svn commit: r212541 - in head/sys: amd64/amd64 amd64/include dev/acpica i386/i386 i386/include kern mips/include mips/mips pc98/pc98 powerpc/aim powerpc/booke powerpc/include powerpc/powerpc sparc6...

[Alexander Best]

On Mon Sep 13 10, Alexander Motin wrote:
> [snip]
>   
>   There is set of tunables, also available as writable sysctls, allowing to
>   control wanted event timer subsystem behavior:
>     kern.eventtimer.timer - allows to choose event timer hardware to use.
>   On x86 there is up to 4 different kinds of timers. Depending on whether
>   chosen timer is per-CPU, behavior of other options slightly differs.
>     kern.eventtimer.periodic - allows to choose periodic and one-shot
>   operation mode. In periodic mode, current timer hardware taken as the only
>   source of time for time events. This mode is quite alike to previous kernel
>   behavior. One-shot mode instead uses currently selected time counter
>   hardware to schedule all needed events one by one and program timer to
>   generate interrupt exactly in specified time. Default value depends of
>   chosen timer capabilities, but one-shot mode is preferred, until other is
>   forced by user or hardware.
>     kern.eventtimer.singlemul - in periodic mode specifies how much times
>   higher timer frequency should be, to not strictly alias hardclock() and
>   statclock() events. Default values are 2 and 4, but could be reduced to 1
>   if extra interrupts are unwanted.
>     kern.eventtimer.idletick - makes each CPU to receive every timer interrupt
>   independently of whether they busy or not. By default this options is
>   disabled. If chosen timer is per-CPU and runs in periodic mode, this option
>   has no effect - all interrupts are generating.
>   
>   [snip]

great! :)

would it be possible to document these tunables in a new manual or add them to
an existing one? sorry if i missed this and they are already documented
somewhere.

-- 
a13x