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Re: GCC 4.1: Buildable on GHz machines only?
On Wed, 27 Apr 2005 16:52:25 -0400, Paul Koning <pkoning@equallogic.com> said:
> However, I can always tell when a GCC build has hit the libjava build
> -- that's when the *whole system* suddenly slows to a crawl. Maybe
> it comes from doing some processing on 5000 foo.o files all at
> once... :-(
It's also too bad the final steps of the libjava build aren't more
parallelizable, though I can't say I have any productive suggestions
to add there. I just tried a C/C++ bootstrap and a C/C++/Java
bootstrap on a four-processor machine; the latter took 2.6 times as
long as the former, and for most of the non-compilation part of the
libjava build, three of the processors were sitting around being
bored. (Not that I really know exactly what was causing the delays;
maybe the disk and memory were being stressed enough by the single
processor that was active.)
This also showed up a little in the C build: while make found other
stuff to do while gen-attrtab was going on, shortly after it started
compiling insn-attrtab.c, make ran out of other files to compile.
Not that I'm really complaining: you can get quite a lot of mileage
out of multiple CPUs as it is, more than enough (in my opinion) to
justify purchasing some nice build servers by software shops that do a
lot of GCC work. (I won't post the actual bootstrap times out of fear
of being lynched.) This might show up more as people start moving
towards dual-core and/or multiple CPU systems even on the low end.
David Carlton
david.carlton@sun.com