Re: [PATCH 02/14] hw/core/clock: trace clock values in Hz instead of ns

[Philippe Mathieu-Daudé]

On 9/25/20 12:17 PM, Luc Michel wrote:
> The nanosecond unit greatly limits the dynamic range we can display in
> clock value traces, for values in the order of 1GHz and more. The
> internal representation can go way beyond this value and it is quite
> common for today's clocks to be within those ranges.
> 
> For example, a frequency between 500MHz+ and 1GHz will be displayed as
> 1ns. Beyond 1GHz, it will show up as 0ns.
> 
> Replace nanosecond periods traces with frequencies in the Hz unit
> to have more dynamic range in the trace output.

I have a similar patch adding the freq but keeping the periods in
case, as it might be a matter of taste (for me too the frequency
is more meaningful).

> 
> Signed-off-by: Luc Michel <luc@lmichel.fr>
> ---
>  hw/core/clock.c      | 6 +++---
>  hw/core/trace-events | 4 ++--
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/core/clock.c b/hw/core/clock.c
> index 7066282f7b..81184734e0 100644
> --- a/hw/core/clock.c
> +++ b/hw/core/clock.c
> @@ -37,12 +37,12 @@ void clock_clear_callback(Clock *clk)
>  bool clock_set(Clock *clk, uint64_t period)
>  {
>      if (clk->period == period) {
>          return false;
>      }
> -    trace_clock_set(CLOCK_PATH(clk), CLOCK_PERIOD_TO_NS(clk->period),
> -                    CLOCK_PERIOD_TO_NS(period));
> +    trace_clock_set(CLOCK_PATH(clk), CLOCK_PERIOD_TO_HZ(clk->period),
> +                    CLOCK_PERIOD_TO_HZ(period));
>      clk->period = period;
>  
>      return true;
>  }
>  
> @@ -52,11 +52,11 @@ static void clock_propagate_period(Clock *clk, bool 
> call_callbacks)
>  
>      QLIST_FOREACH(child, &clk->children, sibling) {
>          if (child->period != clk->period) {
>              child->period = clk->period;
>              trace_clock_update(CLOCK_PATH(child), CLOCK_PATH(clk),
> -                               CLOCK_PERIOD_TO_NS(clk->period),
> +                               CLOCK_PERIOD_TO_HZ(clk->period),
>                                 call_callbacks);
>              if (call_callbacks && child->callback) {
>                  child->callback(child->callback_opaque);
>              }
>              clock_propagate_period(child, call_callbacks);
> diff --git a/hw/core/trace-events b/hw/core/trace-events
> index 1ac60ede6b..6f96d8bfd0 100644
> --- a/hw/core/trace-events
> +++ b/hw/core/trace-events
> @@ -29,8 +29,8 @@ resettable_phase_exit_end(void *obj, const char *objtype, 
> unsigned count) "obj=%
>  resettable_transitional_function(void *obj, const char *objtype) "obj=%p(%s)"
>  
>  # clock.c
>  clock_set_source(const char *clk, const char *src) "'%s', src='%s'"
>  clock_disconnect(const char *clk) "'%s'"
> -clock_set(const char *clk, uint64_t old, uint64_t new) "'%s', 
> ns=%"PRIu64"->%"PRIu64
> +clock_set(const char *clk, uint64_t old, uint64_t new) "'%s', 
> %"PRIu64"hz->%"PRIu64"hz"

Unit is spell 'Hz'.

>  clock_propagate(const char *clk) "'%s'"
> -clock_update(const char *clk, const char *src, uint64_t val, int cb) "'%s', 
> src='%s', ns=%"PRIu64", cb=%d"
> +clock_update(const char *clk, const char *src, uint64_t hz, int cb) "'%s', 
> src='%s', val=%"PRIu64"hz cb=%d"

Ditto.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>