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 1D210C433DB for ; Fri, 5 Mar 2021 15:46:31 +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 8FF8C6508D for ; Fri, 5 Mar 2021 15:46:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8FF8C6508D 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]:38796 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lICer-0004FK-MI for qemu-devel@archiver.kernel.org; Fri, 05 Mar 2021 10:46:29 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38730) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lICdP-0002si-Cp for qemu-devel@nongnu.org; Fri, 05 Mar 2021 10:44:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:32708) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lICdL-0006wx-PA for qemu-devel@nongnu.org; Fri, 05 Mar 2021 10:44:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614959093; 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=fOJ80+F+QG4aAms3w0j+8D/iVtdTGNJJnvpvPCt385g=; b=bwBJHpOp7qH9+nHKQ28pfYKdToVHlZTrTtkAVgE1y3tEhVe9PLa5ycL5yyutyZId1gcckR XZM7jEjjNYP/t5PKH3CP5pFxNXuSOGIAd/jCJN9YvDl5euNtgQDPY7pRHApamCcFRmccgj ZtRW2f7JdKWxFGkhMRTBpdJ9fFZF4No= 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-41-xMkHIZgLO4-Eij71CphQlw-1; Fri, 05 Mar 2021 10:44:52 -0500 X-MC-Unique: xMkHIZgLO4-Eij71CphQlw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 60EB9800D53; Fri, 5 Mar 2021 15:44:50 +0000 (UTC) Received: from [10.36.112.194] (ovpn-112-194.ams2.redhat.com [10.36.112.194]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6180A6A046; Fri, 5 Mar 2021 15:44:37 +0000 (UTC) Subject: Re: [PATCH v2 8/9] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE To: Peter Xu References: <20210305101634.10745-1-david@redhat.com> <20210305101634.10745-9-david@redhat.com> <20210305154206.GH397383@xz-x1> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: Date: Fri, 5 Mar 2021 16:44:36 +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: <20210305154206.GH397383@xz-x1> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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=ham 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 , "Michael S. Tsirkin" , 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 05.03.21 16:42, Peter Xu wrote: > On Fri, Mar 05, 2021 at 11:16:33AM +0100, David Hildenbrand wrote: >> +#define OVERCOMMIT_MEMORY_PATH "/proc/sys/vm/overcommit_memory" >> +static bool map_noreserve_effective(int fd, bool readonly, bool shared) >> +{ > > [...] > >> @@ -184,8 +251,7 @@ void *qemu_ram_mmap(int fd, >> size_t offset, total; >> void *ptr, *guardptr; >> >> - if (noreserve) { >> - error_report("Skipping reservation of swap space is not supported"); >> + if (noreserve && !map_noreserve_effective(fd, shared, readonly)) { > > Need to switch "shared" & "readonly"? Indeed, interestingly it has the same effect (as we don't have anonymous read-only memory in QEMU :) ) (wouldn't have happened with flags ... hmm) Thanks! -- Thanks, David / dhildenb