Re: [PATCH 2/11] x86: convert to generic helpers for IPI function calls

[Jeremy Fitzhardinge <jeremy@goop.org>]

Jens Axboe wrote:
> --- a/arch/x86/kernel/smp.c
> +++ b/arch/x86/kernel/smp.c
>   
[...]
> +void arch_send_call_function_single_ipi(int cpu)
>  {
>   
[...]
> +void arch_send_call_function_ipi(cpumask_t mask)
>  {
>   
[...]
> --- a/arch/x86/xen/smp.c
> +++ b/arch/x86/xen/smp.c
> +void arch_send_call_function_ipi(cpumask_t mask)
> +{
>   
[...]
> +void arch_send_call_function_single_ipi(int cpu)
> +{
> +	xen_send_IPI_mask(cpumask_of_cpu(cpu), XEN_CALL_FUNCTION_SINGLE_VECTOR);
>  

Xen vs native is a runtime choice, so you can't just statically define 
arch_send_call_function(_single)_ipi for each.  You need to define the 
arch_* functions once, make them call via smp_ops, and call into the 
respective native and Xen versions of the ipi functions.

Aside from that it looks good, with a very appealing code size reduction.

    J