I ran binutils only with -smp 1 and I get a like 180% runtime. I suspect it's some sort of threading management issue in KVM
Go n-éirí leat, Stuart On Mon, Sep 23, 2013 at 4:30 PM, Bruce Dubbs <bruce.du...@gmail.com> wrote: > Pierre Labastie wrote: > > Le 23/09/2013 18:10, Bruce Dubbs a écrit : > > > >> On the pdf of the above, it measured KVM I/O at about 60% of the host. > >> See pages 56-58. That seems to be consistent with my results. > >> > >> > > It is really amazing, because for the SBU benchmark, I consistently get > not more than > > a 10 % increase of the timings with qemu. I tried also Arch Ubuntu on > the VM, > > (everything -j1, with or without 'cache=writeback', on a qcow2 format. > > > > On this host (core i5), I get 158 (+-2) s on the host and 170 (+-5) s on > the WM. > > Both with -j1 of course. > > > > Here is the qemu command I use: > > > > /usr/bin/qemu-system-x86_64 \ > > -monitor stdio \ > > -smp 4 -cpu Nehalem \ > > -soundhw ac97 \ > > -k fr \ > > -enable-kvm \ > > -m 3915 \ > > -drive file=/mnt/virtualfs/aqemu/blfs.qcow2,cache=writeback \ > > -cdrom /mnt/virtualfs/aqemu/grub-img.iso \ > > -boot order=c,menu=on \ > > -net nic,vlan=0,model=e1000 -net > user,vlan=0,hostfwd=tcp::2222-10.0.2.9:22 \ > > -name "lfs" $* > > Of the options above the only thing I can see that might affect things > are the line -smp 4 -cpu Nehalem. My system is: > > Intel(R) Core(TM)2 Duo CPU E8400 @3.00GHz > > so I can't specify -cpu Nehalem > > What do you get if you specify '-cpu host'? > > I can try specifying -smp 2 and still use make -j1 to see if that makes > a difference. > > I will wait a bit because the system is doing a full LFS build (all > tests) right now. It's chugging away at the Chapter 6 gcc tests right > now and the automake tests always take a while. > > As a side note, the boot time for my system is very fast: about 2 > seconds until starting the boot scripts and another 2 seconds to > complete them. > > -- Bruce > -- > http://linuxfromscratch.org/mailman/listinfo/lfs-dev > FAQ: http://www.linuxfromscratch.org/faq/ > Unsubscribe: See the above information page >
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