svn commit: r191766 - in head/sys: amd64/include amd64/isa
i386/bios i386/include i386/isa i386/xen isa pc98/cbus
jhb at freebsd.org
Mon May 4 19:22:17 UTC 2009
On Sunday 03 May 2009 1:47:21 pm Alexander Motin wrote:
> Author: mav
> Date: Sun May 3 17:47:21 2009
> New Revision: 191766
> URL: http://svn.freebsd.org/changeset/base/191766
> Rename statclock_disable variable to atrtcclock_disable that it actually
> and hide it inside of atrtc driver. Add new tunable hint.atrtc.0.clock
> controlling it. Setting it to 0 disables using RTC clock as stat-/
> profclock sources.
> Teach i386 and amd64 SMP platforms to emulate stat-/profclocks using i8254
> hardclock, when LAPIC and RTC clocks are disabled.
> This allows to reduce global interrupt rate of idle system down to about
> 100 interrupts per core, permitting C3 and deeper C-states provide maximum
> CPU power efficiency.
Note that IRQ0 is not going to work for many systems with the local APIC since
I removed the mixed-mode handling from the x86 interrupt code.
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