Re: [PATCH 4/4] tracing: Add __print_ns_to_secs() and __print_ns_without_secs() helpers

Peter Zijlstra
2016-02-23T12:49:25Z

On Mon, Feb 22, 2016 at 04:26:53PM -0500, Steven Rostedt wrote:
> From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
>
> To have nanosecond output displayed in a more human readable format, its
> nicer to convert it to a seconds format (XXX.YYYYYYYYY). The problem is that
> to do so, the numbers must be divided by NSEC_PER_SEC, and moded too. But as
> these numbers are 64 bit, this can not be done simply with '/' and '%'
> operators, but must use do_div() instead.

Would not div_[us]64_rem() make more sense? It would typically result in
just the one division, instead of two.