From nobody Fri May 17 22:51:31 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1598964820; cv=none; d=zohomail.com; s=zohoarc; b=UvQwITEW+3mq1TtsSXRaBfeajkHEUw9svAZsTBNebb395uI5m4Nlm467YrIEgLQDMiZn6tmIGDnS/m34j/DKaFgXJtJVh6/ytMj/ZZoQlLmN8dVpY/0qfwR7ZZ/w0KunGDgKyZutxsaaFCIq8wIdYhg9df6Ja60rtBs3ToLijDY= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1598964820; h=Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:Sender:Subject:To; bh=7AGGthQ1ivLY8jUFPKCkOlK54RcKHsp2NYoB5SoCo0w=; b=OBqfW/z2SgdOvYVFy7hJ1zq+5NyXYC7oatlDBY4djBLQaDicACPJOu/32qwaF+mSD3f2cSiNeWnhd6dxWZtk057V/85JJaXxiF1Hw99HuqidkZmbWUVgTHWjV5/4u7819qbYvhT2fwI5+KVVLhpg47Gm9L0jXEK1s31B5wf/t1o= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1598964820443451.5242763926108; Tue, 1 Sep 2020 05:53:40 -0700 (PDT) Received: from localhost ([::1]:38144 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kD5n9-00032p-Lr for importer@patchew.org; Tue, 01 Sep 2020 08:53:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35212) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kD5lK-0008Mo-Ov for qemu-devel@nongnu.org; Tue, 01 Sep 2020 08:51:46 -0400 Received: from kerio.kamp.de ([195.62.97.192]:60820) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kD5lI-00026E-Hy for qemu-devel@nongnu.org; Tue, 01 Sep 2020 08:51:46 -0400 Received: from submission.kamp.de ([195.62.97.28]) by kerio.kamp.de with ESMTPS (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256 bits)) for qemu-devel@nongnu.org; Tue, 1 Sep 2020 14:51:27 +0200 Received: (qmail 58193 invoked from network); 1 Sep 2020 12:51:34 -0000 Received: from lieven-pc.kamp-intra.net (HELO lieven-pc) (relay@kamp.de@::ffff:172.21.12.60) by submission.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted) ESMTPA; 1 Sep 2020 12:51:34 -0000 Received: by lieven-pc (Postfix, from userid 1060) id 3D33413D866; Tue, 1 Sep 2020 14:51:34 +0200 (CEST) X-Footer: a2FtcC5kZQ== From: Peter Lieven To: qemu-devel@nongnu.org Subject: [PATCH] qemu-img: avoid unaligned read requests during convert Date: Tue, 1 Sep 2020 14:51:29 +0200 Message-Id: <20200901125129.6398-1-pl@kamp.de> X-Mailer: git-send-email 2.17.1 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=195.62.97.192; envelope-from=pl@kamp.de; helo=kerio.kamp.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/01 08:51:35 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: kwolf@redhat.com, Peter Lieven , qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" in case of large continous areas that share the same allocation status it happens that the value of s->sector_next_status is unaligned to the cluster size or even request alignment of the source. Avoid this by stripping down the s->sector_next_status position to cluster boundaries. Signed-off-by: Peter Lieven --- qemu-img.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/qemu-img.c b/qemu-img.c index 5308773811..ed17238c36 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1665,6 +1665,7 @@ enum ImgConvertBlockStatus { typedef struct ImgConvertState { BlockBackend **src; int64_t *src_sectors; + int *src_alignment; int src_num; int64_t total_sectors; int64_t allocated_sectors; @@ -1731,6 +1732,7 @@ static int convert_iteration_sectors(ImgConvertState = *s, int64_t sector_num) if (s->sector_next_status <=3D sector_num) { uint64_t offset =3D (sector_num - src_cur_offset) * BDRV_SECTOR_SI= ZE; int64_t count; + int tail; =20 do { count =3D n * BDRV_SECTOR_SIZE; @@ -1769,6 +1771,16 @@ static int convert_iteration_sectors(ImgConvertState= *s, int64_t sector_num) =20 n =3D DIV_ROUND_UP(count, BDRV_SECTOR_SIZE); =20 + /* + * Avoid that s->sector_next_status becomes unaligned to the source + * request alignment and/or cluster size to avoid unnecessary read + * cycles. + */ + tail =3D (sector_num - src_cur_offset + n) % s->src_alignment[src_= cur]; + if (n > tail) { + n -=3D tail; + } + if (ret & BDRV_BLOCK_ZERO) { s->status =3D post_backing_zero ? BLK_BACKING_FILE : BLK_ZERO; } else if (ret & BDRV_BLOCK_DATA) { @@ -2407,8 +2419,10 @@ static int img_convert(int argc, char **argv) =20 s.src =3D g_new0(BlockBackend *, s.src_num); s.src_sectors =3D g_new(int64_t, s.src_num); + s.src_alignment =3D g_new(int, s.src_num); =20 for (bs_i =3D 0; bs_i < s.src_num; bs_i++) { + BlockDriverState *src_bs; s.src[bs_i] =3D img_open(image_opts, argv[optind + bs_i], fmt, src_flags, src_writethrough, s.quiet, force_share); @@ -2423,6 +2437,13 @@ static int img_convert(int argc, char **argv) ret =3D -1; goto out; } + src_bs =3D blk_bs(s.src[bs_i]); + s.src_alignment[bs_i] =3D DIV_ROUND_UP(src_bs->bl.request_alignmen= t, + BDRV_SECTOR_SIZE); + if (!bdrv_get_info(src_bs, &bdi)) { + s.src_alignment[bs_i] =3D MAX(s.src_alignment[bs_i], + bdi.cluster_size / BDRV_SECTOR_SIZ= E); + } s.total_sectors +=3D s.src_sectors[bs_i]; } =20 @@ -2704,6 +2725,7 @@ out: g_free(s.src); } g_free(s.src_sectors); + g_free(s.src_alignment); fail_getopt: g_free(options); =20 --=20 2.17.1