Re: [PATCH 09/13] drm/msm: Add per-context perfcntr state

[Dmitry Baryshkov]

On Mon, Apr 20, 2026 at 03:25:31PM -0700, Rob Clark wrote:
> The upcoming PERFCNTR_CONFIG ioctl will allow for both global counter
> collection, and per-context counter reservation for local (ie. within
> a single GEM_SUBMIT ioctl) counter collection.
> 
> Any number of contexts can reserve the same counters, but we will need
> to ensure that counters reserved for local counter collection do not
> conflict with counters used for global counter collection.
> 
> So add tracking for per-context local counter reservations.
> 
> Signed-off-by: Rob Clark <robin.clark@xxxxxxxxxxxxxxxx>

> 
> +struct msm_perfcntr_context_state {
> +	/**
> +	 * @reserved_counters:
> +	 *
> +	 * The number of reserved counters indexed by perfcntr group.
> +	 */
> +	unsigned reserved_counters[];
> +};

Fails here (Debian, trixie, gcc 14.2) with:

In file included from drivers/gpu/drm/msm/generated/a6xx_perfcntrs.json.c:7:
./drivers/gpu/drm/msm/msm_perfcntr.h:130:18: error: flexible array member in a struct with no named members
  130 |         unsigned reserved_counters[];
      |                  ^~~~~~~~~~~~~~~~~

> +
>  extern const struct msm_perfcntr_group a6xx_perfcntr_groups[];
>  extern const unsigned a6xx_num_perfcntr_groups;
>  

-- 
With best wishes
Dmitry