On 03/31/2011 02:35 AM, Ingo Molnar wrote: > > * Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote: > >>> Btw., we used to auto-detect broken HLT systems IIRC - but that got lost >>> already. We should at least honor the boot parameter. >> >> I don't believe we ever auto detected them or found a way to do so. That >> was why the HLT message was printed before hlt was executed. > > Yeah - the CPU hang was unrecoverably deep so no auto-detection was possible. > > That's seriously ancient stuff - still, keeping the boot option around (<10 > lines of code) does not hurt anyone. > What it was was bad power supplies or low-capacitance, high-inductance power distribution that happened to work with MS-DOS which always burned the CPU at 100% and therefore left the power draw relatively consistent current. A proper OS putting the CPU in HLT produced a lot more high frequency noise on the power busses, with disastrous results without proper bypass. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
