From: Ruediger Meier <sweet_f_a@gmx.de>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Karel Zak <kzak@redhat.com>,
util-linux@vger.kernel.org,
SCSI development list <linux-scsi@vger.kernel.org>,
Douglas Gilbert <dgilbert@interlog.com>
Subject: Re: scsi_debug, iosize optimal < minimum
Date: Wed, 3 Feb 2016 22:55:44 +0100 [thread overview]
Message-ID: <201602032255.44508.sweet_f_a@gmx.de> (raw)
In-Reply-To: <yq1fuxcr5lk.fsf@sermon.lab.mkp.net>
On Monday 01 February 2016, Martin K. Petersen wrote:
> >>>>> "Ruediger" == Ruediger Meier <sweet_f_a@gmx.de> writes:
>
> Ruediger> I've noticed a possible problem with scsi_debug devices
> where Ruediger> optimal_io_size < minimum_io_size.
>
> Ruediger> The problem seems reproducable with kernel 4.4.0 and also
> with Ruediger> stable version 4.1.15. For stable tree the last known
> working Ruediger> version is 4.1.13.
>
> http://git.kernel.org/cgit/linux/kernel/git/mkp/scsi.git/commit/?h=4.
>5/scsi-fixes&id=d0eb20a863ba7dc1d3f4b841639671f134560be2
Ah thanks!
But I'm still wondering a bit. Using kernel 4.5-rc2 (where 9c1d9c20 and
d0eb20a8 is included) I get
$ getconf PAGESIZE
4096
$ modprobe scsi_debug
$ cat /sys/block/$devname/queue/{minimum_io_size,optimal_io_size}
512
524288
In past (kernel<=4.1) optimal_io_size io size was 32768. Is this really
correct now?
cu,
Rudi
next prev parent reply other threads:[~2016-02-03 21:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-29 10:31 test sfdisk, optimal_iosize Ruediger Meier
2016-01-29 11:31 ` Karel Zak
2016-01-29 11:52 ` Karel Zak
2016-01-29 13:02 ` Ruediger Meier
2016-01-29 16:18 ` scsi_debug, iosize optimal < minimum (was: test sfdisk, optimal_iosize) Ruediger Meier
2016-02-01 12:13 ` scsi_debug, iosize optimal < minimum Martin K. Petersen
2016-02-03 21:55 ` Ruediger Meier [this message]
2016-02-03 22:02 ` Martin K. Petersen
2016-02-04 10:47 ` Ruediger Meier
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