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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 363BAC433E0 for ; Mon, 22 Feb 2021 15:48:14 +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 7059C64E74 for ; Mon, 22 Feb 2021 15:48:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7059C64E74 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]:45666 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lEDRU-0004xo-BD for qemu-devel@archiver.kernel.org; Mon, 22 Feb 2021 10:48:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40486) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lEDIt-0005wb-36 for qemu-devel@nongnu.org; Mon, 22 Feb 2021 10:39:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56594) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lEDIc-0004FE-SD for qemu-devel@nongnu.org; Mon, 22 Feb 2021 10:39:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614008340; 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=Qmbm4iTjY+ICzOaptRWAoAKmIaPsBh1KdL6bNyn9Wg0=; b=c7kOKWBPvFFnS5TbB3Oeeg5PPVgmQUbw5eGgqcP0TRtZwgESFUzuNOJlVr4TPWZgYuXFph JHB+lMViWKRO/Kl8Ipmq/SOCyNHgYhgETzaUGXAi2s+CWahulb+5ZE7s1v6yE0H4jJZrRD 2qrq6mW8Pm7bXhoRewiY1WzyhodkbYQ= 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-241-etw46VKcP5ym7nXkunnOIQ-1; Mon, 22 Feb 2021 10:38:58 -0500 X-MC-Unique: etw46VKcP5ym7nXkunnOIQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4CE67195D560; Mon, 22 Feb 2021 15:38:57 +0000 (UTC) Received: from [10.36.115.16] (ovpn-115-16.ams2.redhat.com [10.36.115.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id D1ABC19727; Mon, 22 Feb 2021 15:38:40 +0000 (UTC) Subject: Re: [PATCH v6 09/12] softmmu/physmem: Don't use atomic operations in ram_block_discard_(disable|require) To: Paolo Bonzini , qemu-devel@nongnu.org References: <20210222115708.7623-1-david@redhat.com> <20210222115708.7623-10-david@redhat.com> <61237335-b03f-cb89-c0be-03fc3058c13b@redhat.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <9b127669-f84e-7f8c-f76c-2bf7b206d68b@redhat.com> Date: Mon, 22 Feb 2021 16:38:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <61237335-b03f-cb89-c0be-03fc3058c13b@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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_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: Pankaj Gupta , Alex Williamson , Wei Yang , "Michael S . Tsirkin" , "Dr . David Alan Gilbert" , Peter Xu , Auger Eric , Pankaj Gupta , teawater , Igor Mammedov , Marek Kedzierski Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 22.02.21 15:02, Paolo Bonzini wrote: > On 22/02/21 14:33, David Hildenbrand wrote: >>> Also, uncoordinated require is unused, and therefore uncoordinated >>> disable is also never going to block anything.  Does it make sense to >>> keep it in the API? >> >> Right, "ram_block_discard_require()" is not used yet. I am planning on >> using it in virtio-balloon context at some point, but can remove it for >> now to simplify. >> >> ram_block_uncoordinated_discard_disable(), however, will block >> virtio-balloon already via ram_block_discard_is_disabled(). (yes, >> virtio-balloon is ugly) > > Oops, I missed that API. > > Does it make sense to turn the API inside out, with the > coordinated/uncoordinated choice as an argument and the start/finish > choice in the name? > > enum { > RAM_DISCARD_ALLOW_COORDINATED = 1, > }; > Any reason to go with an enum/flags for this case and not "bool allow_coordinated" ? > bool ram_discard_disable(int flags, Error **errp); > void ram_discard_enable(int flags); > int ram_discard_start(bool coordinated, Error **errp); > void ram_discard_finish(bool coordinated); Yeah, I tried to avoid boolean flags ;) Don't have a strong opinion. At least we get shorter names. -- Thanks, David / dhildenb