I had misinterpreted the original results... it is interesting that the runtime SE/FS selection outperforms compile time in some cases. It's not clear why that would be the case, unless it's some really subtle thing like the code got moved around which happened to eliminate some icache misses, or something like that.
This all looks good, with the one exception being that an SE compile now takes 31% more user time. It's true that that's negligible wall clock time on a large-scale MP, but not everyone always has access to that. I would still really like us to figure out a way to make compilation more configurable so we can leave out the components that no one needs in SE mode (though ideally that's just one application of a more general mechanism rather than a lingering hard-coded "SE vs FS" difference). Steve On Fri, Jan 27, 2012 at 1:37 AM, Gabriel Michael Black < [email protected]> wrote: > I was, although I'd have to check again what number I used. I set it to > something with the SCONSOPTS (or similar) environment variable on each > computer I use and then don't worry about it any more. You can see that the > "real" time is substantially less than the other times added together, > about 1/6th as much. Since I probably set -j to something more than 6 on > that machine, I'd guess that's around where it saturates. > > Gabe > > > Quoting Korey Sewell <[email protected]>: > > Gabe, >> do you think there will be any more of a difference when you build scons >> with the "-j" flags? (e.g scons -j2 or scons -j4) >> >> >> On Sat, Jan 21, 2012 at 5:38 AM, Gabe Black <[email protected]> >> wrote: >> >> Here are some build time numbers. >>> >>> time scons build/X86/gem5.opt >>> real 4m35.081s >>> user 23m48.901s >>> sys 1m34.119s >>> >>> >>> time scons build/X86_SE/gem5.opt >>> real 4m10.493s >>> user 18m9.749s >>> sys 1m6.644s >>> >>> >>> time scons build/X86_FS/gem5.opt >>> real 4m33.993s >>> user 22m58.946s >>> sys 1m31.277s >>> >>> Gabe >>> ______________________________**_________________ >>> gem5-dev mailing list >>> [email protected] >>> http://m5sim.org/mailman/**listinfo/gem5-dev<http://m5sim.org/mailman/listinfo/gem5-dev> >>> >>> >> >> >> -- >> - Korey >> ______________________________**_________________ >> gem5-dev mailing list >> [email protected] >> http://m5sim.org/mailman/**listinfo/gem5-dev<http://m5sim.org/mailman/listinfo/gem5-dev> >> >> > > ______________________________**_________________ > gem5-dev mailing list > [email protected] > http://m5sim.org/mailman/**listinfo/gem5-dev<http://m5sim.org/mailman/listinfo/gem5-dev> > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
