongnu.org, Stefan Weil , Murilo Opsfelder Araujo , Richard Henderson , "Dr. David Alan Gilbert" , Juan Quintela , qemu-devel@nongnu.org, Halil Pasic , Christian Borntraeger , Greg Kurz , Stefan Hajnoczi , Igor Mammedov , Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Igor Kotrasinski Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 02.03.21 21:54, Peter Xu wrote: > On Tue, Mar 02, 2021 at 08:02:34PM +0100, David Hildenbrand wrote: >>>> @@ -174,12 +175,18 @@ void *qemu_ram_mmap(int fd, >>>> size_t align, >>>> bool readonly, >>>> bool shared, >>>> - bool is_pmem) >>>> + bool is_pmem, >>>> + bool noreserve) >>> >>> Maybe at some point we should use flags too here to cover all bools. >>> >> >> Right. I guess the main point was to not reuse RAM_XXX. >> >> Should I introduce RAM_MMAP_XXX ? > > Maybe we can directly use MAP_*? Since I see qemu_ram_mmap() should only exist I think the issue is that there is for example no flag that corresponds to "is_pmem" - and the fallback logic in our mmap code to make "is_pmem" still work is a little bit more involved. In addition, "readonly" translates to PROT_READ ... > with CONFIG_POSIX. However indeed I see no sign to extend more bools in the > near future either, so maybe also fine to keep it as is, as 4 bools still looks > okay - your call. :) Well, I had the same idea when I added yet another bool :) But I guess we won't be adding a lot of additional flags in the near future. (MAP_POPULATE? ;) fortunately we use a different approach to populate memory) I'll think about it, not sure yet if this is worth proper flags. Thanks! -- Thanks, David / dhildenb