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 13968C43334 for ; Tue, 5 Jul 2022 04:16:02 +0000 (UTC) Received: from localhost ([::1]:51594 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o8Zyj-0006Ru-O4 for qemu-devel@archiver.kernel.org; Tue, 05 Jul 2022 00:16:01 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55342) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o8ZxA-0004w7-7x for qemu-devel@nongnu.org; Tue, 05 Jul 2022 00:14:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:27710) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o8Zx6-0001uJ-V9 for qemu-devel@nongnu.org; Tue, 05 Jul 2022 00:14:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656994459; 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=tiiaeLQXQIsHhmZtkqhyKTSgi3R8keRv4xeWaIFoS94=; b=A0V0zOc2yRME0/eWGGliHGgtUzbeQcGKtmaJRu8uZeYTR3os94z0pUjV7/0k/d7Bbx7LPV nFY194SJJoAmiiSaDmZLKRXFTtBLka1zjtBbYKD7RfYwVsXHDjkgPIoed9QbfIEIL4DosK 6u2zE+GB8IqhXBkVEKkkW67mwJKv5H4= 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-466-YMGmQpcPM5G4zuZ_X1tzfg-1; Tue, 05 Jul 2022 00:14:16 -0400 X-MC-Unique: YMGmQpcPM5G4zuZ_X1tzfg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AE76C3C0CD39 for ; Tue, 5 Jul 2022 04:14:16 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.195.112]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 73D0C4010FA6; Tue, 5 Jul 2022 04:14:16 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 3C76E21E690D; Tue, 5 Jul 2022 06:14:15 +0200 (CEST) From: Markus Armbruster To: Leonardo =?utf-8?Q?Br=C3=A1s?= Cc: "Daniel P." =?utf-8?Q?Berrang=C3=A9?= , Markus Armbruster , "Dr. David Alan Gilbert" , Juan Quintela , Eric Blake , Peter Xu , qemu-devel@nongnu.org Subject: Re: [PATCH v2 2/3] Add zero-copy-copied migration stat References: <20220701155935.482503-1-leobras@redhat.com> <20220701155935.482503-3-leobras@redhat.com> <877d4tz9gx.fsf@pond.sub.org> <87k08tw0bq.fsf@pond.sub.org> <87czelvxrt.fsf@pond.sub.org> <97f75348557212d32bb38c20b6800208219e4aa8.camel@redhat.com> Date: Tue, 05 Jul 2022 06:14:15 +0200 In-Reply-To: <97f75348557212d32bb38c20b6800208219e4aa8.camel@redhat.com> ("Leonardo =?utf-8?Q?Br=C3=A1s=22's?= message of "Mon, 04 Jul 2022 15:13:08 -0300") Message-ID: <87o7y4tcvc.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 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=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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" Leonardo Br=C3=A1s writes: > Thanks Daniel, Markus and Dave for the feedback! > > On Mon, 2022-07-04 at 14:14 +0100, Daniel P. Berrang=C3=A9 wrote: >> On Mon, Jul 04, 2022 at 02:59:50PM +0200, Markus Armbruster wrote: >> > Daniel P. Berrang=C3=A9 writes: >> >=20 >> > > On Mon, Jul 04, 2022 at 02:04:41PM +0200, Markus Armbruster wrote: >> >=20 > [...] > >>=20 >> since 7.1, unless you're planning for really tortuous review :) >>=20 > > Ok, updated :) > >> > [...] >> >=20 >> > > > Please rephrase the documentation of @zero-copy-copied in terms of >> > > > @dirty-sync-count.=C2=A0 Here's my attempt. >> > > >=20 >> > > > # @zero-copy-copied: Number of times dirty RAM synchronization cou= ld not >> > > > #=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 avoid copying zero page= s.=C2=A0 This is between 0 and >> > > > #=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 @dirty-sync-count.=C2= =A0 (since 7.1) > > That's a great description! And it's almost 100% correct. That's why we do patch review :) > IIUC dirty-sync-count increments on migration_bitmap_sync() once after ea= ch full > dirty-bitmap scan, and even with multifd syncing at the same point, it co= uld > potentially have a increment per multifd channel. > > The only change would be having: > # This is between 0 and @dirty-sync-count * @multifd-channel. Makes sense to me. [...]