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From: Max Reitz <mreitz@redhat.com>
To: Alberto Garcia <berto@igalia.com>,
	Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	"qemu-block@nongnu.org" <qemu-block@nongnu.org>
Cc: Kevin Wolf <kwolf@redhat.com>,
	Anton Nefedov <anton.nefedov@virtuozzo.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [RFC 0/3] block/file-posix: Work around XFS bug
Date: Mon, 4 Nov 2019 17:07:23 +0100	[thread overview]
Message-ID: <d85f6e4f-c1b4-43a4-18a5-918de81b5ac6@redhat.com> (raw)
In-Reply-To: <w51k18fskul.fsf@maestria.local.igalia.com>


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On 04.11.19 16:49, Alberto Garcia wrote:
> On Mon 04 Nov 2019 04:14:56 PM CET, Max Reitz wrote:
> 
>>>> No, what I meant was that the original problem that led to
>>>> c8bb23cbdbe would go away.
>>>
>>> Ah, right. Not quite, according to my numbers:
>>>
>>> |--------------+----------------+-----------------+-------------|
>>> | Cluster size | subclusters=on | subclusters=off | fallocate() |
>>> |--------------+----------------+-----------------+-------------|
>>> |       256 KB |     10182 IOPS |        966 IOPS |  14007 IOPS |
>>> |       512 KB |      7919 IOPS |        563 IOPS |  13442 IOPS |
>>> |      1024 KB |      5050 IOPS |        465 IOPS |  13887 IOPS |
>>> |      2048 KB |      2465 IOPS |        271 IOPS |  13885 IOPS |
>>> |--------------+----------------+-----------------+-------------|
>>>
>>> There's obviously no backing image, and only the last column uses
>>> handle_alloc_space() / fallocate().
>>
>> Thanks for providing some numbers!
>>
>> It was my impression, too, that subclusters wouldn’t solve it.  But it
>> didn’t seem like that big of a difference to me.  Did you run this
>> with aio=native?  (Because that’s where we have the XFS problem)
> 
> Here's with aio=native
> 
> |--------------+----------------+-----------------+-------------|
> | Cluster size | subclusters=on | subclusters=off | fallocate() |
> |--------------+----------------+-----------------+-------------|
> |       256 KB |     19897 IOPS |        891 IOPS |  32194 IOPS |
> |       512 KB |     17881 IOPS |        436 IOPS |  33092 IOPS |
> |      1024 KB |     17050 IOPS |        341 IOPS |  32768 IOPS |
> |      2048 KB |      7854 IOPS |        207 IOPS |  30944 IOPS |
> |--------------+----------------+-----------------+-------------|

OK, thanks again. :-)

So it seems right not to revert the commit and just work around the XFS
bug in file-posix.

Max


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  reply	other threads:[~2019-11-04 16:09 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-25  9:58 [RFC 0/3] block/file-posix: Work around XFS bug Max Reitz
2019-10-25  9:58 ` [RFC 1/3] block: Make wait/mark serialising requests public Max Reitz
2019-10-25  9:58 ` [RFC 2/3] block/file-posix: Detect XFS with CONFIG_FALLOCATE Max Reitz
2019-10-25 10:19   ` Kevin Wolf
2019-10-25 10:22     ` Max Reitz
2019-10-25 10:35       ` Kevin Wolf
2019-10-25 10:41         ` Max Reitz
2019-10-26 17:26   ` Nir Soffer
2019-10-25  9:58 ` [RFC 3/3] block/file-posix: Let post-EOF fallocate serialize Max Reitz
2019-10-26 17:28   ` Nir Soffer
2019-10-25 13:40 ` [RFC 0/3] block/file-posix: Work around XFS bug Vladimir Sementsov-Ogievskiy
2019-10-25 13:56   ` Vladimir Sementsov-Ogievskiy
2019-10-25 14:19     ` Max Reitz
2019-10-25 14:35       ` Kevin Wolf
2019-10-25 14:36       ` Vladimir Sementsov-Ogievskiy
2019-10-27 12:21         ` Stefan Hajnoczi
2019-11-04 14:03       ` Alberto Garcia
2019-11-04 14:25         ` Max Reitz
2019-11-04 15:12           ` Alberto Garcia
2019-11-04 15:14             ` Max Reitz
2019-11-04 15:49               ` Alberto Garcia
2019-11-04 16:07                 ` Max Reitz [this message]
2019-10-25 13:46 ` Peter Maydell
2019-10-25 14:16   ` Max Reitz
2019-10-25 14:17     ` Peter Maydell
2019-10-25 14:21       ` Max Reitz
2019-10-25 14:56         ` Peter Maydell
2019-10-26  0:14 ` no-reply
2019-10-26 17:37 ` Nir Soffer
2019-10-26 17:52   ` Vladimir Sementsov-Ogievskiy
2019-10-28  8:56     ` Max Reitz
2019-10-27 12:35 ` Stefan Hajnoczi
2019-10-28  9:24   ` Max Reitz
2019-10-28  9:30     ` Max Reitz
2019-10-28  9:56       ` Max Reitz
2019-10-28 10:07         ` Vladimir Sementsov-Ogievskiy
2019-10-28 10:10           ` Max Reitz
2019-10-28 11:19             ` Vladimir Sementsov-Ogievskiy
2019-10-28 11:04   ` Kevin Wolf
2019-10-28 11:25     ` Vladimir Sementsov-Ogievskiy
2019-10-29  8:50       ` Max Reitz
2019-10-29 11:48         ` Vladimir Sementsov-Ogievskiy
2019-10-29 11:55           ` Max Reitz
2019-10-29 12:05             ` Vladimir Sementsov-Ogievskiy
2019-10-29 12:11               ` Max Reitz
2019-10-29 12:19                 ` Vladimir Sementsov-Ogievskiy
2019-10-29 12:23                   ` Max Reitz

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