Messages in this thread |  | | Date | Fri, 12 Dec 2003 03:00:53 -0500 | From | Jean-Marc Valin <> | Subject | Re: Increasing HZ (patch for HZ > 1000) |
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Just one more thing about the patch I sent. I think it addresses something unclean in the bogomips computation. For example, in arch/i386/kernel/cpu/proc.c, you have:
seq_printf(m, "\nbogomips\t: %lu.%02lu\n\n", c->loops_per_jiffy/(500000/HZ), (c->loops_per_jiffy/(5000/HZ)) % 100);
It's clear that for any case where 5000/HZ is not an integer, the bogomips decimals will be wrong and if 500000/HZ isn't an integer, the bogomips integer part will be wrong.
For example on a 2 GHz processor with a 4000 bogomips value and HZ=1200, the code above will produce 3996.66 instead of 4000. Of course, as soon as HZ goes above 5000, you have a divide by zero right at compile time.
Jean-Marc
-- Jean-Marc Valin, M.Sc.A., ing. jr. LABORIUS (http://www.gel.usherb.ca/laborius) Université de Sherbrooke, Québec, Canada [unhandled content-type:application/pgp-signature] |  |