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 4D9E1E7E653 for ; Tue, 26 Sep 2023 17:05:16 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qlBUP-0007RK-B9; Tue, 26 Sep 2023 13:04:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qlBUM-0007QX-VR for qemu-devel@nongnu.org; Tue, 26 Sep 2023 13:04:47 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qlBUL-00082S-H2 for qemu-devel@nongnu.org; Tue, 26 Sep 2023 13:04:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695747883; 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=n6aPhBmlUNXzLPKQjObc21rIjuIjpl8EuOF1O5lv63c=; b=amL+M0VoqGuZaAOeEPPQq1f/J5Z+7I6R2Fd8DdQDAUpocD7axrFsna3mEayX5TEGHtaItW sR8ZzFIExVZK2iYQNi54eawcZqORRAq+5abMpvL/L714J/ds/EZu7VLUaEfwK/GmWONeHV WL/+L4aW6CxOid1rahwTvVWxYppen0E= Received: from mail-vk1-f197.google.com (mail-vk1-f197.google.com [209.85.221.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-685-SmGZ0NZnP6aFMnMIvwYIDQ-1; Tue, 26 Sep 2023 13:04:42 -0400 X-MC-Unique: SmGZ0NZnP6aFMnMIvwYIDQ-1 Received: by mail-vk1-f197.google.com with SMTP id 71dfb90a1353d-495fe2e308cso1107062e0c.1 for ; Tue, 26 Sep 2023 10:04:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695747882; x=1696352682; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=n6aPhBmlUNXzLPKQjObc21rIjuIjpl8EuOF1O5lv63c=; b=emXJAH5tmgmKjP/d+KtW2hvLy3Xvno4TSNz9VO/b2DGeNvi5LLW0HxbZEXzlmMzA6s euBavvvcepKTTZrSU/w7mvWcJ+Vb1b5vt62mB1kysPvyZNUPytZdEMe56aEjt7ZzPygL 5xRy2c9aqgafyv0kxqZWZKfIRPUldgkiDvHEwTozmCk6kS15Lt8Kuiwk0z2wgej91xUn cw5H0m58ps0jpdbMoABC0QGde0KwCK9Mx7kECc/TkFK4uiiAIW3QSz3sbibUfr/Yjszs yCOjjt9OEMmCUnecz6XCJ8ToQ/ZvMa8IrHHXy7g13DCZJ3oIZO7SYHprMBRzg5uHReu0 gdXg== X-Gm-Message-State: AOJu0YwuS/sLC7+sUb7subb6TAcc+Z3HzuC7We5MbskZuZdy31zDMw4F Pd1NZ6iSKMn5EqyHSq+SyfocHiCL+DctWayuPcmK5F+pOZ/kTpdD1wZS1JhKHU2uttvXk/eHyun cmGJTNnrtNmCfLv8= X-Received: by 2002:a05:6122:a1d:b0:493:a661:c607 with SMTP id 29-20020a0561220a1d00b00493a661c607mr4109021vkn.1.1695747882073; Tue, 26 Sep 2023 10:04:42 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHgWVJ/t7kNFWtxqPp5ExvvLvMY/YsJTdtqkFbbcSzlkTidJQ+vjBrLM1oz1TObqw93oNsOCQ== X-Received: by 2002:a05:6122:a1d:b0:493:a661:c607 with SMTP id 29-20020a0561220a1d00b00493a661c607mr4108986vkn.1.1695747881722; Tue, 26 Sep 2023 10:04:41 -0700 (PDT) Received: from x1n (cpe5c7695f3aee0-cm5c7695f3aede.cpe.net.cable.rogers.com. [99.254.144.39]) by smtp.gmail.com with ESMTPSA id jr2-20020a05622a800200b003eabcc29132sm592531qtb.29.2023.09.26.10.04.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Sep 2023 10:04:41 -0700 (PDT) Date: Tue, 26 Sep 2023 13:04:38 -0400 From: Peter Xu To: Li Zhijian Cc: quintela@redhat.com, leobras@redhat.com, qemu-devel@nongnu.org, Fabiano Rosas Subject: Re: [PATCH v2 1/2] migration: Fix rdma migration failed Message-ID: References: <20230926100103.201564-1-lizhijian@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230926100103.201564-1-lizhijian@fujitsu.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Sep 26, 2023 at 06:01:02PM +0800, Li Zhijian wrote: > Migration over RDMA failed since > commit: 294e5a4034 ("multifd: Only flush once each full round of memory") > with erors: > qemu-system-x86_64: rdma: Too many requests in this message (3638950032).Bailing. > > migration with RDMA is different from tcp. RDMA has its own control > message, and all traffic between RDMA_CONTROL_REGISTER_REQUEST and > RDMA_CONTROL_REGISTER_FINISHED should not be disturbed. > > find_dirty_block() will be called during RDMA_CONTROL_REGISTER_REQUEST > and RDMA_CONTROL_REGISTER_FINISHED, it will send a extra traffic( > RAM_SAVE_FLAG_MULTIFD_FLUSH) to destination and cause migration to fail > even though multifd is disabled. > > This change make migrate_multifd_flush_after_each_section() return true > when multifd is disabled, that also means RAM_SAVE_FLAG_MULTIFD_FLUSH > will not be sent to destination any more when multifd is disabled. > > Fixes: 294e5a4034 ("multifd: Only flush once each full round of memory") > CC: Fabiano Rosas > Signed-off-by: Li Zhijian > --- > > V2: put that check at the entry of migrate_multifd_flush_after_each_section() # Peter When seeing this I notice my suggestion wasn't ideal either, as we rely on both multifd_send_sync_main() and multifd_recv_sync_main() be no-op when !multifd. For the long term, we should not call multifd functions at all, if multifd is not enabled.. Reviewed-by: Peter Xu -- Peter Xu