I486_CPU or I586_CPU in kernel config
wblock at wonkity.com
Wed Jun 1 20:46:23 UTC 2011
On Mon, 30 May 2011, Warren Block wrote:
> On Mon, 30 May 2011, Adam Vande More wrote:
>> Perhaps this is the one you meant?
> That's the one! Thanks!
>> Actually the two threads touch on the same subject, and it seems removal of
>> those options is still desirable on newer CPU's.
> sys/i386/i386/support.s is mentioned, but doesn't seem to have anything
> explicitly specific for 586. There are some i686 entries.
> A test for cpu_class==CPUCLASS_586 in /sys/i386/isa/npx.c is mentioned in the
> thread, but that check isn't in the current code.
A little empirical testing:
Times for buildworld after a fresh reboot, /usr/obj/usr deleted,
GENERIC included, running ccache:
default (486/586 included) 9:05.84
nocpu I486, nocpu I586_CPU 9.27.88
nocpu I486_CPU 8.53.86
So maybe a 6% increase by removing 486 but leaving 586... These were
not rigorous benchmarks, it might just be measurement noise.
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