Re: [PATCH] x86: Intel Cache Allocation Technology support

From: Thomas Gleixner
Date: Fri Nov 21 2014 - 15:43:43 EST


On Fri, 21 Nov 2014, Dave Hansen wrote:
> On 11/19/2014 05:05 PM, Vikas Shivappa wrote:
> > + /*
> > + * Hard code the checks and values for HSW SKUs.
> > + * Unfortunately! have to check against only these brand name strings.
> > + */
> > +
> > + for (i = 0; i < 5; i++)
> > + if (!strcmp(hsw_brandstrs[i], c->x86_model_id)) {
> > + c->x86_cqe_closs = 4;
> > + c->x86_cqe_cbmlength = 20;
> > + return true;
> > + }
>
> Please use ARRAY_SIZE() here. Otherwise, I guarantee the next string
> you add to hsw_brandstrs[] gets silently ignored.
>
> Are there really only 5 CPUs? This:
>
> > http://ark.intel.com/products/family/78583/Intel-Xeon-Processor-E5-v3-Family#@Server
>
> lists 32 skus.

We really should find a proper software probing solution for this
instead of having a gazillion of brand strings plus micro code version
checks around for this.

Why cant the HW folks release a micro code version which fixes the
obviously wreckaged CPUID enumeration of this feature instead of
burdening us with that horror?

Can you please find a proper sized clue bat and whack your HW folks
over the head for this insanity?

Thanks,

tglx
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