{"id":815094,"url":"http://patchwork.ozlabs.org/api/1.2/patches/815094/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170918185819.5984-8-eblake@redhat.com/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.2/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170918185819.5984-8-eblake@redhat.com>","list_archive_url":null,"date":"2017-09-18T18:58:06","name":"[v8,07/20] dirty-bitmap: Track bitmap size by bytes","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"6f45d7bdb6957e1c87f33080de83708d1e2ad91e","submitter":{"id":6591,"url":"http://patchwork.ozlabs.org/api/1.2/people/6591/?format=json","name":"Eric Blake","email":"eblake@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170918185819.5984-8-eblake@redhat.com/mbox/","series":[{"id":3711,"url":"http://patchwork.ozlabs.org/api/1.2/series/3711/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=3711","date":"2017-09-18T18:58:00","name":"make dirty-bitmap byte-based","version":8,"mbox":"http://patchwork.ozlabs.org/series/3711/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/815094/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/815094/checks/","tags":{},"related":[],"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-mx04.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx04.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=eblake@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 3xwwSb1DyQz9s3T\n\tfor ;\n\tTue, 19 Sep 2017 05:05:35 +1000 (AEST)","from localhost ([::1]:38384 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1du1ML-0000Yr-0U\n\tfor incoming@patchwork.ozlabs.org; Mon, 18 Sep 2017 15:05:33 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:44232)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1du1Fo-00029m-QX\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 14:58:52 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1du1Fn-0006R9-JL\n\tfor qemu-devel@nongnu.org; Mon, 18 Sep 2017 14:58:48 -0400","from mx1.redhat.com ([209.132.183.28]:57513)\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 1du1Fk-0006Ot-PI; Mon, 18 Sep 2017 14:58:44 -0400","from smtp.corp.redhat.com\n\t(int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16])\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 BFF017EA9F;\n\tMon, 18 Sep 2017 18:58:43 +0000 (UTC)","from red.redhat.com (ovpn-124-97.rdu2.redhat.com [10.10.124.97])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 70B745C1A3;\n\tMon, 18 Sep 2017 18:58:40 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com BFF017EA9F","From":"Eric Blake ","To":"qemu-devel@nongnu.org","Date":"Mon, 18 Sep 2017 13:58:06 -0500","Message-Id":"<20170918185819.5984-8-eblake@redhat.com>","In-Reply-To":"<20170918185819.5984-1-eblake@redhat.com>","References":"<20170918185819.5984-1-eblake@redhat.com>","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.16","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.28]);\n\tMon, 18 Sep 2017 18:58:43 +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":"[Qemu-devel] [PATCH v8 07/20] dirty-bitmap: Track bitmap size by\n\tbytes","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 , jsnow@redhat.com","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"},"content":"We are still using an internal hbitmap that tracks a size in sectors,\nwith the granularity scaled down accordingly, because it lets us\nuse a shortcut for our iterators which are currently sector-based.\nBut there's no reason we can't track the dirty bitmap size in bytes,\nsince it is (mostly) an internal-only variable (remember, the size\nis how many bytes are covered by the bitmap, not how many bytes the\nbitmap occupies). A later cleanup will convert dirty bitmap\ninternals to be entirely byte-based, eliminating the intermediate\nsector rounding added here; and technically, since bdrv_getlength()\nalready rounds up to sectors, our use of DIV_ROUND_UP is more for\ntheoretical completeness than for any actual rounding.\n\nUse is_power_of_2() while at it, instead of open-coding that.\n\nSigned-off-by: Eric Blake \nReviewed-by: John Snow \n\n---\nv8: rebase to earlier truncate changes, R-b kept\nv7: split external from internal [Kevin], drop R-b\nv6: no change\nv5: fix bdrv_dirty_bitmap_truncate [John], drop R-b\nv4: retitle from \"Track size in bytes\", rebase to persistent bitmaps,\nround up when converting bytes to sectors\nv3: no change\nv2: tweak commit message, no code change\n---\n block/dirty-bitmap.c | 26 ++++++++++++++------------\n 1 file changed, 14 insertions(+), 12 deletions(-)","diff":"diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c\nindex 755555af32..6d32554b4e 100644\n--- a/block/dirty-bitmap.c\n+++ b/block/dirty-bitmap.c\n@@ -42,7 +42,7 @@ struct BdrvDirtyBitmap {\n HBitmap *meta; /* Meta dirty bitmap */\n BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */\n char *name; /* Optional non-empty unique ID */\n- int64_t size; /* Size of the bitmap (Number of sectors) */\n+ int64_t size; /* Size of the bitmap, in bytes */\n bool disabled; /* Bitmap is disabled. It ignores all writes to\n the device */\n int active_iterators; /* How many iterators are active */\n@@ -115,17 +115,14 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,\n {\n int64_t bitmap_size;\n BdrvDirtyBitmap *bitmap;\n- uint32_t sector_granularity;\n\n- assert((granularity & (granularity - 1)) == 0);\n+ assert(is_power_of_2(granularity) && granularity >= BDRV_SECTOR_SIZE);\n\n if (name && bdrv_find_dirty_bitmap(bs, name)) {\n error_setg(errp, \"Bitmap already exists: %s\", name);\n return NULL;\n }\n- sector_granularity = granularity >> BDRV_SECTOR_BITS;\n- assert(sector_granularity);\n- bitmap_size = bdrv_nb_sectors(bs);\n+ bitmap_size = bdrv_getlength(bs);\n if (bitmap_size < 0) {\n error_setg_errno(errp, -bitmap_size, \"could not get length of device\");\n errno = -bitmap_size;\n@@ -133,7 +130,12 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,\n }\n bitmap = g_new0(BdrvDirtyBitmap, 1);\n bitmap->mutex = &bs->dirty_bitmap_mutex;\n- bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));\n+ /*\n+ * TODO - let hbitmap track full granularity. For now, it is tracking\n+ * only sector granularity, as a shortcut for our iterators.\n+ */\n+ bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap_size, BDRV_SECTOR_SIZE),\n+ ctz32(granularity) - BDRV_SECTOR_BITS);\n bitmap->size = bitmap_size;\n bitmap->name = g_strdup(name);\n bitmap->disabled = false;\n@@ -175,7 +177,7 @@ void bdrv_release_meta_dirty_bitmap(BdrvDirtyBitmap *bitmap)\n\n int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap)\n {\n- return bitmap->size * BDRV_SECTOR_SIZE;\n+ return bitmap->size;\n }\n\n const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap)\n@@ -305,14 +307,13 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,\n void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes)\n {\n BdrvDirtyBitmap *bitmap;\n- int64_t size = DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE);\n\n bdrv_dirty_bitmaps_lock(bs);\n QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {\n assert(!bdrv_dirty_bitmap_frozen(bitmap));\n assert(!bitmap->active_iterators);\n- hbitmap_truncate(bitmap->bitmap, size);\n- bitmap->size = size;\n+ hbitmap_truncate(bitmap->bitmap, DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE));\n+ bitmap->size = bytes;\n }\n bdrv_dirty_bitmaps_unlock(bs);\n }\n@@ -549,7 +550,8 @@ void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)\n hbitmap_reset_all(bitmap->bitmap);\n } else {\n HBitmap *backup = bitmap->bitmap;\n- bitmap->bitmap = hbitmap_alloc(bitmap->size,\n+ bitmap->bitmap = hbitmap_alloc(DIV_ROUND_UP(bitmap->size,\n+ BDRV_SECTOR_SIZE),\n hbitmap_granularity(backup));\n *out = backup;\n }\n","prefixes":["v8","07/20"]}