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    SubjectRe: [PATCH] x86_64: resize NR_IRQS for large machines (re-submit)

    * Alan Mayer <ajm@sgi.com> wrote:

    > On machines with very large numbers of cpus, tables that are
    > dimensioned by NR_IRQS get very large, especially the irq_desc table.
    > They are also very sparsely used. When the cpu count is >
    > MAX_IO_APICS, use MAX_IO_APICS to set NR_IRQS, otherwise use NR_CPUS.

    thanks Alan, applied this in place of the other patch.

    this bit is still ugly:

    > -#define NR_IRQS (NR_VECTORS + (32 *NR_CPUS))
    > +#if NR_CPUS < MAX_IO_APICS
    > +#define NR_IRQS (NR_VECTORS + (32 * NR_CPUS))
    > +#else
    > +#define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS))
    > +#endif
    > #define NR_IRQ_VECTORS NR_IRQS

    but it doesnt really depart from the current status quo of huge
    [NR_IRQS] arrays either. Patches that make NR_IRQS a variable are
    welcome :)

    Ingo


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