Re: [PATCH v5 0/5] Initial support for multi-actuator HDDs

On 2021/08/26 12:43, Martin K. Petersen wrote:

Damien,

quoted

I am not super happy with the name either. I used this one as the
least worst of possibilities I thought of.  seek_range/srange ? ->
that is very HDD centric and as we can reuse this for things like
dm-linear on top of SSDs, that does not really work.  I would prefer
something that convey the idea of "parallel command execution", since
this is the main point of the interface. prange ? cdm_range ?
req_range ?

How about independent_access_range? That doesn't imply head positioning
and can also be used to describe a fault domain. And it is less
disk-centric than concurrent_positioning_range.

I like it, but a bit long-ish. Do you think shortening to access_range would be
acceptable ?

we would have:

/sys/block/XYZ/queue/access_ranges/...

and

struct blk_access_range {
	...
	sector_t sector;
	sector_t nr_sectors;
}

struct blk_access_range *arange;

Adding independent does make everything even more obvious, but names become
rather long. Not an issue for the sysfs directory I think, but

struct blk_independent_access_range {
	...
	sector_t sector;
	sector_t nr_sectors;
}

is rather a long struct name. Shortening independent to "ind" could very easily
be confused with "indirection", so that is not an option. And "iaccess" is
obscure...

I concur that those names are a bit unwieldy but at least they are
somewhat descriptive.

I consulted the thesaurus and didn't really like the other options
(discrete, disjoint, separate, etc.). I think 'independent' is more
accurate for this and better than 'concurrent' and 'parallel'.

-- 
Damien Le Moal
Western Digital Research