On May 6, 10:05 am, Dan Drake <[EMAIL PROTECTED]> wrote: Hi Dan
> I have access to a dual processor machine, so I thought I'd try out the > new pbuild stuff in 3.0.1. Unfortunately, exporting SAGE_BUILD_THREADS=3 > and SAGE_PBUILD=yes resulted in a *slower* build: > > real 205m21.375s > user 184m45.427s > sys 24m50.515s > > was at the bottom after running `make'. When I cleared those variables > and ran `make' in a clean tree, I got > > real 144m59.654s > user 111m43.727s > sys 18m36.220s > > When the supposed pbuild was running, I ran top in another window and it > seemed like it was never actually running more than one process at a > time; top consistently reported about 50% idle and a load average near > 1. IIRC you also saw quiet odd things happening with ptest. Since ptest and pbuild use the same/similar infrastructure you either could be exposing a bug in ptest/pbuild or your platform. There are some debug options in pbuild that can be turned on, but Gary should say more about that. But even if pbuild is only running one thread at a time it should still compile roughly as fast as setup.py since it is more or less doing the exact same amount of work. So I am puzzled. > Below are some specs for the machine. Any thoughts on why it isn't > actually doing a parallel build? > > It's a Fedora 7 box; uname -a gives > > Linux vinh505.math.umn.edu 2.6.23.15-80.fc7 #1 SMP Sun Feb 10 17:29:10 > EST 2008 i686 athlon i386 GNU/Linux > > and /proc/cpuinfo is > > processor : 0 > vendor_id : AuthenticAMD > cpu family : 6 > model : 8 > model name : AMD Athlon(tm) MP 2600+ > stepping : 1 > cpu MHz : 2133.460 > cache size : 256 KB > fdiv_bug : no > hlt_bug : no > f00f_bug : no > coma_bug : no > fpu : yes > fpu_exception : yes > cpuid level : 1 > wp : yes > flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov > pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow ts > bogomips : 4270.04 > clflush size : 32 > > processor : 1 > vendor_id : AuthenticAMD > cpu family : 6 > model : 8 > model name : AMD Athlon(tm) Processor > stepping : 1 > cpu MHz : 2133.460 > cache size : 256 KB > fdiv_bug : no > hlt_bug : no > f00f_bug : no > coma_bug : no > fpu : yes > fpu_exception : yes > cpuid level : 1 > wp : yes > flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov > pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow ts > bogomips : 4266.20 > clflush size : 32 What seems odd to me is that cpuinfo reports different CPUs: > model name : AMD Athlon(tm) MP 2600+ > model name : AMD Athlon(tm) Processor Since that is generally not a good idea therein may lay your trouble. I am sure that mixing and matching CPUs [i.e. MP with non-MP] is not supported by AMD and it seems a sheer coincidence that your setup even boots. Should they both be "AMD Athlon(tm) MP 2600+" CPUs then something else hardware wise is probably broken. So in conclusion I expect your hardware/software setup to be at fault here until proven innocent :) In general: If you start two intense jobs in parallel do they run consuming as much CPU time as when they are run sequentially? Cheers, Michael > -- > --- Dan Drake <[EMAIL PROTECTED]> > ----- KAIST Department of Mathematical Sciences > ------- http://math.kaist.ac.kr/~drake > > signature.asc > 1KDownload --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
