From: Max Reitz <mreitz@redhat.com>
To: John Snow <jsnow@redhat.com>,
qemu-devel@nongnu.org, qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Fam Zheng <fam@euphon.net>,
vsementsov@virtuozzo.com, Wen Congyang <wencongyang2@huawei.com>,
Xie Changlong <xiechanglong.d@gmail.com>,
Markus Armbruster <armbru@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 05/12] hbitmap: enable merging across granularities
Date: Thu, 20 Jun 2019 17:47:16 +0200 [thread overview]
Message-ID: <8f3822dc-b3a5-994a-6fd7-d7291954789c@redhat.com> (raw)
In-Reply-To: <20190620010356.19164-6-jsnow@redhat.com>
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On 20.06.19 03:03, John Snow wrote:
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
> util/hbitmap.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/util/hbitmap.c b/util/hbitmap.c
> index 45d1725daf..0d6724b7bc 100644
> --- a/util/hbitmap.c
> +++ b/util/hbitmap.c
> @@ -777,7 +777,17 @@ void hbitmap_truncate(HBitmap *hb, uint64_t size)
>
> bool hbitmap_can_merge(const HBitmap *a, const HBitmap *b)
> {
> - return (a->size == b->size) && (a->granularity == b->granularity);
> + return (a->size == b->size);
> +}
> +
> +static void hbitmap_sparse_merge(HBitmap *dst, const HBitmap *src)
> +{
> + uint64_t offset = 0;
> + uint64_t count = src->orig_size;
> +
> + while (hbitmap_next_dirty_area(src, &offset, &count)) {
> + hbitmap_set(dst, offset, count);
> + }
> }
>
> /**
> @@ -804,6 +814,16 @@ bool hbitmap_merge(const HBitmap *a, const HBitmap *b, HBitmap *result)
> return true;
> }
>
> + if (a->size != b->size) {
Don’t you mean s/size/granularity/?
Right now, this is dead code, which leads me to asking for a test.
(Well, no, I would’ve asked anyway.)
Max
> + if (a != result) {
> + hbitmap_sparse_merge(result, a);
> + }
> + if (b != result) {
> + hbitmap_sparse_merge(result, b);
> + }
> + return true;
> + }
> +
> /* This merge is O(size), as BITS_PER_LONG and HBITMAP_LEVELS are constant.
> * It may be possible to improve running times for sparsely populated maps
> * by using hbitmap_iter_next, but this is suboptimal for dense maps.
>
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next prev parent reply other threads:[~2019-06-20 16:04 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-20 1:03 [Qemu-devel] [PATCH 00/12] bitmaps: introduce 'bitmap' sync mode John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 01/12] qapi: add BitmapSyncMode enum John Snow
2019-06-20 14:21 ` Max Reitz
2019-06-20 1:03 ` [Qemu-devel] [PATCH 02/12] block/backup: Add mirror sync mode 'bitmap' John Snow
2019-06-20 15:00 ` Max Reitz
2019-06-20 16:01 ` John Snow
2019-06-20 18:46 ` Max Reitz
2019-06-21 11:29 ` Vladimir Sementsov-Ogievskiy
2019-06-21 19:39 ` John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 03/12] block/backup: add 'never' policy to bitmap sync mode John Snow
2019-06-20 15:25 ` Max Reitz
2019-06-20 16:11 ` John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 04/12] hbitmap: Fix merge when b is empty, and result is not an alias of a John Snow
2019-06-20 15:39 ` Max Reitz
2019-06-20 16:13 ` John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 05/12] hbitmap: enable merging across granularities John Snow
2019-06-20 15:47 ` Max Reitz [this message]
2019-06-20 18:13 ` John Snow
2019-06-20 16:47 ` Max Reitz
2019-06-21 11:45 ` Vladimir Sementsov-Ogievskiy
2019-06-21 11:41 ` Vladimir Sementsov-Ogievskiy
2019-06-20 1:03 ` [Qemu-devel] [PATCH 06/12] block/dirty-bitmap: add bdrv_dirty_bitmap_claim John Snow
2019-06-20 16:02 ` Max Reitz
2019-06-20 16:36 ` John Snow
2019-06-21 11:58 ` Vladimir Sementsov-Ogievskiy
2019-06-21 21:34 ` John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 07/12] block/backup: add 'always' bitmap sync policy John Snow
2019-06-20 17:00 ` Max Reitz
2019-06-20 18:44 ` John Snow
2019-06-20 18:53 ` Max Reitz
2019-06-21 12:57 ` Vladimir Sementsov-Ogievskiy
2019-06-21 12:59 ` Vladimir Sementsov-Ogievskiy
2019-06-21 13:08 ` Vladimir Sementsov-Ogievskiy
2019-06-21 13:44 ` Vladimir Sementsov-Ogievskiy
2019-06-21 20:58 ` John Snow
2019-06-21 21:48 ` Max Reitz
2019-06-21 22:52 ` John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 08/12] iotests: add testing shim for script-style python tests John Snow
2019-06-20 17:09 ` Max Reitz
2019-06-20 17:26 ` Max Reitz
2019-06-20 18:47 ` John Snow
2019-06-20 18:55 ` Max Reitz
2019-06-20 1:03 ` [Qemu-devel] [PATCH 09/12] iotests: teach run_job to cancel pending jobs John Snow
2019-06-20 17:17 ` Max Reitz
2019-06-20 1:03 ` [Qemu-devel] [PATCH 10/12] iotests: teach FilePath to produce multiple paths John Snow
2019-06-20 17:22 ` Max Reitz
2019-06-20 1:03 ` [Qemu-devel] [PATCH 11/12] iotests: add test 257 for bitmap-mode backups John Snow
2019-06-20 18:35 ` Max Reitz
2019-06-20 19:08 ` John Snow
2019-06-20 19:48 ` Max Reitz
2019-06-20 19:59 ` John Snow
2019-06-20 1:03 ` [Qemu-devel] [PATCH 12/12] block/backup: loosen restriction on readonly bitmaps John Snow
2019-06-20 18:37 ` Max Reitz
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