[lldb-dev] interesting note on build times: configure/make vs. cmake/ninja

[Todd Fiala]

Update: fwiw - I am getting totally inaccurate results when using the gold
debugger + cmake/ninja.  I'll have more to say later, but for sure
something is not building correctly.  I'll have to isolate what is causing
it.

lldb-gdbserver built via cmake/ninja/gold linker was seg faulting, and
neither lldb nor gdb could tell me anything useful about the top few frames
of the core.  Building the same code with configure/(g)make gave me
different results (I got the assert failure printed), and the backtrace
looked quite a bit different.

So - until I figure out which piece of the puzzle isn't working, I don't
think I'd recommend Ubuntu ninja/cmake/gold linker until I figure out which
piece (if only one) that is acting funny.


On Thu, Feb 6, 2014 at 11:40 AM, Todd Fiala <tfiala at google.com> wrote:

> Thanks, Richard.
>
> I spent some time trying that out this morning.  For Ubuntu, I was able to
> do this with 'sudo apt-get install binutils-gold'.  This improved my lldb
> build time with cmake/ninja by between 6 and 7%.  Thanks for the suggestion!
>
> -Todd
>
>
> On Wed, Feb 5, 2014 at 7:48 PM, Richard Mitton <richard at codersnotes.com>wrote:
>
>>  I found with building llvm/lldb, switching your default linker to gold
>> instead of ld helps too.
>>
>>
>> Todd Fiala wrote:
>>
>> Hi all,
>>
>>  Just thought I'd pass along that I've just did a build time comparison
>> between our standard lldb build setup: configure + (g)make (i.e. configure
>> && make -j32), vs. cmake + ninja (i.e. cmake -GNinja && ninja).  On an HP
>> z620 with 32 virtual procs on ssd, it takes me just under 10 minutes to
>> build lldb with configure/make.  The same machine with ninja + cmake takes
>> 4.25 minutes.  *huge* speedup.
>>
>>  We'll be moving in that direction on our dev setups based on that
>> change.  If for some reason we hit any hiccups with that, I'll be sure to
>> tell you about them.
>>  --
>>    Todd Fiala |  Software Engineer |  tfiala at google.com |  650-943-3180
>>
>> ------------------------------
>>
>> _______________________________________________
>> lldb-dev mailing listlldb-dev at cs.uiuc.eduhttp://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>
>>
>
>
> --
> Todd Fiala | Software Engineer |  tfiala at google.com |  650-943-3180
>



-- 
Todd Fiala | Software Engineer | tfiala at google.com | 650-943-3180
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