Re: RFD: Should we remove the HLT check? (was Re: [PATCH 1/8] x86: avoid check hlt if no timer interrupts)

H. Peter Anvin
2010-05-07T22:28:35Z

On 05/07/2010 03:24 PM, Alan Cox wrote:
>> I'd be cool skipping it for family 5 or newer. I'm just wondering if we
>> should kill it completely -- IIRC it was only a handful of 386/486
>> systems which had problems, usually due to marginal power supplies which
>> couldn't handle the noise of a variable load (DOS not having any power
>> management would run at a reliable 100% load) -- that's not exactly the
>> type of systems which would have survived to modern day.
>
> Also SMM and hardware bugs on some platforms - Cyrix MediaGX 5510 for
> example where a hlt at the wrong moment during ATA transfers hung the box
> until power cycle. But all old old stuff.

I think family < 5 seems a reasonable cutoff.

Note that the ATA transfer bug you describe above would not be caught by
the existing check.

-hpa