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Date:   Thu, 20 Jul 2023 09:06:12 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Nitesh Shetty <nj.shetty@samsung.com>
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Subject: Re: [PATCH v13 1/9] block: Introduce queue limits for copy-offload
 support
Message-ID: <20230720070612.GA4722@lst.de>
References: <20230627183629.26571-1-nj.shetty@samsung.com> <CGME20230627184000epcas5p1c7cb01eb1c70bc5a19f76ce21f2ec3f8@epcas5p1.samsung.com> <20230627183629.26571-2-nj.shetty@samsung.com>
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Just a little heads up:  I think we need to properly solve the
hw vs user limit as the various ad-hoc mechanisms tend to be
broken and don't scale.  I plan to start looking into that the
next days.

On Wed, Jun 28, 2023 at 12:06:15AM +0530, Nitesh Shetty wrote:
> Add device limits as sysfs entries,
>         - copy_offload (RW)
>         - copy_max_bytes (RW)
>         - copy_max_bytes_hw (RO)
> 
> Above limits help to split the copy payload in block layer.
> copy_offload: used for setting copy offload(1) or emulation(0).
> copy_max_bytes: maximum total length of copy in single payload.
> copy_max_bytes_hw: Reflects the device supported maximum limit.

Why do we need the separate copy_offload boolean vs just looking
at the max_bytes value?