Re: [PATCH v3 04/10] hbitmap: drop meta bitmaps as they are unused

[Vladimir Sementsov-Ogievskiy]

20.01.2020 20:05, Max Reitz wrote:
> On 20.01.20 17:20, Vladimir Sementsov-Ogievskiy wrote:
>> 20.01.2020 14:13, Max Reitz wrote:
>>> On 19.12.19 11:03, Vladimir Sementsov-Ogievskiy wrote:
>>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
>>>> ---
>>>>    include/qemu/hbitmap.h |  21 --------
>>>>    tests/test-hbitmap.c   | 115 -----------------------------------------
>>>>    util/hbitmap.c         |  16 ------
>>>>    3 files changed, 152 deletions(-)
>>>
>>> Er, hrm, well.
>>>
>>> Reviewed-by: Max Reitz <address@hidden>
>>>
>>> git log me the only commits that touched anything to the regard of
>>> '*create_meta*' were the ones that introduced it and your commit that
>>> dropped it.
>>>
>>> Soo, er, well, okay.  Why did we introduce these again?  (I suppose I
>>> should know since they have my S-o-b on them.  But I actually don’t.)
>>>
>>> Max
>>>
>>
>> I'm a bit not follow what you mean. I can just note, that dirty-bitmap.c
>> part of meta bitmaps was recently removed, and hbitmap.c part I forgot to
>> remove...
> 
> Yes, but who used that dirty-bitmap.c interface?  As far as I can tell,
> nobody.

Yes, as far as I know, nobody and never.

> 
>> Meta bitmaps were intended to control live migration of bitmaps and to
>> implement something like partial sync of bitmaps (write to qcow2 only
>> changed part of bitmap), but migration implemented in other way
>> (postcopy) and the second thing was not implemented.
> 
> OK.  I was wondering why they were implemented without ever having been
> used (as far as I can tell).
> 

It was too optimistic preparatory series.

(I can never finally understand, series - who a they or what is it?
  Plural or singular? They were too optimistic series? Sounds weird..
  And if one series is series, than what about several serieses?
  OK, let's say, it was too optimistic preparatory patch set :)


-- 
Best regards,
Vladimir