[bitbake-devel] New progress meters

[Gary Thomas]

On 2016-07-19 11:43, Barros Pena, Belen wrote:
>
>
> On 19/07/2016 10:16, "bitbake-devel-bounces at lists.openembedded.org on
> behalf of Paul Eggleton" <bitbake-devel-bounces at lists.openembedded.org on
> behalf of paul.eggleton at linux.intel.com> wrote:
>
>> Hi Gary,
>>
>> On Tue, 19 Jul 2016 08:33:54 Gary Thomas wrote:
>>> I quite like the new progress meters, but they seem to not be very
>>> accurate.  I was just rebuilding webkitgtk and got this:
>>>
>>> 0: webkitgtk-2.12.3-r0 do_compile (pid 30494)  96%
>>> |#######################################  | ETA:  0:02:58
>>>
>>> Sadly, it sat there, waffling between 02:58 and 03:44 for about
>>> 10 minutes...
>>>
>>> * How is this [estimate] calculated?
>>> * Should I be concerned when it's not accurate (or even moving)?
>>
>> There are a few different types of progress handling for different types
>> of
>> tasks. To be specific in this example, for recipes that inherit cmake
>> during
>> do_compile we report the progress that the cmake-produced makefile prints
>> out.
>> The ETA, which is implemented in the python-progressbar code we are using
>> is
>> kind of a rolling average calculated based on recent progress, so it's
>> possible it's inaccurate in this instance if there are places where it
>> stalls.
>> Python-progressbar has an alternative ETA mode which we could try, but to
>> be
>> honest when the progress value sent to it isn't evenly apportioned with
>> respect to time and we don't have any weighting information, there's not
>> a lot
>> anyone can do to estimate time remaining accurately. If it's truly
>> bothersome
>> we could just turn off the ETA display I suppose.
>
> Big caveat: this is just my opinion. Displaying information we are not
> sure is accurate is probably not a good idea: it disconcerts people,
> creates false expectations and ultimately undermines trust on the system.
>
> If you are not sure the ETA is reliable, I would remove it.

ETA is always that - ESTIMATED.  That said, I'd agree that it should be "close"
or not used at all. Who amongst us has waited for that last 2 minutes downloading
some update...?

>
> Just my 2c.
>
> Cheers
>
> Belén
>
>>
>>> n.b. I wasn't sure the best place for this question, the bitbake
>>> list, generic Yocto or OE-core.  Feel free to redirect as needed.
>>
>> Technically this is an OE question although I know that isn't obvious -
>> there
>> are parts of this that are implemented in BitBake and parts in OE, so
>> asking
>> here is fine.

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------