[Xen-devel] Re: [RFC PATCH 25/35] Add Xen time abstractions

[Chris Wright <chrisw@xxxxxxxxxxxx>]

* Ingo Oeser (ioe-lkml@xxxxxxxxxx) wrote:
> On Tuesday, 9. May 2006 23:50, Andi Kleen wrote:
> > On Tuesday 09 May 2006 09:00, Chris Wright wrote:
> > > Add support for Xen time abstractions. To avoid expensive traps into
> > > the hypervisor, the passage of time is extrapolated from the local TSC
> > > and a set of timestamps and scaling factors exported to the guest via
> > > shared memory. Xen also provides a periodic interrupt facility which
> > > is used to drive updates of xtime and jiffies, and perform the usual
> > > process accounting and profiling.
> > 
> > There is far too much code duplication in there. I think you need to
> > refactor the main time.c a bit first and strip that down.
> > 
> > Also you can drop all the __x86_64__ support for now.
> 
> Isn't time and timer handling a moving target anyway?
> The refactoring will be done by the timer people in a completly different
> manner anyway.
> 
> Are you sure, you want to disturb these efforts by requiring another
> refactoring here?

Yes.  Otherwise we end up with either duplicated code if the moving
target winds up not moving, or outdated code if it does.  I agree with
Andi.  It's on the todo list to refactor, but I wanted to get the
patches out even though it's a work in progress.

thanks,
-chris

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