Re: [PATCH v5 2/5] block: loop: set QUEUE_FLAG_NOMERGES for request queue of loop

[Ming Lei]

On Wed, Jun 10, 2015 at 3:36 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> On Tue, Jun 09, 2015 at 09:49:23PM +0800, Ming Lei wrote:
>> It doesn't make sense to enable merge because the I/O
>> submitted to backing file is handled page by page.
>
> Looks fine, but does it make any difference?

Looks no, see the following result, please:

- iops tested by fio: loop over image on HDD.
                         patched  vs. non-patched
    randread     158        161
    read             8716        8784
    randwrite     6076        5893
    write             21896        22066

Thanks,
Ming
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