On Mon, 2022-01-10 at 18:56 +0000, Schweikhardt, Markus wrote: > Hi all, > > I would like to monitor the frequency of the iGPU of my TGL platform while running glmark2 in bursts which means glmark2 is 5secrunning and 5sec not > running.I disabled RC6 by echo 0 > /sys/class/drm/card0/gt_rc6_enable for my tests. Furthermore, I tried to lock the iGPU frequency to min, RP0 or > RP1 by setting e.g. Maybe is because you are running a old kerne but recent ones have /sys/class/drm/card0/power/rc6_enable that is read-only. There is no parameter to disable RC6 but you can change the i915 code to not enabled it and run your tests. > echo 1300 > /sys/class/drm/card0/gt_min_freq_mhz > echo 1300 > /sys/class/drm/card0/gt_max_freq_mhz > echo 1300 > /sys/class/drm/card0/gt_boost_freq_mhz. > > For frequency monitoring I am using intel_gpu_top 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. > These are my results if I lock gpu Frequency to 1300MHz > > ### /sys/class/drm/card0/gt_cur_freq_mhz > Every 0.1s: cat > /sys/class/drm/card0/gt_cur_freq_mhz node4- > tglu-rvp: Mon Jan 10 20:22:59 2022 > > 1300 > > ### intel_gpu_top > root@node4-tglu-rvp:~/fGvPOC# intel_gpu_top -l > Freq MHz IRQ RC6 RCS/0 BCS/0 VCS/0 VCS/1 VECS/0 > req act /s % % se wa % se wa % se wa % se wa % se wa > 0 0 15 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 0 0 16 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 0 0 10 100 0.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 188 172 6045 86 13.22 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 1300 1189 44907 0 99.25 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 1300 1201 44702 0 99.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 1300 1182 44873 0 99.23 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 1300 1193 44830 0 99.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 1066 988 36336 19 80.24 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 6 6 10 100 0.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 13 13 15 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 13 13 16 100 0.08 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > 0 0 13 100 0.05 0 0 0.00 0 0 0.00 0 0 0.00 0 0 0.00 0 0 > > Can someone help me to understand why /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? > 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. > > Kernel Info: > Linux node4-tglu-rvp 5.10.41-rt42-intel-ese-standard-lts-rt #1 SMP PREEMPT_RT Thu Sep 23 10:21:35 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux > Intel Yocto BKC MR3 > > Thx, Markus > Intel Deutschland GmbH > Registered Address: Am Campeon 10, 85579 Neubiberg, Germany > Tel: +49 89 99 8853-0, www.intel.de > Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva > Chairperson of the Supervisory Board: Nicole Lau > Registered Office: Munich > Commercial Register: Amtsgericht Muenchen HRB 186928
