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

From: Vikas Shivappa
Date: Fri Nov 21 2014 - 16:27:33 EST

On Fri, 21 Nov 2014, Thomas Gleixner wrote:

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:

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?
Ok , we were in the process of checking this as its not usual to make 5 expensive brand strings. Will update status in next version.




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