Re: [HACKERS] Compile timing

> Lamar Owen wrote:
> 
> >
> > Bruce Momjian wrote:
> > >
> > > Someone mentioned that it took them quite a while to compile the
> > > PostgreSQL code.  My wallclock time is 3:52 for a compile with -O1 using
> > > gcc 2.7.2.1.  This is on a dual-PII 350MHz running BSD/OS 4.01.
> 
> Hmmm,
> 
>     Is  there  something  wrong with your system, Bruce?  My 64MB
>     333MHz singe-PII (same gcc version under Linux 2.2.10) does a
>     -O1 clean-compile in 3:28.
> 
>     Maybe  the SMP overhead is eating up the missing cycles.  You
>     would like a parallelized make to outperform me again - no?

I knew someone would find this an interesting topic.

I should also mention I have 256MB of RAM, and Baracuda SCSI-Ultra
drives with tagged queuing enabled.

OK, I turned off my custom flags, and got for -O1:
real    3m8.080suser    2m21.752ssys     0m35.291s

I usually do:
CUSTOM_COPT=-g -Wall -O1 -Wmissing-prototypes -Wmissing-declarations

My bet is the symbol output takes some time to produce.  I noticed the
link of the postgres binary was faster without -g.

With parallelization, using gmake -j2, I got:
real    3m8.980suser    2m23.442ssys     0m36.142s

Not sure why -j2 is not faster than normal -j, unless gmake knows to use
-j2 on a 2-cpu system by default.  Looking at the xps output, I don't
see multiple compiles being performed by gmake.

Gmake -j fails because compiles happen before supporting files are
created.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
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