Re: [PATCH] scsi: sd: Do not override max_sectors_kb sysfs setting

Martin Wilck
2017-09-29T12:26:38Z

On Wed, 2017-09-27 at 21:38 -0400, Martin K. Petersen wrote:
> A user may lower the max_sectors_kb setting in sysfs to accommodate
> certain workloads. Previously we would always set the max I/O size to
> either the block layer default or the optional preferred I/O size
> reported by the device.
>
> Keep the current heuristics for the initial setting of
> max_sectors_kb.
> For subsequent invocations, only update the current queue limit if it
> exceeds the capabilities of the hardware.
>
> Reported-by: Don Brace <don.brace@microsemi.com>
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This looks good to me. I agree that it's superior to the original
suggestion, because it sets the soft limit to the hard limit when the
device is scanned for the first time.

Regards
Martin

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