[Intel-gfx] [PATCH 08/10] drm/i915: Expose per-engine client busyness

[Tvrtko Ursulin]

On 18/03/2020 14:00, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2020-03-18 12:11:37)
>> +static u64
>> +pphwsp_busy_add(struct i915_gem_context *ctx, unsigned int class)
>> +{
>> +       struct i915_gem_engines *engines = rcu_dereference(ctx->engines);
>> +       struct i915_gem_engines_iter it;
>> +       struct intel_context *ce;
>> +       u64 total = 0;
>> +
>> +       for_each_gem_engine(ce, engines, it) {
>> +               if (ce->engine->uabi_class == class)
>> +                       total += ce->runtime.total;
>> +       }
>> +
>> +       return total;
>> +}
>> +
>> +static ssize_t
>> +show_client_busy(struct device *kdev, struct device_attribute *attr, char *buf)
>> +{
>> +       struct i915_engine_busy_attribute *i915_attr =
>> +               container_of(attr, typeof(*i915_attr), attr);
>> +       unsigned int class = i915_attr->engine_class;
>> +       struct i915_drm_client *client = i915_attr->client;
>> +       u64 total = atomic64_read(&client->past_runtime[class]);
>> +       struct list_head *list = &client->ctx_list;
>> +       struct i915_gem_context *ctx;
>> +
>> +       rcu_read_lock();
>> +       list_for_each_entry_rcu(ctx, list, client_link) {
>> +               total += atomic64_read(&ctx->past_runtime[class]);
>> +               total += pphwsp_busy_add(ctx, class);
> 
> Hmm. I would like to have some GEM context agnosticism here. At the
> moment, all I have to offer is
> 
> struct client_runtime {
> 	struct list_head client_link;
> 	atomic64_t past_runtime;
> 	u64 (*cur_runtime)(struct client_runtime *);
> };

What exactly do you mean here? Who keeps a list and of what and what 
does the vfunc do?

Regards,

Tvrtko