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 9C31AC54798 for ; Thu, 29 Feb 2024 06:03:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rfZUU-0001D4-Cf; Thu, 29 Feb 2024 01:01:58 -0500 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 1rfZTw-0000is-BZ for qemu-devel@nongnu.org; Thu, 29 Feb 2024 01:01:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfZTu-0001YE-Lv for qemu-devel@nongnu.org; Thu, 29 Feb 2024 01:01:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709186476; 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=RONNTHZf92nQV0h2lJYMSRMs5sjrOZwNtaxC/Fr2M58=; b=KgQmDAR7Qnpuh1oosTwCbAdBbF/vv5YdRXDKtT95gSbeVrt96d+sEqfwMIz/HN+g+fvAgP mR8ENy4yfD40uxVnxHtCTuYAHG6uLs0qBXfvQY8KLMhJAoeV4raTn+6NktozObu/3qb6QM 5/x7KnoyV3AkuMgmC9xvRezyCY3+f18= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-184-QaTAkLG9OuaXjrrqq59S7g-1; Thu, 29 Feb 2024 01:01:14 -0500 X-MC-Unique: QaTAkLG9OuaXjrrqq59S7g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 592CC3813F30; Thu, 29 Feb 2024 06:01:14 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 077FB1121312; Thu, 29 Feb 2024 06:01:13 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 8729D21E66D0; Thu, 29 Feb 2024 07:01:12 +0100 (CET) From: Markus Armbruster To: Hao Xiang Cc: pbonzini@redhat.com, berrange@redhat.com, eduardo@habkost.net, peterx@redhat.com, farosas@suse.de, eblake@redhat.com, thuth@redhat.com, lvivier@redhat.com, jdenemar@redhat.com, marcel.apfelbaum@gmail.com, philmd@linaro.org, wangyanan55@huawei.com, qemu-devel@nongnu.org Subject: Re: [External] Re: [PATCH v3 6/7] migration/multifd: Add zero pages and zero bytes counter to migration status interface. In-Reply-To: (Hao Xiang's message of "Wed, 28 Feb 2024 10:36:19 -0800") References: <20240226195654.934709-1-hao.xiang@bytedance.com> <20240226195654.934709-7-hao.xiang@bytedance.com> <87wmqozzjn.fsf@pond.sub.org> Date: Thu, 29 Feb 2024 07:01:12 +0100 Message-ID: <875xy7u7vb.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.102, 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, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Hao Xiang writes: > On Wed, Feb 28, 2024 at 1:52=E2=80=AFAM Markus Armbruster wrote: >> >> Hao Xiang writes: >> >> > This change extends the MigrationStatus interface to track zero pages >> > and zero bytes counter. >> > >> > Signed-off-by: Hao Xiang >> >> [...] >> >> > diff --git a/qapi/migration.json b/qapi/migration.json >> > index a0a85a0312..171734c07e 100644 >> > --- a/qapi/migration.json >> > +++ b/qapi/migration.json >> > @@ -63,6 +63,10 @@ >> > # between 0 and @dirty-sync-count * @multifd-channels. (since >> > # 7.1) >> > # >> > +# @zero-pages: number of zero pages (since 9.0) >> > +# >> > +# @zero-bytes: number of zero bytes sent (since 9.0) >> > +# >> >> Awfully terse. How are these two related? > > Sorry I forgot to address the same feedback from the last version. Happens :) > zero-pages are the number of pages being detected as all "zero" and > hence the payload isn't sent over the network. zero-bytes is basically > zero-pages * page_size. It's the number of bytes migrated (but not > actually sent through the network) because they are all "zero". These > two are related to the existing interface below. normal and > normal-bytes are the same representation of pages who are not all > "zero" and are actually sent through the network. > > # @normal: number of normal pages (since 1.2) > # > # @normal-bytes: number of normal bytes sent (since 1.2) We also have # @duplicate: number of duplicate (zero) pages (since 1.2) # # @skipped: number of skipped zero pages. Always zero, only provided for # compatibility (since 1.5) Page skipping was introduced in 1.5, and withdrawn in 1.5.3 and 1.6. @skipped was formally deprecated in 8.1. It'll soon be gone, no need to worry about it now. That leaves three values related to pages sent: @normal (and @normal-bytes), @duplicate (but no @duplicate-bytes), and @zero-pages (and @zero-bytes). I unwittingly created a naming inconsistency between @normal, @duplicate, and @zero-pages when I asked you to rename @zero to @zero-pages. The meaning of the three values is not obvious, and the doc comments don't explain them. Can you, or anybody familiar with migration, explain them to me? MigrationStats return some values as bytes, some as pages, and some as both. I hate that. Can we standardize on bytes? >> >> > # Features: >> > # >> > # @deprecated: Member @skipped is always zero since 1.5.3 >> >> [...] >>