[Intel-gfx] [RFC 5/8] drm/i915: Add support for forwarding ring id in sample metadata through perf

[Chris Wilson]

On Wed, Aug 05, 2015 at 11:25:41AM +0530, sourab.gupta at intel.com wrote:
> @@ -542,18 +548,27 @@ static void forward_one_gen_pmu_sample(struct drm_i915_private *dev_priv,
>  	struct perf_sample_data data;
>  	struct perf_event *event = dev_priv->gen_pmu.exclusive_event;
>  	int snapshot_size;
> -	u8 *snapshot;
> +	u8 *snapshot, *current_ptr;
>  	struct drm_i915_ts_node_ctx_id *ctx_info;
> +	struct drm_i915_ts_node_ring_id *ring_info;
>  	struct perf_raw_record raw;
>  
> -	BUILD_BUG_ON(TS_DATA_SIZE != 8);
> -	BUILD_BUG_ON(CTX_INFO_SIZE != 8);
> +	BUILD_BUG_ON((TS_DATA_SIZE != 8) || (CTX_INFO_SIZE != 8) ||
> +			(RING_INFO_SIZE != 8));
>  
>  	snapshot = dev_priv->gen_pmu.buffer.addr + node->offset;
>  	snapshot_size = TS_DATA_SIZE + CTX_INFO_SIZE;
>  
>  	ctx_info = (struct drm_i915_ts_node_ctx_id *)(snapshot + TS_DATA_SIZE);
>  	ctx_info->ctx_id = node->ctx_id;
> +	current_ptr = snapshot + snapshot_size;
> +
> +	if (dev_priv->gen_pmu.sample_info_flags & I915_GEN_PMU_SAMPLE_RING) {
> +		ring_info = (struct drm_i915_ts_node_ring_id *)current_ptr;
> +		ring_info->ring = node->ring;

Stylewise I would be move familar with current_ptr = ring_info + 1, and
make current_ptr void*. snapshot_size is then redundant.

> +		snapshot_size += RING_INFO_SIZE;
> +		current_ptr = snapshot + snapshot_size;
> +	}

-- 
Chris Wilson, Intel Open Source Technology Centre