Re: [PATCH v20 01/12] block: Introduce queue limits and sysfs for copy-offload support

From: Christoph Hellwig
Date: Wed Jun 05 2024 - 04:23:05 EST


On Tue, Jun 04, 2024 at 09:05:03AM +0200, Hannes Reinecke wrote:
> On 6/4/24 06:31, Christoph Hellwig wrote:
>> On Mon, Jun 03, 2024 at 06:43:56AM +0000, Nitesh Shetty wrote:
>>>> Also most block limits are in kb. Not that I really know why we are
>>>> doing that, but is there a good reason to deviate from that scheme?
>>>>
>>> We followed discard as a reference, but we can move to kb, if that helps
>>> with overall readability.
>>
>> I'm not really sure what is better. Does anyone remember why we did
>> the _kb version? Either way some amount of consistency would be nice.
>>
> If memory serves correctly we introduced the _kb versions as a convenience
> to the user; exposing values in 512 bytes increments tended
> to be confusing, especially when it comes to LBA values (is the size in
> units of hardware sector size? 512 increments? kilobytes?)

Maybe. In the meantime I did a bit more of research, and only
max_sectors and max_hw_sectors are reported in kb. chunk_sectors is
reported in 512 byte sectors, and everything else is reported in bytes.

So sticking to bytes is probably right, and I was wrong about "most block
limits above". Sorry.