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 21F5FC369DC for ; Thu, 1 May 2025 17:22:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uAXaq-00056Y-FN; Thu, 01 May 2025 13:21:04 -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 1uAXan-00054C-IP for qemu-devel@nongnu.org; Thu, 01 May 2025 13:21:01 -0400 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 1uAXal-0003Ga-R9 for qemu-devel@nongnu.org; Thu, 01 May 2025 13:21:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1746120058; 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=xX/JiV5ZiaxXa8afLFouH+B5J8JazaLmEUfNHqYmtCQ=; b=GBUmdttDTrP8Bd6rcCbFxBzTBlAfr0AB78ZEsjgPXKjq3t2+Afgs92xEv6Wb70TsXqsVAa buNLjsm8hca5F24HqpbH6aShcHTSxzEw6vDCZmOQnSmnxrKBJ1Qhc3f7QOdJg5MMouqYXr lMKGnM7Ju4r0mF4fBChnjXAttAroEU4= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-652-52DgaLfSOKSQBiVKM5wcMg-1; Thu, 01 May 2025 13:20:55 -0400 X-MC-Unique: 52DgaLfSOKSQBiVKM5wcMg-1 X-Mimecast-MFC-AGG-ID: 52DgaLfSOKSQBiVKM5wcMg_1746120054 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3CE1F195608C; Thu, 1 May 2025 17:20:53 +0000 (UTC) Received: from localhost (unknown [10.2.16.99]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id DF22019560A3; Thu, 1 May 2025 17:20:51 +0000 (UTC) Date: Thu, 1 May 2025 13:20:50 -0400 From: Stefan Hajnoczi To: Eric Blake Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, vsementsov@yandex-team.ru, Fam Zheng , Kevin Wolf , Hanna Reitz Subject: Re: [PATCH v3 03/11] block: Let bdrv_co_is_zero_fast consolidate adjacent extents Message-ID: <20250501172050.GD99177@fedora> References: <20250425005439.2252467-13-eblake@redhat.com> <20250425005439.2252467-16-eblake@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="7kP80jPhCPqWlwMS" Content-Disposition: inline In-Reply-To: <20250425005439.2252467-16-eblake@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.644, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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 --7kP80jPhCPqWlwMS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Apr 24, 2025 at 07:52:03PM -0500, Eric Blake wrote: > Some BDS drivers have a cap on how much block status they can supply > in one query (for example, NBD talking to an older server cannot > inspect more than 4G per query; and qcow2 tends to cap its answers > rather than cross a cluster boundary of an L1 table). Although the > existing callers of bdrv_co_is_zero_fast are not passing in that large > of a 'bytes' parameter, an upcoming caller wants to query the entire > image at once, and will thus benefit from being able to treat adjacent > zero regions in a coalesced manner, rather than claiming the region is > non-zero merely because pnum was truncated and didn't match the > incoming bytes. >=20 > While refactoring this into a loop, note that there is no need to > assign pnum prior to calling bdrv_co_common_block_status_above() (it > is guaranteed to be assigned deeper in the callstack). >=20 > Signed-off-by: Eric Blake >=20 > --- >=20 > v3: also tweak function comment > --- > block/io.c | 29 ++++++++++++++++------------- > 1 file changed, 16 insertions(+), 13 deletions(-) Reviewed-by: Stefan Hajnoczi --7kP80jPhCPqWlwMS Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmgTrXIACgkQnKSrs4Gr c8hh3wgAuf0N4eGwZqA5O1aNVDN04Gp16u3Vnh9hqOpUjD1nG4kSV5aoS78nf6tR 2Jk746FbffeYvHI0ccRqGLaOgn0dt7IU0eo17t6gHqUh0UEXL/LWhNqLdGwOTVqy 16j5lGfyBgEpTHxCdBqepgCgYh+wIQjbn9kLHoJui/xc9jzfDe5dv6Ltw7BrlBMc XDnRL/sWPmyQAnmnjbrFzf4Ctem0/a1f6DhJEI4++f1mfPGyAp3yH/dNAgfYoGTq wamK6L0M07a5IlfNDlTuiYbkEoHDN+jrH67kgHmxIIxcd3y0xjowX5z/bsTNgKT8 VBK7s4BZ9EGCWsz4qPELrS1F5TSqkA== =VrzU -----END PGP SIGNATURE----- --7kP80jPhCPqWlwMS--