On Gen11 powergating half the execution units is a functional requirement when using the VME samplers. Not fullfilling this requirement can lead to hangs. This unfortunately plays fairly poorly with the NOA requirements. NOA requires a stable power configuration to maintain its configuration. As a result using OA (and NOA feeding into it) so far has required us to use a power configuration that can work for all contexts. The only power configuration fullfilling this is powergating half the execution units. This makes performance analysis for 3D workloads somewhat pointless. Failing to find a solution that would work for everybody, this change introduces a new i915-perf stream open parameter that punts the decision off to userspace. If this parameter is omitted, the existing Gen11 behavior remains (half EU array powergating). This change takes the initiative to move all perf related sseu configuration into i915_perf.c v2: Make parameter priviliged if different from default v3: Fix context modifying its sseu config while i915-perf is enabled v4: Always consider global sseu a privileged operation (Tvrtko) Override req_sseu point in intel_sseu_make_rpcs() (Tvrtko) Remove unrelated changes (Tvrtko) v5: Some typos (Tvrtko) Process sseu param in read_properties_unlocked() (Tvrtko) v6: Actually commit the bits from v5... Fixup some checkpath warnings v7: Only compare engine uabi field (Chris)
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| @@ -1969,6 +1969,17 @@ enum drm_i915_perf_property_id { · 1968 unmodified lines | ||
| 1969 | 1969 | */ |
| 1970 | 1970 | DRM_I915_PERF_PROP_HOLD_PREEMPTION, |
| 1971 | 1971 | |
| 1972 | + /** | |
| 1973 | + * Specifying this pins all contexts to the specified SSEU power | |
| 1974 | + * configuration for the duration of the recording. | |
| 1975 | + * | |
| 1976 | + * This parameter's value is a pointer to a struct | |
| 1977 | + * drm_i915_gem_context_param_sseu. | |
| 1978 | + * | |
| 1979 | + * This property is available in perf revision 4. | |
| 1980 | + */ | |
| 1981 | + DRM_I915_PERF_PROP_GLOBAL_SSEU, | |
| 1982 | + | |
| 1972 | 1983 | DRM_I915_PERF_PROP_MAX /* non-ABI */ |
| 1973 | 1984 | }; |
| 1974 | 1985 | |