Buildworld times (was Re: svn commit: r350256 - in stable/12: . contrib/compiler-rt/lib/sanitizer_common contrib/libunwind/src contrib/llvm/lib/DebugInfo/DWARF contrib/llvm/lib/MC contrib/llvm/lib/Object contrib/llvm/lib/Ta...)

[mike tancsa]

On 7/25/2019 12:09 PM, Dimitry Andric wrote:
> Hmmm, is the logic reversed somehow ? The good news is if nothing is
>>> defined, it does the right thing.
>> The idea is that the default is to *not* bootstrap the compiler, if the
>> system compiler is new enough.  E.g. if you build r350256 from a system
>> built before r350256, it will normally automatically bootstrap
>> everything.
>>
>> E.g., your previous builds did not have to bootstrap, and now they do,
>> which is why they take longer.
>>
>> So the only good way to compare is to force MK_SYSTEM_COMPILER=yes and
>> MK_SYSTEM_LINKER=yes, so both buildworlds will do the same thing.
>>
>> I did a few tests on a relatively fast machine, and buildworld with
>> those settings on took approximately the same time at r350255 and
>> r350256.  I'm now repeating those experiments to feed the results to
>> ministat.

Thanks again for verifying and explaining all this.  I was interpreting

MK_SYSTEM_LINKER=yes

as "along with building world, build the compiler and linker from scratch first"

vs

"using the existing installed system linker and compiler to build world"

and as you pointed out, when its a version difference it gets overridden. 

> Repeating buildworld 3 times for r350255 and r350256 (with both


The times on my machines all look normal now too!


    ---Mike