[Intel-gfx] [RFC 08/12] drm/i915: Expose per-engine client busyness

[Tvrtko Ursulin]

On 10/03/2020 18:32, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2020-03-09 18:31:25)
>> +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);
>> +       }
>> +       rcu_read_unlock();
>> +
>> +       total *= RUNTIME_INFO(i915_attr->i915)->cs_timestamp_period_ns;
> 
> Planning early retirement? In 600 years, they'll have forgotten how to
> email ;)

Shruggety shrug. :) I am guessing you would prefer both internal 
representations (sw and pphwsp runtimes) to be consistently in 
nanoseconds? I thought why multiply at various places when once at the 
readout time is enough.

And I should mention again how I am not sure at the moment how to meld 
the two stats into one more "perfect" output.

Regards,

Tvrtko