Re: IA64 implementation of timesource for new time of day subsystem

James Courtier-Dutton
2005-05-15T09:12:10Z

Christoph Lameter wrote:
> On Fri, 13 May 2005, john stultz wrote:
>
>
>>I look forward to your comments and feedback.
>
>
> Here is the implementation of the IA64 timesources for the new time of
> day subsystem.
>
> This is quite straighforward. Thanks John. However, the ITC
> interpolator can no longer use MMIO in SMP situations since there is no
> provision for jitter compensation in the new time of day subsystem. I have
> implemented that via a function now which will slow down clock access
> for non SGI IA64 hardware significantly since it will not be able to use
> the fastcall anymore.
>
> I am working on the fastcall but I would need a couple of changes
> to the core code to make the following symbols non-static since they
> will need to be accessed from the fast syscall handler:
>
> timesource
> system_time
> wall_time_offset
> offset_base
>

Will this mean that Linux will have a monotonic time source?
For media players we need a timesource that does not change under any
circumstances. e.g. User changes the clock time, the monotonic time
source should not change. The monotonic time source should just start at
0 at power on, and continually increase accurately over time. I.e. A
very accurate "uptime" measurement.

James