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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,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 46C3BC433ED for ; Fri, 23 Apr 2021 11:34:45 +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 70A2461139 for ; Fri, 23 Apr 2021 11:34:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70A2461139 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]:48482 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lZu55-0002vH-5T for qemu-devel@archiver.kernel.org; Fri, 23 Apr 2021 07:34:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39476) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZu3u-0002UL-0n for qemu-devel@nongnu.org; Fri, 23 Apr 2021 07:33:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:45265) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lZu3r-0006yb-6s for qemu-devel@nongnu.org; Fri, 23 Apr 2021 07:33:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619177604; 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=0wIYFMNenptGsVd26zWu3RWUZSvpT87lh7OqPAk28gs=; b=OvJFjwwjSu4NDKzvApr3HlRZvWSmgR8qKHKPkuKIhxK1VJqYkL4k51s7cb6d/jM15QPKKV q4J1LhBKT4mFYID2h75PF4fkIQRbVZAzarMZxXqIZiqKu2UUhVoNMPAvALD4AAN0V8leLz v3adSBRS+fGaZNzX1kcycIdPLTDjzPw= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-437-xNS1l7NDMDuajHCMzPTnlQ-1; Fri, 23 Apr 2021 07:33:23 -0400 X-MC-Unique: xNS1l7NDMDuajHCMzPTnlQ-1 Received: by mail-wm1-f70.google.com with SMTP id c2-20020a1cb3020000b029013850c82dbcso629585wmf.5 for ; Fri, 23 Apr 2021 04:33:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:references:from:organization:subject :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=0wIYFMNenptGsVd26zWu3RWUZSvpT87lh7OqPAk28gs=; b=gGaL4ZJuXToWAhQlk037JJl0vtnHBWFMcI9skEhUxd4ki1e7nrZ1JD0tAWL+X43KVv jxhOrSjXl/PsI5Vqc2cNbyAZcCllHvY/39lw1BvYxqo2nfT4Cmiagjmns+uZ4uCjZGXo vjdSCgvu/dV8j47dcZ2orcJ1NIYyCL8WwSUINHkmLRaYGNEDs4t26GVXizcXMV4h0tmK vvtfoJC668d90LxsqPztYwR4n0W5zFBimumOjZEfARzvaAlAXQcYwPi2z934Y6zSqpbY vWUYMNbO3DNcMngygs2lOHb/PvegNXrxaycCAApAdkukxxeYYTIC98vsSdc2N67A1HVR 5YeQ== X-Gm-Message-State: AOAM5313eRH8Z6hpt9GoG3G7whl/PnhEohQ2eABFoC5GP2/9oCNxXV9T j9LOuVnVNDB8PRdnO1nRNOzrywA6ZsvSThDkkXG5G03yxnHWTWsUh55AKx63hc1w57jbwGf0gvL rXNbKnAA56OO6P6Y= X-Received: by 2002:adf:fccd:: with SMTP id f13mr4245636wrs.222.1619177602105; Fri, 23 Apr 2021 04:33:22 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyKFI1KVwebEyNBiNDuejjlVz3MDdzUwwuOKJEVU1Q316nFZZmri1ehJqsq1j1F+cu0z/qkxA== X-Received: by 2002:adf:fccd:: with SMTP id f13mr4245605wrs.222.1619177601876; Fri, 23 Apr 2021 04:33:21 -0700 (PDT) Received: from [192.168.3.132] (p5b0c6365.dip0.t-ipconnect.de. [91.12.99.101]) by smtp.gmail.com with ESMTPSA id c12sm9030557wro.6.2021.04.23.04.33.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 23 Apr 2021 04:33:21 -0700 (PDT) To: Markus Armbruster References: <20210421122624.12292-1-david@redhat.com> <20210421122624.12292-15-david@redhat.com> <87im4di7u9.fsf@dusky.pond.sub.org> <190f173c-b3f9-6c70-42bb-27f50a5f9380@redhat.com> <87h7jxgsa0.fsf@dusky.pond.sub.org> From: David Hildenbrand Organization: Red Hat Subject: Re: [PATCH v6 14/15] qmp: Include "reserve" property of memory backends Message-ID: <79cdbd39-cf5c-a8ab-b2c9-68d8e4ab2333@redhat.com> Date: Fri, 23 Apr 2021 13:33:20 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <87h7jxgsa0.fsf@dusky.pond.sub.org> 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: 8bit 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_H4=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: Marcel Apfelbaum , Eduardo Habkost , "Michael S. Tsirkin" , Richard Henderson , qemu-devel@nongnu.org, Peter Xu , "Dr. David Alan Gilbert" , Greg Kurz , Stefan Hajnoczi , Murilo Opsfelder Araujo , Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Igor Mammedov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 23.04.21 13:21, Markus Armbruster wrote: > David Hildenbrand writes: > >> On 23.04.21 13:00, Markus Armbruster wrote: >>> David Hildenbrand writes: >>> >>>> Let's include the new property. >>>> >>>> Reviewed-by: Philippe Mathieu-Daudé >>>> Cc: Eric Blake >>>> Cc: Markus Armbruster >>>> Cc: Igor Mammedov >>>> Signed-off-by: David Hildenbrand >>>> --- >>>> hw/core/machine-qmp-cmds.c | 1 + >>>> qapi/machine.json | 4 ++++ >>>> 2 files changed, 5 insertions(+) >>>> >>>> diff --git a/hw/core/machine-qmp-cmds.c b/hw/core/machine-qmp-cmds.c >>>> index d41db5b93b..2d135ecdd0 100644 >>>> --- a/hw/core/machine-qmp-cmds.c >>>> +++ b/hw/core/machine-qmp-cmds.c >>>> @@ -175,6 +175,7 @@ static int query_memdev(Object *obj, void *opaque) >>>> m->dump = object_property_get_bool(obj, "dump", &error_abort); >>>> m->prealloc = object_property_get_bool(obj, "prealloc", &error_abort); >>>> m->share = object_property_get_bool(obj, "share", &error_abort); >>>> + m->reserve = object_property_get_bool(obj, "reserve", &error_abort); >>>> m->policy = object_property_get_enum(obj, "policy", "HostMemPolicy", >>>> &error_abort); >>>> host_nodes = object_property_get_qobject(obj, >>>> diff --git a/qapi/machine.json b/qapi/machine.json >>>> index 32650bfe9e..5932139d20 100644 >>>> --- a/qapi/machine.json >>>> +++ b/qapi/machine.json >>>> @@ -798,6 +798,9 @@ >>>> # >>>> # @share: whether memory is private to QEMU or shared (since 6.1) >>>> # >>>> +# @reserve: whether swap space (or huge pages) was reserved if applicable >>>> +# (since 6.1) >>>> +# >>>> # @host-nodes: host nodes for its memory policy >>>> # >>>> # @policy: memory policy of memory backend >>>> @@ -812,6 +815,7 @@ >>>> 'dump': 'bool', >>>> 'prealloc': 'bool', >>>> 'share': 'bool', >>>> + 'reserve': 'bool', >>>> 'host-nodes': ['uint16'], >>>> 'policy': 'HostMemPolicy' }} >>> >>> Double-checking: true means definitely reserved, and false means >>> definitely not reserved. Correct? >> >> True means "reserved if applicable" which means "not reserved if not >> applicable". False means "definitely not reserved". >> >> (any recommendation how to rephrase are appreciated; I tried my best -- >> this interface here makes it especially hard -- it's easier for the >> property itself) > > When is it "applicable"? > When the OS supports it for the memory type and it hasn't been disabled. Linux handling as described in [PATCH v6 09/15] util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux and https://www.kernel.org/doc/Documentation/vm/overcommit-accounting Summary *without* MAP_NORESERVE: a) !Hugetlbfs with Memory overcommit disabled via ("/proc/sys/vm/overcommit_memory == 2"): never b) !Hugetlbfs with Memory overcommit enabled 1) Shared mappings on files: never 2) Private mappings on files: only when writable (for us always) 3) Shared anonymous memory: always 4) Private anonymous memory: only when writable (for us always) c) Hugetlbfs: Always Under Windows: always. On other POSIX besides Linux -- don't know. -- Thanks, David / dhildenb