Re: [PATCH v2 02/12] qapi/block: Add IoAccountingOperation enum

[Markus Armbruster <armbru@redhat.com>]

Hanna Czenczek <hreitz@redhat.com> writes:

> On 20.10.26 07:59, Markus Armbruster wrote:
>> Hanna Czenczek <hreitz@redhat.com> writes:
>>
>>> This enum gives more information than IoOperationType (which is used for
>>> the rerror/werror distinction) to identify operation types for block
>>> accounting.
>>>
>>> Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
>>> ---
>>>   qapi/block.json | 20 ++++++++++++++++++++
>>>   1 file changed, 20 insertions(+)
>>>
>>> diff --git a/qapi/block.json b/qapi/block.json
>>> index 0a88d405a26..8f4a71733c1 100644
>>> --- a/qapi/block.json
>>> +++ b/qapi/block.json
>>> @@ -629,3 +629,23 @@
>>>               'command': 'str' },
>>>     'features': [ 'unstable' ],
>>>     'allow-preconfig': true }
>>> +
>>> +##
>>> +# @IoAccountingOperation:
>>> +#
>>> +# I/O operation types as they are tracked by block accounting.
>>
>> Can we have a link to suitable docs on block accounting?
>
> Which do you have in mind?

Hey, I asked first!

Two ideas to find candidates:

1. How is IoAccountingOperation going to be used?

   I can see events BLOCK_IO_DELAY and BLOCK_IO_DONE.  Documentation
   there calls it "disk operation" in the event description and "I/O
   operation" in the argument description.  Not a peep about
   "accounting".  Might "tracked by block accounting" be about
   implementation?  Or asked differently: why would the user care about
   block accounting here?

2. Assuming "block accounting" is actually relevant for the user: what
   are the QMP interfaces related to it?

> Also, I’m not sure whether these are suitable, because they are the operation types used by block accounting, but for now, accounting cookies (block/accounting.c) use their own non-QAPI enum (enum BlockAcctType).

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