Re: HT apparently not detected properly on 2.4.23

From: Marcelo Tosatti
Date: Fri Dec 05 2003 - 12:46:40 EST

On Wed, 3 Dec 2003, William Lee Irwin III wrote:

> William Lee Irwin III wrote:
> >>You probably have sparse physical APIC ID's.
> On Wed, Dec 03, 2003 at 06:41:36PM -0500, Ethan Weinstein wrote:
> > Ok, setting CONFIG_NR_CPUS=8 does indeed solve the HT issue, looks like
> > it was the numbering scheme:
> It's easy to fix this; just terminate the loop when the count of cpus
> kicked hits NR_CPUS or the bit would overflow the map instead of the bit
> hitting NR_CPUS. Compare smpboot.c in 2.4 vs. 2.6. No need for the extra
> On Wed, Dec 03, 2003 at 06:41:36PM -0500, Ethan Weinstein wrote:
> > But we're still only interrupting on CPU0 with this kernel.
> That's P-IV retardation. Not really fixable, but irqbalance daemons
> etc. can help mitigate the severity of the erratum. I'm not sure if
> 2.4 has the interfaces for the userspace solutions to work or the
> kernel solutions either.

I think I will just remove CONFIG_NR_CPUS instead... it seems to bring
more trouble than advantages.

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