[U-Boot] [PATCH 2/2] WIP: Test version of buildman - U-Boot builder

[Simon Glass]

Hi Wolfgang,

On Wed, Oct 31, 2012 at 4:37 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon,
>
> In message <CAPnjgZ1qV=Odn93NMWEeAOzOOeBHyWwXB21s+n+cXXh0nan=eg at mail.gmail.com> you wrote:
>>
>> Yes...it's mostly for building a list of commits (e.g. an entire
>> branch) and automatically tracking and showing what boards break
>> between commits. It is optimised for this - e.g. it can build 22
>> commits for 1000 boards (22,000 builds) in about an hour on a fast
>> machine, which is a few times faster than I have managed with MAKEALL.
>
> Do you have an explanation why this is so?  There must be some
> fundamental difference, and I would really like to understand that.

I think it is partly that it checks out each commit and builds it
incrementally (without throwing away existing files). So checking out
the next commit may not affect the board being built at all, in which
case the build is very fast.

Also rather than running with 'make -j40' or whatever, it uses 'make
-j1' but with 40 threads. This increases CPU utilisation quite
substantially (almost 50%) - I think this was discussed some time ago,
and was something that Mike's buildall script did. But I found that it
had conflicts and was hard to use. For example, it seems to be unhappy
when different board were configured to different architectures
(something to do with include path confusion which I hope is now fixed
- partly the subject of my efb2172 commit). Also, it prints all the
output in a bit of a mess, so it's hard to see what board it relates
to, and you have to go back to the log files to see.

>
>> It is a completely different tool, yes, but I have found myself using
>> it instead of what I previously used: MAKEALL plus Mike's 'buildall'
>> wrapper. The main thing I like about it is that it quickly shows me
>> which builds are broken by which commits, and what the errors were.
>>
>> I have posted it since it's not a lot of use having it privately - it
>> might be useful to others.
>
> Pleasae don;t misunderstand me.  I really appreciate your posting.
> And if this tool is really that fast, I want to have it, and the
> sooner the better.  But then, we should dump MAKEALL, especially if
> it's so slow.
>
> In the end, there should be just one such tool...

Well I hope we can have a period of trying it out :-) Let's see what
people think, and there is still work to do. It has become my tool of
choice, but only in the last few months.

Regards,
Simon

>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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