Messages in this thread | | | Date | Thu, 14 Aug 2008 09:33:26 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] irq: sparse irqs, fix #2 |
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On Thu, 14 Aug 2008 15:36:52 +0200 Ingo Molnar <mingo@elte.hu> wrote:
> +static inline cpumask_t vector_allocation_domain(int cpu) > +{ > + /* Careful. Some cpus do not strictly honor the set of cpus > + * specified in the interrupt destination when using lowest > + * priority interrupt delivery mode. > + * > + * In particular there was a hyperthreading cpu observed to > + * deliver interrupts to the wrong hyperthread when only one > + * hyperthread was specified in the interrupt desitination. > + */ > + cpumask_t domain = { { [0] = APIC_ALL_CPUS, } }; > + return domain; > +}
I haven't looked at callers of this, but...
Does it need to be allocated on the stack? Local cpumask_t's are a size problem. Can we build this in .rodata at compile time instead?
Is this the caller?
+ for_each_cpu_mask(cpu, mask) { + cpumask_t domain, new_mask; + int new_cpu; + int vector; + + domain = vector_allocation_domain(cpu); + cpus_and(new_mask, domain, cpu_online_map);
If so we could perhaps do
static noinline const cpumask_t *vector_allocation_domain(int cpu) { /* Careful. Some cpus do not strictly honor the set of cpus * specified in the interrupt destination when using lowest * priority interrupt delivery mode. * * In particular there was a hyperthreading cpu observed to * deliver interrupts to the wrong hyperthread when only one * hyperthread was specified in the interrupt desitination. */ static const cpumask_t domain = { { [0] = APIC_ALL_CPUS, } }; return &domain; }
...
+ for_each_cpu_mask(cpu, mask) { + cpumask_t domain, new_mask; + int new_cpu; + int vector; + + __cpus_and(new_mask, vector_allocation_domain(cpu), + &cpu_online_map);
otoh, perhaps this new function is one implementation of genapic.vector_allocation_domain(), in which case the inlining was unneeded and misleading.
I give up. Have a little think about the stack bloat, please.
btw, whoever wrote that function is in need of a tab key.
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