From: "Denis V. Lunev" <den@openvz.org>
To: Peter Lieven <pl@kamp.de>
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v3 0/8] eliminate data write in bdrv_write_zeroes on Linux in raw-posix.c
Date: Tue, 30 Dec 2014 14:07:37 +0300 [thread overview]
Message-ID: <54A28779.20900@openvz.org> (raw)
In-Reply-To: <54A284A7.9060007@kamp.de>
On 30/12/14 13:55, Peter Lieven wrote:
> Am 30.12.2014 um 10:20 schrieb Denis V. Lunev:
>> These patches eliminate data writes completely on Linux if fallocate
>> FALLOC_FL_ZERO_RANGE or FALLOC_FL_PUNCH_HOLE are supported on
>> underlying filesystem.
>>
>> I have performed several tests with non-aligned fallocate calls and
>> in all cases (with non-aligned fallocates) Linux performs fine, i.e.
>> areas are zeroed correctly. Checks were made on
>> Linux 3.16.0-28-generic #38-Ubuntu SMP
>>
>> This should seriously increase performance in some special cases.
> Could you give a hint what that special cases are? It would help
> to evaluate and test the performance difference.
>
> Thanks,
> Peter
- 15% in Parallels Image expansion, see my side patchset
- writing zeroes to raw image with BLOCKDEV_DETECT_ZEROES_OPTIONS_ON set
(actually I have kludged raw-posix.c to have this flag always set
to perform independent testing)
next prev parent reply other threads:[~2014-12-30 11:07 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-30 9:20 [Qemu-devel] [PATCH v3 0/8] eliminate data write in bdrv_write_zeroes on Linux in raw-posix.c Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 1/8] block: prepare bdrv_co_do_write_zeroes to deal with large bl.max_write_zeroes Denis V. Lunev
2015-01-05 7:34 ` Peter Lieven
2015-01-05 11:06 ` Denis V. Lunev
2015-01-05 11:23 ` Peter Lieven
2015-01-05 11:48 ` Denis V. Lunev
2015-01-05 12:26 ` [Qemu-devel] [PATCH v2 1/1] " Denis V. Lunev
2015-01-05 12:32 ` [Qemu-devel] [PATCH v3 " Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 2/8] block: use fallocate(FALLOC_FL_ZERO_RANGE) in handle_aiocb_write_zeroes Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 3/8] block/raw-posix: create do_fallocate helper Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 4/8] block/raw-posix: create translate_err helper to merge errno values Denis V. Lunev
2015-01-05 6:46 ` Fam Zheng
2015-01-05 11:17 ` Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 5/8] block/raw-posix: refactor handle_aiocb_write_zeroes a bit Denis V. Lunev
2015-01-05 6:57 ` Fam Zheng
2015-01-05 11:07 ` Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 6/8] block: use fallocate(FALLOC_FL_PUNCH_HOLE) & fallocate(0) to write zeroes Denis V. Lunev
2015-01-05 7:02 ` Fam Zheng
2015-01-05 11:14 ` Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 7/8] block/raw-posix: call plain fallocate in handle_aiocb_write_zeroes Denis V. Lunev
2014-12-30 9:20 ` [Qemu-devel] [PATCH 8/8] block/raw-posix: set max_write_zeroes to INT_MAX for regular files Denis V. Lunev
2014-12-30 10:55 ` [Qemu-devel] [PATCH v3 0/8] eliminate data write in bdrv_write_zeroes on Linux in raw-posix.c Peter Lieven
2014-12-30 11:07 ` Denis V. Lunev [this message]
2015-01-05 6:55 ` Peter Lieven
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