FYI: what it takes for RAM+swap to build devel/llvm40 with 4 processors or cores and WITH__DEBUG= (powerpc64 example)

[Mark Millard]

On 2017-Mar-27, at 2:41 AM, Dimitry Andric <dim at FreeBSD.org> wrote:

> On 26 Mar 2017, at 23:36, Mark Millard <markmi at dsl-only.net> wrote:
>> 
>> I upgraded from llvm40 r4 to final. An interesting result was
>> its creation of a backup package for llvm40-4.0.0.r4:
>> 
>> about 13 cpu-core-hours running pkg create
>> 
>> (Remember: I've been building with WITH_DEBUG= ) Its
>> single-threaded status stands out via elapsed time
>> approximately matching.
>> 
>> I'll note that it was somewhat under 6 elapsed hours for
>> staging to have been populated (-j4 with 4 cores present
>> helps for this part).
>> 
>> (Of course these elapsed-time figures are rather system
>> dependent, although the ratio might be more stable.)
>> 
>> 
>> 
>> Also interesting was:
>> 
>> Installed packages to be REMOVED:
>> 	llvm40-4.0.0.r4
>> 
>> Number of packages to be removed: 1
>> 
>> The operation will free 49 GiB.
> 
> Yes, this is big.  But there is no real need to build the llvm ports
> with debug information, unless you want to hack on llvm itself.  And
> in that case, you are better served by a Subversion checkout or Git
> clone from upstream instead.
> 
> -Dimitry

FYI:

Historically unless something extreme like this ends up
involved I build everything using WITH_DEBUG=  or explicit
-g's in order to have better information on any failure.

This is extreme enough that next time I synchronize
/usr/ports and it has a devel/llvm40 update I'll
likely rebuild devel/llvm40 without using WITH_DEBUG= .
I'm more concerned with the time it takes than with
the file system space involved.

===
Mark Millard
markmi at dsl-only.net