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Subjectstrange `time' results on dual-processor P6 systems
We are attempting to use time(1) to gather some basic performance
statistics on both single and dual-processor P6-200 systems. The
kernel version is 2.0.27. The results appear to be quite wrong.

On a single-processor system, the time values for a test program are:

9.63user 0.18system 0:09.80elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (49major+3912minor)pagefaults 0swaps

9.67user 0.16system 0:09.84elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (49major+3912minor)pagefaults 0swaps

9.62user 0.19system 0:09.81elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (49major+3912minor)pagefaults 0swaps

On the dual-processor system, the time values are:

0.02user 10.47system 0:10.50elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+0minor)pagefaults 0swaps

0.43user 10.06system 0:10.50elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+0minor)pagefaults 0swaps

1.73user 8.76system 0:10.50elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+0minor)pagefaults 0swaps

The elapsed time seems correct on both systems. However, the
proportion of user to system time is more or less reversed and quite
wrong for the dual-processor system.

Any ideas?

This is the test program:

------- start of cut text --------------
#include <stdio.h>

int a[4000000];
main()
{
int i, j;
for( i=0; i<30; ++i )
{
for( j=0; j<4000000; ++j )
++a[j];
}
return( 0 );
}
------- end ----------------------------

--
Daniel Quinlan (at work) Daniel Quinlan (otherwise)
quinlan@transmeta.com http://www.pathname.com/~quinlan/

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