Performance issue

Pete French
Mon, 09 May 2005 09:11:00 -0000

> Whereas, the typical result for the new rig looked more like
>
>       105.36 real        71.10 user        33.41 sys
...
>      10548  involuntary context switches

Now I just ran this test myself. This machine is a 2.4 gig P4 with
hyperthreading enabled. Much as I am an AMD fan, I would expect a 1gig
Athlon to be significantly slower than a 2.4 gig Pentium 4.

but:

       93.45 real        56.55 user        36.85 sys
      1857  involuntary context switches

Uhhh... so it takes almost the same time to do the calculation, but spends
actually *more* of it in system space. Does far less context switches though,
but I am assuming thats due to HTT.

Numbers look very odd to me. So I then ran it on another P4 system we have
round here which is still running 4.11. This is a 2.66 gig P4, not a 2.4
so it should be a bit faster, but:

       33.77 real        33.49 user         0.07 sys
       711  involuntary context switches

Over two and a half times faster ?! Thats not right at all!

All the new systems I have tried are 5.4-RC4, so should be the
latest and greatest. When my colleague finishes on his machine I
can try a GENERIC 5.4-RC4 kernel on another P4 and see what that
gives.

-pcf.