svn commit: r184323 - head/sys/kern

[Dag-Erling Smørgrav]

Maxim Sobolev <sobomax at FreeBSD.org> writes:
> Log:
>   Default HZ value (1,000) on i386/amd64 is not very virtual machine friendly.
>   Due to the nature of the beast it causes lot of unproductive overhead. This
>   is especially bad when running SMP kernel on VMWare with several virtual
>   processors - idle FreeBSD guest with SMP kernel takes 150% host CPU time on my
>   dual-core MacBook Pro when I am enabling two virtual CPUs, making even host
>   not very usable. Detect when we are running in the sandbox and reduce HZ
>   to 10 (can be adjusted via VM_HZ in the kernel config) in such cases. This
>   brings host CPU usage of idle FreeBSD/SMP on two virtual processors down
>   to 10%.

What, too chicken to go whole hog and make the kernel tickless?  :)

DES
-- 
Dag-Erling Smørgrav - des at des.no