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 54FC1C433EF for ; Tue, 7 Dec 2021 07:32:47 +0000 (UTC) Received: from localhost ([::1]:34610 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1muUxx-0004fe-VU for qemu-devel@archiver.kernel.org; Tue, 07 Dec 2021 02:32:45 -0500 Received: from eggs.gnu.org ([209.51.188.92]:53616) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1muUw8-0003nN-UJ for qemu-devel@nongnu.org; Tue, 07 Dec 2021 02:30:53 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41793) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1muUw6-0001GD-8n for qemu-devel@nongnu.org; Tue, 07 Dec 2021 02:30:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638862249; 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=B1SjCoLnKMM3k9JJaQDJq5N+2CDURBj2hAD5cMFvVQQ=; b=gjWRf5kw9ZLBQsqcPjTxN3B4SnbRCMAhlsw2UHSDq6ZptcPlaWCBebJO8shd/ugZqpMgVU j9P+P2CnE4MqtH8qY/jJguIPqOb4Os6BOOhl5yn/4UVBmHxtnNr5qxY9dQ7/UocC1OL+OX kOIbP/JRH53ewZoVwZP2SHyyiAhSRD0= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-220-6rp26Q2iOjaQ_oJhBjKAaQ-1; Tue, 07 Dec 2021 02:30:47 -0500 X-MC-Unique: 6rp26Q2iOjaQ_oJhBjKAaQ-1 Received: by mail-wm1-f72.google.com with SMTP id j25-20020a05600c1c1900b00332372c252dso990285wms.1 for ; Mon, 06 Dec 2021 23:30:47 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=B1SjCoLnKMM3k9JJaQDJq5N+2CDURBj2hAD5cMFvVQQ=; b=Z05jM4WBUO0/AAwdkSfyIJHkMJezdbhoKCJ3PJtt7oAakXxVCXl4FOgsz+gsitmfm2 V7TIwZRBAprWvR+nzsp1Du/7lMvnsIlfbrTXh8m/HS0GwUYILvwXOHWFQTVp5cUVrsxs mjtX7w6gMoQ5zo6MobpIR4ArgaLuvz6dC8Q1O7M54M5bxNcbRghv6tXkIIm3pvfIVfeK WESqYdQ0GSDNdhZAjM20ON+hN9BDNZTUXNYFGwJORsEjqz/M06q7QxgcT8d7qe4qNaVc AT3CJ4mXwnkavAgFQ6PvS2VVKXgeIqk6cKdZRuByJnjsZzbsNtYbHEpOYlP2jLfLOwlt Nbdg== X-Gm-Message-State: AOAM533O2s1MyZNo5sFNgdvhoLjrGp9gOI9FYgOHbtKxN5Ll1vmCb+TS F2HkbrKS0lHkoyYXXVJJyowoo03SKqR36uRWZZa7I10FFRQ/8aJ+1z2OLr8mX4Y4du/dFokkvpZ +krEyb3M+A3XPjKI= X-Received: by 2002:adf:ef52:: with SMTP id c18mr49633730wrp.162.1638862246559; Mon, 06 Dec 2021 23:30:46 -0800 (PST) X-Google-Smtp-Source: ABdhPJzGFLKoZJC0ub4VY+ETdoBNSLNUc6i+0fBKtrFC9jJ/Hvjzr7Gj2EJuNTN2Kln0Xc9sbpyr4g== X-Received: by 2002:adf:ef52:: with SMTP id c18mr49633713wrp.162.1638862246385; Mon, 06 Dec 2021 23:30:46 -0800 (PST) Received: from xz-m1.local ([85.203.46.174]) by smtp.gmail.com with ESMTPSA id z6sm1865062wmp.9.2021.12.06.23.30.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Dec 2021 23:30:45 -0800 (PST) Date: Tue, 7 Dec 2021 15:30:41 +0800 From: Peter Xu To: Juan Quintela Subject: Re: [PATCH v3 23/23] migration: Use multifd before we check for the zero page Message-ID: References: <20211124100617.19786-1-quintela@redhat.com> <20211124100617.19786-24-quintela@redhat.com> <87fsragb58.fsf@secure.mitica> MIME-Version: 1.0 In-Reply-To: <87fsragb58.fsf@secure.mitica> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.619, 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_H2=-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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Leonardo Bras , "Dr. David Alan Gilbert" , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Dec 02, 2021 at 06:38:27PM +0100, Juan Quintela wrote: > This needs to be improved to be compatible with old versions. Any plan to let new binary work with old binary? Maybe boost the version field for multifd packet (along with a multifd_version=2 parameter and only set on new machine types)? PS: We should really have some handshake mechanism between src/dst, I dreamt it for a long time.. So that we only need to specify the capability/parameters on src someday and we'll never see incompatible migration failing randomly because the handshake should guarantee no stupid mistake.. Sad. > > But .... if we don't care about RDMA, why do we care about > control_save_page()? Could anyone help to explain why we don't care? I still see bugfixes coming.. Thanks, -- Peter Xu