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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC46FC432C0 for ; Mon, 25 Nov 2019 12:31:24 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A79022082F for ; Mon, 25 Nov 2019 12:31:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="V3i1izOo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A79022082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43016 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iZDWV-00016g-LE for qemu-devel@archiver.kernel.org; Mon, 25 Nov 2019 07:31:23 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59525) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iZDNC-00007E-Al for qemu-devel@nongnu.org; Mon, 25 Nov 2019 07:21:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iZDNA-0000bt-FQ for qemu-devel@nongnu.org; Mon, 25 Nov 2019 07:21:46 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:49524 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iZDN8-0000aL-Mc for qemu-devel@nongnu.org; Mon, 25 Nov 2019 07:21:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574684502; 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:autocrypt:autocrypt; bh=m2bKZgh21qPmLIeEXnnceEm5+4m2Fui7uXCrCcuZj0k=; b=V3i1izOoxucT9chEyhQmFqpvVf75TEhkX5NXtDLg4LhUfvOTHnqL/NcNEUuXFLKAtqwC+s hUZpBKGldZyEkaJ5M0gEPAG9MrHpYOru3g+gysuFQnSeVy5yoAKC+DFG5liO3eUQkIUwaE 7bsSpy6F3OcDDqcQiTNPOjihdS4AU2w= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-293-xWAh3EatPFyirj6hiSB_OQ-1; Mon, 25 Nov 2019 07:21:40 -0500 X-MC-Unique: xWAh3EatPFyirj6hiSB_OQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 70EFD801E61; Mon, 25 Nov 2019 12:21:39 +0000 (UTC) Received: from dresden.str.redhat.com (unknown [10.40.205.102]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 15CE35C1D4; Mon, 25 Nov 2019 12:21:33 +0000 (UTC) Subject: Re: [PATCH for-4.2? v3 0/8] block: Fix resize (extending) of short overlays To: Eric Blake , Peter Maydell , Kevin Wolf References: <20191122160511.8377-1-kwolf@redhat.com> <713adac7-b997-6723-6b07-f527d0b804ac@redhat.com> From: Max Reitz Autocrypt: addr=mreitz@redhat.com; prefer-encrypt=mutual; keydata= mQENBFXOJlcBCADEyyhOTsoa/2ujoTRAJj4MKA21dkxxELVj3cuILpLTmtachWj7QW+TVG8U /PsMCFbpwsQR7oEy8eHHZwuGQsNpEtNC2G/L8Yka0BIBzv7dEgrPzIu+W3anZXQW4702+uES U29G8TP/NGfXRRHGlbBIH9KNUnOSUD2vRtpOLXkWsV5CN6vQFYgQfFvmp5ZpPeUe6xNplu8V mcTw8OSEDW/ZnxJc8TekCKZSpdzYoxfzjm7xGmZqB18VFwgJZlIibt1HE0EB4w5GsD7x5ekh awIe3RwoZgZDLQMdOitJ1tUc8aqaxvgA4tz6J6st8D8pS//m1gAoYJWGwwIVj1DjTYLtABEB AAG0HU1heCBSZWl0eiA8bXJlaXR6QHJlZGhhdC5jb20+iQFTBBMBCAA9AhsDBQkSzAMABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheABQJVzie5FRhoa3A6Ly9rZXlzLmdudXBnLm5ldAAKCRD0 B9sAYdXPQDcIB/9uNkbYEex1rHKz3mr12uxYMwLOOFY9fstP5aoVJQ1nWQVB6m2cfKGdcRe1 2/nFaHSNAzT0NnKz2MjhZVmcrpyd2Gp2QyISCfb1FbT82GMtXFj1wiHmPb3CixYmWGQUUh+I AvUqsevLA+WihgBUyaJq/vuDVM1/K9Un+w+Tz5vpeMidlIsTYhcsMhn0L9wlCjoucljvbDy/ 8C9L2DUdgi3XTa0ORKeflUhdL4gucWoAMrKX2nmPjBMKLgU7WLBc8AtV+84b9OWFML6NEyo4 4cP7cM/07VlJK53pqNg5cHtnWwjHcbpGkQvx6RUx6F1My3y52vM24rNUA3+ligVEgPYBuQEN BFXOJlcBCADAmcVUNTWT6yLWQHvxZ0o47KCP8OcLqD+67T0RCe6d0LP8GsWtrJdeDIQk+T+F xO7DolQPS6iQ6Ak2/lJaPX8L0BkEAiMuLCKFU6Bn3lFOkrQeKp3u05wCSV1iKnhg0UPji9V2 W5eNfy8F4ZQHpeGUGy+liGXlxqkeRVhLyevUqfU0WgNqAJpfhHSGpBgihUupmyUg7lfUPeRM DzAN1pIqoFuxnN+BRHdAecpsLcbR8sQddXmDg9BpSKozO/JyBmaS1RlquI8HERQoe6EynJhd 64aICHDfj61rp+/0jTIcevxIIAzW70IadoS/y3DVIkuhncgDBvGbF3aBtjrJVP+5ABEBAAGJ ASUEGAEIAA8FAlXOJlcCGwwFCRLMAwAACgkQ9AfbAGHVz0CbFwf9F/PXxQR9i4N0iipISYjU sxVdjJOM2TMut+ZZcQ6NSMvhZ0ogQxJ+iEQ5OjnIputKvPVd5U7WRh+4lF1lB/NQGrGZQ1ic alkj6ocscQyFwfib+xIe9w8TG1CVGkII7+TbS5pXHRxZH1niaRpoi/hYtgzkuOPp35jJyqT/ /ELbqQTDAWcqtJhzxKLE/ugcOMK520dJDeb6x2xVES+S5LXby0D4juZlvUj+1fwZu+7Io5+B bkhSVPb/QdOVTpnz7zWNyNw+OONo1aBUKkhq2UIByYXgORPFnbfMY7QWHcjpBVw9MgC4tGeF R4bv+1nAMMxKmb5VvQCExr0eFhJUAHAhVg== Message-ID: <0b865e2b-2318-2d14-2674-d33f84e05f65@redhat.com> Date: Mon, 25 Nov 2019 13:21:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <713adac7-b997-6723-6b07-f527d0b804ac@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="sXF6L5wLfezWlathVnFjFO0K1haYCzys0" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Qemu-block , Vladimir Sementsov-Ogievskiy , QEMU Developers , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --sXF6L5wLfezWlathVnFjFO0K1haYCzys0 Content-Type: multipart/mixed; boundary="VGJHFxBOlfZQj0a7WJKWH5O3F4PrMNekc" --VGJHFxBOlfZQj0a7WJKWH5O3F4PrMNekc Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 22.11.19 17:41, Eric Blake wrote: > On 11/22/19 10:17 AM, Peter Maydell wrote: [...] >> Eyeballing of the diffstat plus the fact we're on v4 of >> the patchset already makes me a little uneasy about >> putting it into rc3, but if the bug we're fixing matters >> enough we can do it. >=20 > In terms of diffstat, the v3 series was much smaller in impact.=C2=A0 Bot= h > versions add robustness, where the difference between v3 and v4 is > whether we introduce a speed penalty on an unlikely setup (v3) or reject > any operation where it would require a speed penalty to avoid data > problems (v4). I=E2=80=99d just like to add that this isn=E2=80=99t just about a speed pen= alty, but about the fact that the monitor is blocked while the operation is running. So the speed penalty has more impact than just some background operation being slow. Max --VGJHFxBOlfZQj0a7WJKWH5O3F4PrMNekc-- --sXF6L5wLfezWlathVnFjFO0K1haYCzys0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl3bx0wACgkQ9AfbAGHV z0ATJgf+Oac7gxHyGxoBUdcpNkD/kSUy0ztl8S/9Q+p3QSBGeX/DTDDTkYI45WP6 JqaHkm1nhjJC8OYPyqL3sOgKP9WqOGZcTLgTekz2HtGJNJmCYbaOlrp7Z3ty3Zto uisZob14pjuLyFl5gwAgXTKIN17zrCSys/ZbvdKhR2gEEcSyqzB0oZ0cQXp/Fz1Z NDkl2Y2NDL/8EutdmJw6oyPP8ylEsTnxEeDMzXa0GzVjQNSV3shPizC6AokZ47Ug Lucel/HQD0HwAjkgz8S/C9dfMo+Bcxfn+XLJsu2RlfddVwWaulSuznp6I7w9V0Sc nsKd4j68J45eQtDkNBE/mWHkCfGBHA== =IBQK -----END PGP SIGNATURE----- --sXF6L5wLfezWlathVnFjFO0K1haYCzys0--