Re: 2.6.12-mm1 boot failure on NUMA box.

Lee Revell
2005-06-25T18:08:28Z

On Fri, 2005-06-24 at 23:42 -0700, Martin J. Bligh wrote:
> > (btw., if the TSC is that unreliable on numaq boxes, shouldnt we disable
> > it for userspace apps too? Or are those hangs purely kernel bugs? In
> > which case it might make sense to debug those a bit more - large-scale
> > TSC unsyncedness is something that could slip in on other hardware too.)
>
> Well it reads reliably. it just reliably reads utter random crap (well,
> across CPUs). Not many things read tsc from userspace, and it won't hang
> I guess .... depends what their expecations are. I do like gettimeofday
> not to go backwards though - that tends to bugger things up ;-)

The userspace apps that read the TSC know what they are doing, and have
chosen to use the TSC because they need a cheap, fast timer rather than
a correct one. Please don't break it.

Lee