Re: [RFC PATCH v2 4/8] smp: Trace IPIs sent via arch_send_call_function_ipi_mask()

From: Peter Zijlstra
Date: Thu Nov 17 2022 - 04:09:01 EST


On Wed, Nov 02, 2022 at 06:33:32PM +0000, Valentin Schneider wrote:
> This simply wraps around the arch function and prepends it with a
> tracepoint, similar to send_call_function_single_ipi().
>
> Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
> ---
> kernel/smp.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/smp.c b/kernel/smp.c
> index e2ca1e2f31274..c4d561cf50d45 100644
> --- a/kernel/smp.c
> +++ b/kernel/smp.c
> @@ -160,6 +160,13 @@ void __init call_function_init(void)
> smpcfd_prepare_cpu(smp_processor_id());
> }
>
> +static inline void

Given the use of _RET_IP_, I would strongly recommend you use
__always_inline.

> +send_call_function_ipi_mask(const struct cpumask *mask)
> +{
> + trace_ipi_send_cpumask(mask, _RET_IP_, func);

What's func?

> + arch_send_call_function_ipi_mask(mask);
> +}