On Fri, Mar 22, 2024 at 02:39:25PM +0800, Xu Yang wrote:
> In current design, the user of perf app needs to input counter ID to count
> events. However, this is not user-friendly since the user needs to lookup
> the map table to find the counter. Instead of letting the user to input
> the counter, let this driver to manage the counters in this patch.
I think we still have to support the old interface so that we don't break
those existing users (even if the driver just ignores whatever counter ID
is provided in a backwards-compatible way).
> This will be implemented by:
> 1. allocate counter 0 for cycle event.
> 2. find unused counter from 1-10 for reference events.
> 3. allocate specific counter for counter-specific events.
>
> In this patch, counter attribute is removed too. To mark counter-specific
> events, counter ID will be encoded into perf_pmu_events_attr.id.
>
> Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>
>
> ---
> Changes in v6:
> - new patch
> Changes in v7:
> - no changes
> Changes in v8:
> - add Rb tag
> ---
> drivers/perf/fsl_imx9_ddr_perf.c | 168 ++++++++++++++++++-------------
> 1 file changed, 99 insertions(+), 69 deletions(-)
>
> diff --git a/drivers/perf/fsl_imx9_ddr_perf.c b/drivers/perf/fsl_imx9_ddr_perf.c
> index 0017f2c9ef91..b728719b494c 100644
> --- a/drivers/perf/fsl_imx9_ddr_perf.c
> +++ b/drivers/perf/fsl_imx9_ddr_perf.c
> @@ -245,14 +249,12 @@ static const struct attribute_group ddr_perf_events_attr_group = {
> .attrs = ddr_perf_events_attrs,
> };
>
> -PMU_FORMAT_ATTR(event, "config:0-7");
> -PMU_FORMAT_ATTR(counter, "config:8-15");
> +PMU_FORMAT_ATTR(event, "config:0-15");
Sadly, this is a user-visible change so I think it will break old tools,
won't it?
Will
