[{"id":1768251,"web_url":"http://patchwork.ozlabs.org/comment/1768251/","msgid":"<91671a4e-e430-6954-6c0a-f2dc364ba3e7@redhat.com>","list_archive_url":null,"date":"2017-09-14T00:05:13","subject":"Re: [Qemu-devel] [PATCH v7 07/20] dirty-bitmap: Track bitmap size\n\tby bytes","submitter":{"id":64343,"url":"http://patchwork.ozlabs.org/api/people/64343/","name":"John Snow","email":"jsnow@redhat.com"},"content":"On 09/12/2017 04:31 PM, Eric Blake wrote:\n> We are still using an internal hbitmap that tracks a size in sectors,\n> with the granularity scaled down accordingly, because it lets us\n> use a shortcut for our iterators which are currently sector-based.\n> But there's no reason we can't track the dirty bitmap size in bytes,\n> since it is (mostly) an internal-only variable (remember, the size\n> is how many bytes are covered by the bitmap, not how many bytes the\n> bitmap occupies). A later cleanup will convert dirty bitmap\n> internals to be entirely byte-based, eliminating the intermediate\n> sector rounding added here; and technically, since bdrv_getlength()\n> already rounds up to sectors, our use of DIV_ROUND_UP is more for\n> theoretical completeness than for any actual rounding.\n> \n> Use is_power_of_2() while at it, instead of open-coding that.\n> \n> Signed-off-by: Eric Blake \n> \n\nReviewed-by: John Snow ","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","ext-mx02.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx02.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=jsnow@redhat.com"],"Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xszMh13Bkz9sRm\n\tfor ;\n\tThu, 14 Sep 2017 10:06:06 +1000 (AEST)","from localhost ([::1]:45112 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dsHfP-0005JT-Is\n\tfor incoming@patchwork.ozlabs.org; Wed, 13 Sep 2017 20:06:03 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:49294)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dsHel-0005IJ-LU\n\tfor qemu-devel@nongnu.org; Wed, 13 Sep 2017 20:05:24 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dsHek-0003UL-QZ\n\tfor qemu-devel@nongnu.org; Wed, 13 Sep 2017 20:05:23 -0400","from mx1.redhat.com ([209.132.183.28]:43262)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from )\n\tid 1dsHeg-0003Rb-Fm; Wed, 13 Sep 2017 20:05:18 -0400","from smtp.corp.redhat.com\n\t(int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id 2F0D78763C;\n\tThu, 14 Sep 2017 00:05:17 +0000 (UTC)","from [10.18.17.231] (dhcp-17-231.bos.redhat.com [10.18.17.231])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 0C3855D724;\n\tThu, 14 Sep 2017 00:05:13 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com 2F0D78763C","To":"Eric Blake , qemu-devel@nongnu.org","References":"<20170912203119.24166-1-eblake@redhat.com>\n\t<20170912203119.24166-8-eblake@redhat.com>","From":"John Snow ","Message-ID":"<91671a4e-e430-6954-6c0a-f2dc364ba3e7@redhat.com>","Date":"Wed, 13 Sep 2017 20:05:13 -0400","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101\n\tThunderbird/52.3.0","MIME-Version":"1.0","In-Reply-To":"<20170912203119.24166-8-eblake@redhat.com>","Content-Type":"text/plain; charset=utf-8","Content-Language":"en-US","Content-Transfer-Encoding":"7bit","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.14","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.26]);\n\tThu, 14 Sep 2017 00:05:17 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","Subject":"Re: [Qemu-devel] [PATCH v7 07/20] dirty-bitmap: Track bitmap size\n\tby bytes","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"kwolf@redhat.com, vsementsov@virtuozzo.com, Fam Zheng , \n\tqemu-block@nongnu.org, Max Reitz ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"}}]