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<div>On Wed, 2022-01-12 at 10:40 +0000, Schweikhardt, Markus wrote:</div>
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<pre>Hi Jose,</pre>
<pre><br></pre>
<pre>What is the expected behavior of intel_gpu_top if I lock the frequency to min freq, should I always read req/act = 100/100 even if there is no gfx workload running?</pre>
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<div>That will not prevent RC6 from entering.</div>
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<pre><br></pre>
<pre>-Markus</pre>
<pre><br></pre>
<pre>-----Original Message-----</pre>
<pre>From: Souza, Jose <<a href="mailto:jose.souza@intel.com">jose.souza@intel.com</a>></pre>
<pre>Sent: Monday, January 10, 2022 8:14 PM</pre>
<pre>To: Schweikhardt, Markus <<a href="mailto:markus.schweikhardt@intel.com">markus.schweikhardt@intel.com</a>>; <a href="mailto:intel-gfx@lists.freedesktop.org">intel-gfx@lists.freedesktop.org</a></pre>
<pre>Subject: Re: [Intel-gfx] [TGL-U][iGFX] Monitoring the freq of iGFX with kernel 5.10 on TGL-U i5-1145GRE</pre>
<pre><br></pre>
<pre>On Mon, 2022-01-10 at 18:56 +0000, Schweikhardt, Markus wrote:</pre>
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<pre>Hi all,</pre>
<pre><br></pre>
<pre>I would like to monitor the frequency of the iGPU of my TGL platform</pre>
<pre>while running glmark2 in bursts which means glmark2 is 5secrunning and</pre>
<pre>5sec not running.I disabled RC6 by echo 0 ></pre>
<pre>/sys/class/drm/card0/gt_rc6_enable for my tests. Furthermore, I tried</pre>
<pre>to lock the iGPU frequency to min, RP0 or</pre>
<pre>RP1 by setting e.g.</pre>
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<pre><br></pre>
<pre>Maybe is because you are running a old kerne but recent ones have /sys/class/drm/card0/power/rc6_enable that is read-only.</pre>
<pre>There is no parameter to disable RC6 but you can change the i915 code to not enabled it and run your tests.</pre>
<pre><br></pre>
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<pre>echo 1300 > /sys/class/drm/card0/gt_min_freq_mhz</pre>
<pre>echo 1300 > /sys/class/drm/card0/gt_max_freq_mhz</pre>
<pre>echo 1300 > /sys/class/drm/card0/gt_boost_freq_mhz.</pre>
<pre><br></pre>
<pre>For frequency monitoring I am using intel_gpu_top</pre>
<pre>and/sys/class/drm/card0/gt_cur_freq_mhz. I am a bit confused if I compare the output becauseintel_gpu_top and/sys/class/drm/card0/gt_cur_freq_mhzshow different results.</pre>
<pre>These are my results if I lock gpu Frequency to 1300MHz</pre>
<pre><br></pre>
<pre>### /sys/class/drm/card0/gt_cur_freq_mhz</pre>
<pre>Every 0.1s: cat</pre>
<pre>/sys/class/drm/card0/gt_cur_freq_mhz node4-</pre>
<pre>tglu-rvp: Mon Jan 10 20:22:59 2022</pre>
<pre><br></pre>
<pre>1300</pre>
<pre><br></pre>
<pre>### intel_gpu_top</pre>
<pre>root@node4-tglu-rvp:~/fGvPOC# intel_gpu_top -l</pre>
<pre>Freq MHz IRQ RC6 RCS/0 BCS/0 VCS/0 VCS/1 VECS/0</pre>
<pre>req act /s % % se wa % se wa % se wa % se wa % se wa</pre>
<pre> 0 0 15 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre> 0 0 16 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre> 0 0 10 100 0.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre>188 172 6045 86 13.22 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre>1300 1189 44907 0 99.25 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre>1300 1201 44702 0 99.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre>1300 1182 44873 0 99.23 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre>1300 1193 44830 0 99.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre>1066 988 36336 19 80.24 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre> 6 6 10 100 0.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre> 13 13 15 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre> 13 13 16 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre> 0 0 13 100 0.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0</pre>
<pre><br></pre>
<pre>Can someone help me to understand why</pre>
<pre>/sys/class/drm/card0/gt_cur_freq_mhz always shows 1300MHz and intel_gpu_top (req and act)is dropping to almost 0Hz when glmark2 is not running?</pre>
<pre>My final goal is to figure out if render p-state transitions can impact the timeliness of my real-time workload running on a RT core.</pre>
<pre><br></pre>
<pre>Kernel Info:</pre>
<pre>Linux node4-tglu-rvp 5.10.41-rt42-intel-ese-standard-lts-rt #1 SMP</pre>
<pre>PREEMPT_RT Thu Sep 23 10:21:35 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux</pre>
<pre>Intel Yocto BKC MR3</pre>
<pre><br></pre>
<pre>Thx, Markus</pre>
<pre>Intel Deutschland GmbH</pre>
<pre>Registered Address: Am Campeon 10, 85579 Neubiberg, Germany</pre>
<pre>Tel: +49 89 99 8853-0, <a href="http://www.intel.de">www.intel.de</a></pre>
<pre>Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva</pre>
<pre>Chairperson of the Supervisory Board: Nicole Lau Registered Office:</pre>
<pre>Munich Commercial Register: Amtsgericht Muenchen HRB 186928</pre>
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