Hi all,
On 9/22/06, Joerg Sonnenberger <[EMAIL PROTECTED]> wrote:
On Fri, Sep 22, 2006 at 09:38:31AM -0700, Matthew Dillon wrote: > As part of my parallel buildworld test I record the contention > count delta for each -j 8 build. I typically get numbers in the > 800-900 million range. x 100 ns pertick == about 100 seconds of wasted > of cpu (for both cpus together) for a buildworld that takes 1450 seconds, > and dividing by the two cpus, that probably represents a real-world > loss in build time of between 4% and 7% over what it could hav achieved. > That is a very rough estimate, I haven't actually measured what a 'tick' > is... it could be less then 100ns but I don't think it is more. Hm. On my build machine: around 3e6/s during a parallel build... Joerg
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 -- Miguel Sousa Filipe
