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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8F449C433EF for ; Tue, 5 Apr 2022 11:03:47 +0000 (UTC) Received: from localhost ([::1]:58790 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nbgyQ-0002Vz-Ae for qemu-devel@archiver.kernel.org; Tue, 05 Apr 2022 07:03:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33906) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nbgey-0002M7-IP for qemu-devel@nongnu.org; Tue, 05 Apr 2022 06:43:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:25207) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nbgev-0003bd-8a for qemu-devel@nongnu.org; Tue, 05 Apr 2022 06:43:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649155416; 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=DPpFKAQwvJ2LoKajZ6WKCwpW66sfmX+A++otVDf52to=; b=URdbrwHya6GqTzJ6Lr7Zp0fGqD/88eDjiy0gQiHuXKbS6Hpbeki82cjgu372nullijcgy+ axng6+pbZtUUHgNVFvr5689bk1ANRlAKvaOxi4C61B3dLpv20l6qri3WY67CvUW2CPPQ6Z IVqlFyKviW8aU63o76DiPIHkBTh5AA4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-237-881ExVlDMzCB14stKDg3XA-1; Tue, 05 Apr 2022 06:43:35 -0400 X-MC-Unique: 881ExVlDMzCB14stKDg3XA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C19F11C02328; Tue, 5 Apr 2022 10:43:34 +0000 (UTC) Received: from redhat.com (unknown [10.39.194.82]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6B659C15D75; Tue, 5 Apr 2022 10:43:33 +0000 (UTC) Date: Tue, 5 Apr 2022 12:43:32 +0200 From: Kevin Wolf To: Paolo Bonzini Subject: Re: [RFC PATCH 0/5] Removal of AioContext lock, bs->parents and ->children: proof of concept Message-ID: References: <88f2798b-9327-e54f-5792-e37404b94ef7@redhat.com> <8ae70388-ff46-6ec1-7f84-14d41ca9a6dd@redhat.com> <311c2e0a-fb2c-241c-cbd1-1162f7e74e18@redhat.com> <9d3c36f0-0834-ec9c-8473-d052d64a61dd@redhat.com> <69b2ce82-4826-71ed-9c32-d323df69b7c4@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Emanuele Giuseppe Esposito , Fam Zheng , Vladimir Sementsov-Ogievskiy , "open list:Block layer core" , qemu-devel , Hanna Reitz , Stefan Hajnoczi , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 04.04.2022 um 11:41 hat Paolo Bonzini geschrieben: > As an aside, instead of is_external, QEMU could remove/add the ioeventfd > handler in the blk->dev_ops->drained_begin and blk->dev_ops->drained_end > callbacks respectively. But that's just a code cleanup. Yes, this is the proper way to do it that we intended to implement "sometime later". aio_disable_external() is really an ugly hack. I assume that with multiqueue, we'll have to rework this anyway because there won't be a single AioContext to disable any more - and I'm not sure if a node will even know from which AioContexts requests could potentially be sent to it. So we may have to go through the proper callback mechanisms at that point. Kevin