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<div class="moz-cite-prefix">On 13/03/2020 17:26, Tvrtko Ursulin
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:10ecf815-71b1-bdcf-1588-df726698c119@linux.intel.com"><br>
On 13/03/2020 14:34, Lionel Landwerlin wrote:
<br>
<blockquote type="cite" style="color: #000000;">On Gen11
powergating half the execution units is a functional
<br>
requirement when using the VME samplers. Not fullfilling this
<br>
requirement can lead to hangs.
<br>
<br>
This unfortunately plays fairly poorly with the NOA
requirements. NOA
<br>
requires a stable power configuration to maintain its
configuration.
<br>
<br>
As a result using OA (and NOA feeding into it) so far has
required us
<br>
to use a power configuration that can work for all contexts. The
only
<br>
power configuration fullfilling this is powergating half the
execution
<br>
units.
<br>
<br>
This makes performance analysis for 3D workloads somewhat
pointless.
<br>
<br>
Failing to find a solution that would work for everybody, this
change
<br>
introduces a new i915-perf stream open parameter that punts the
<br>
decision off to userspace. If this parameter is omitted, the
existing
<br>
Gen11 behavior remains (half EU array powergating).
<br>
<br>
This change takes the initiative to move all perf related sseu
<br>
configuration into i915_perf.c
<br>
<br>
v2: Make parameter priviliged if different from default
<br>
<br>
v3: Fix context modifying its sseu config while i915-perf is
enabled
<br>
<br>
v4: Always consider global sseu a privileged operation (Tvrtko)
<br>
Override req_sseu point in intel_sseu_make_rpcs() (Tvrtko)
<br>
Remove unrelated changes (Tvrtko)
<br>
<br>
v5: Some typos (Tvrtko)
<br>
Process sseu param in read_properties_unlocked() (Tvrtko)
<br>
</blockquote>
<br>
git add ? <span class="moz-smiley-s1" title=":)"><span>:)</span></span>
<br>
<br>
Regards,
<br>
<br>
Tvrtko
<br>
</blockquote>
<p><br>
</p>
<p>Oh dear...</p>
<p>Sorry for that.</p>
<p><br>
</p>
<p>-Lionel<br>
</p>
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