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<body><span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [SKL] Up to 20% performance regression in GpuTest Triangle, due to 2x higher CPU power usage"
href="https://bugs.freedesktop.org/show_bug.cgi?id=107410">bug 107410</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>FIXED
</td>
</tr>
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<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [SKL] Up to 20% performance regression in GpuTest Triangle, due to 2x higher CPU power usage"
href="https://bugs.freedesktop.org/show_bug.cgi?id=107410#c12">Comment # 12</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [SKL] Up to 20% performance regression in GpuTest Triangle, due to 2x higher CPU power usage"
href="https://bugs.freedesktop.org/show_bug.cgi?id=107410">bug 107410</a>
from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
<pre>commit 01e61a42a5d345a4c0205889498f0c9a0fb9ee8c
Author: Srinivas Pandruvada <<a href="mailto:srinivas.pandruvada@linux.intel.com">srinivas.pandruvada@linux.intel.com</a>>
Date: Mon Jul 30 15:00:29 2018 -0700
cpufreq: intel_pstate: Limit the scope of HWP dynamic boost platforms
Dynamic boosting of HWP performance on IO wake showed significant
improvement to IO workloads. This series was intended for Skylake Xeon
platforms only and feature was enabled by default based on CPU model
number.
But some Xeon platforms reused the Skylake desktop CPU model number. This
caused some undesirable side effects to some graphics workloads. Since
they are heavily IO bound, the increase in CPU performance decreased the
power available for GPU to do its computing and hence decrease in graphics
benchmark performance.
For example on a Skylake desktop, GpuTest benchmark showed average FPS
reduction from 529 to 506.
This change makes sure that HWP boost feature is only enabled for Skylake
server platforms by using ACPI FADT preferred PM Profile. If some desktop
users wants to get benefit of boost, they can still enable boost from
intel_pstate sysfs attribute "hwp_dynamic_boost".
Fixes: 41ab43c9c89e (cpufreq: intel_pstate: enable boost for Skylake Xeon)
Link: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [SKL] Up to 20% performance regression in GpuTest Triangle, due to 2x higher CPU power usage"
href="show_bug.cgi?id=107410">https://bugs.freedesktop.org/show_bug.cgi?id=107410</a>
Reported-by: Eero Tamminen <<a href="mailto:eero.t.tamminen@intel.com">eero.t.tamminen@intel.com</a>>
Signed-off-by: Srinivas Pandruvada <<a href="mailto:srinivas.pandruvada@linux.intel.com">srinivas.pandruvada@linux.intel.com</a>>
Reviewed-by: Francisco Jerez <<a href="mailto:currojerez@riseup.net">currojerez@riseup.net</a>>
Acked-by: Mel Gorman <<a href="mailto:mgorman@techsingularity.net">mgorman@techsingularity.net</a>>
Signed-off-by: Rafael J. Wysocki <<a href="mailto:rafael.j.wysocki@intel.com">rafael.j.wysocki@intel.com</a>></pre>
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