From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, mreitz@redhat.com, kwolf@redhat.com,
den@openvz.org
Subject: Re: [PATCH v6 00/12] qcow2: fix parallel rewrite and discard (lockless)
Date: Mon, 26 Apr 2021 15:15:01 +0300 [thread overview]
Message-ID: <2514921e-e423-6def-dfdc-93df9d80e41a@virtuozzo.com> (raw)
In-Reply-To: <20210422163046.442932-1-vsementsov@virtuozzo.com>
22.04.2021 19:30, Vladimir Sementsov-Ogievskiy wrote:
> Hi all!
>
> It's an alternative lock-less solution to
> [PATCH v4 0/3] qcow2: fix parallel rewrite and discard (rw-lock)
>
> In v6 a lot of things are rewritten.
>
> What is changed:
>
> 1. rename the feature to host_range_refcnt, move it to separate file
> 2. better naming for everything (I hope)
> 3. cover reads, not only writes
> 4. do "ref" in qcow2_get_host_offset(), qcow2_alloc_host_offset(),
> qcow2_alloc_compressed_cluster_offset().
> and callers do "unref" appropriately.
>
About performance. With these series we do extra allocations and hash-map operations.. Still testing by
./build/qemu-img bench -c 1000000 -s 4K --image-opts driver=null-co,size=5G
and
./build/qemu-img bench -c 1000000 -s 4K -w --image-opts driver=null-co,size=5G
I see difference less than 1%.
--
Best regards,
Vladimir
next prev parent reply other threads:[~2021-04-26 12:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 16:30 [PATCH v6 00/12] qcow2: fix parallel rewrite and discard (lockless) Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 01/12] iotests: add qcow2-discard-during-rewrite Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 02/12] qcow2: fix cache discarding in update_refcount() Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 03/12] block/qcow2-cluster: assert no data_file on compressed write path Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 04/12] block/qcow2-refcount: rename and publish update_refcount_discard() Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 05/12] block/qcow2: introduce qcow2_parse_compressed_cluster_descriptor() Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 06/12] block/qcow2: refactor qcow2_co_preadv_task() to have one return Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 07/12] block/qcow2: qcow2_co_pwrite_zeroes: use QEMU_LOCK_GUARD Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 08/12] qcow2: introduce is_cluster_free() helper Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 09/12] qcow2: introduce host-range-refs Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 10/12] qcow2: introduce qcow2_host_cluster_postponed_discard() Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 11/12] qcow2: protect data writing by host range reference Vladimir Sementsov-Ogievskiy
2021-04-22 16:30 ` [PATCH v6 12/12] qcow2: protect data reading " Vladimir Sementsov-Ogievskiy
2021-04-26 12:15 ` Vladimir Sementsov-Ogievskiy [this message]
2021-05-10 13:07 ` [PATCH v6 00/12] qcow2: fix parallel rewrite and discard (lockless) Vladimir Sementsov-Ogievskiy
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