Re: [PATCH 2/2] tracing/hist: add modulus operator

From: Steven Rostedt
Date: Sat Mar 18 2023 - 15:19:12 EST


On Thu, 2 Mar 2023 17:17:55 +0000
Mark Rutland <mark.rutland@xxxxxxx> wrote:

> @@ -436,6 +438,21 @@ static u64 hist_field_mult(struct hist_field *hist_field,
> return val1 * val2;
> }
>
> +static u64 hist_field_mod(struct hist_field *hist_field,
> + struct tracing_map_elt *elt,
> + struct trace_buffer *buffer,
> + struct ring_buffer_event *rbe,
> + void *event)
> +{
> + struct hist_field *operand1 = hist_field->operands[0];
> + struct hist_field *operand2 = hist_field->operands[1];
> +
> + u64 val1 = hist_fn_call(operand1, elt, buffer, rbe, event);
> + u64 val2 = hist_fn_call(operand2, elt, buffer, rbe, event);
> +
> + return val1 % val2;

Is modulus operations on 64 bit integers valid on 32 bit architectures?

Don't we need to do something like:

div64_u64_rem(val1, val2, &rem);
return rem;

?

-- Steve


> +}
> +