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<div class="moz-cite-prefix">On 24/05/18 11:39, Tvrtko Ursulin
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:3822b480-0a4c-c9e8-c28e-38af4435731b@linux.intel.com">
<blockquote type="cite" style="color: #000000;">
<blockquote type="cite" style="color: #000000;">
<blockquote type="cite" style="color: #000000;">---
a/drivers/gpu/drm/i915/i915_gem_context.c
<br>
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
<br>
@@ -981,7 +981,8 @@ int
i915_gem_context_setparam_ioctl(struct drm_device *dev, void
*data,
<br>
break;
<br>
}
<br>
- if (!capable(CAP_SYS_ADMIN)) {
<br>
+ if (!dev_priv->contexts.allow_sseu
&&
<br>
+ !capable(CAP_SYS_ADMIN)) {
<br>
</blockquote>
<br>
So the thing I mentioned in the previous patch. My thinking
was not to fail it if sysfs toggle is disabled, but just don't
do dynamic switching. That way the software stack works in all
cases but user has the option of tuning his system.
<br>
<br>
I mean it can still be done but in userspace. Set param fails,
userspace goes for a fall back.
<br>
<br>
Only difference is I guess whether it is useful to allow
switching at runtime. I am imagining running some 3d and
media, and then toggling the knob to see what happens to power
and performance on the fly. But maybe that is not so
interesting.
<br>
<br>
Along the same lines I was thinking CAP_SYS_ADMIN limitation
could be dropped.
<br>
<br>
Both points are for a wider discussion I guess.
<br>
</blockquote>
<br>
Okay, let's get Dmitry input on this.
<br>
</blockquote>
<br>
To expand, my thinking is to let media stack configure its
contexts for fewer slices, but let the user/sysadmin decide
whether 3d/compute performance is more important, or media.
<br>
<br>
Downside is that with this approach you would have to re-configure
all contexts when sysfs toggle is changed from zero to one.
<br>
</blockquote>
<br>
Right, I've updated this series locally with Tvrkto's latest
comments on v7.<br>
<br>
The issue discussed above is the last remaining detail on which some
kind of decision needs to be taken.<br>
<br>
Ccing Joonas who might have an input.<br>
<br>
Cheers,<br>
<br>
-<br>
Lionel<br>
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