RE: [PATCH] clocksource=tsc

["Dan Magenheimer" <dan.magenheimer@oracle.com>]

OK, ignore that.  It looks like you have it all fixed
in 18060.  I tried it and it now boots.  Thanks!

> -----Original Message-----
> From: Dan Magenheimer [mailto:dan.magenheimer@oracle.com]
> Sent: Tuesday, July 15, 2008 7:16 PM
> To: 'dan.magenheimer@oracle.com'; 'Keir Fraser'; 'Xen-Devel (E-mail)'
> Cc: 'Dave Winchell'
> Subject: RE: [PATCH] clocksource=tsc
> 
> 
> > > > Returning to 32-bit read_counter(), and having NULL 
> > > read_counter when
> > > > clocksource=tsc would be another possibility...
> 
> Well I hacked on 18055 for awhile and just couldn't get it
> to boot.  I think local_time_calibration() (and thus
> init_percpu_time()) is necessary for boot, though I'm not really
> sure why.  Possibly the "Weirdness can happen..." comment in
> that routine?
> 
> Anyway, this patch (on top of 18055) DOES work, returns to the
> 32-bit read_counter, and re-enables local_time_calibration().
> I'd suggest putting off more major surgery for another day.
> 
> Thanks,
> Dan
> 
> > -----Original Message-----
> > From: Dan Magenheimer [mailto:dan.magenheimer@oracle.com]
> > Sent: Tuesday, July 15, 2008 10:04 AM
> > To: dan.magenheimer@oracle.com; Keir Fraser; Xen-Devel (E-mail)
> > Cc: Dave Winchell
> > Subject: RE: [PATCH] clocksource=tsc
> > 
> > 
> > Hmmm... 18055 also fails to boot on my machine.
> > 
> > Could we perhaps fall back to my original patch and do
> > cleanup later/separately?  I also want to try implementing
> > an hpet64-based get_s_time() so will be working more
> > in this code later... but want to get clocksource=tsc
> > working now with minimal code impact given the freeze.
> > 
> > > -----Original Message-----
> > > From: Dan Magenheimer [mailto:dan.magenheimer@oracle.com]
> > > Sent: Tuesday, July 15, 2008 9:46 AM
> > > To: 'Keir Fraser'; 'Xen-Devel (E-mail)'
> > > Cc: 'Dave Winchell'
> > > Subject: RE: [PATCH] clocksource=tsc
> > > 
> > > > Actually in this mode of operation we hardly need a platform 
> > > > timer *at all*.
> > > > The idea is that we let the TSCs free-run, because we know 
> > > > they will behave.
> > > > Returning to 32-bit read_counter(), and having NULL 
> > > read_counter when
> > > > clocksource=tsc would be another possibility...
> > > 
> > > That's essentially what the original tscstable.patch did, though
> > > I was perhaps much uglier in the miscellaneous parts.
> > > 
> > > Thanks,
> > > Dan
> > >
> > 
> >