PF & SMP
Matthew Dillon
dillon at apollo.backplane.com
Sun Sep 24 15:26:30 PDT 2006
:I'm not shure I understood correctly the meaning of those number, and
:their impact on actual smp speedup (or lack thereof)..
:
:How does that correlate to speedup on a parallel build ?
:for instance.. build -j8:
:- in UP mode > 1450s
:- in SMP mode > 825s (1450/2 + 100)?
:
:sorry, I don't have a smp system to test out...
:
:best regards
:--
:Miguel Sousa Filipe
No, it's a bit more complex then that. make -j builds do not run
processes in parallel all the time, there are a number of places
during the build where everything collapses into a single target
or requirement. There are also a number of places where the
machine is I/O bound and SMP becomes irrelevant, and at least one
place (during the compilation of GCC) where the machine can become
memory bound.
-Matt
Matthew Dillon
<dillon at xxxxxxxxxxxxx>
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