<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [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#c8">Comment # 8</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [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 <a class="email" href="mailto:eero.t.tamminen@intel.com" title="Eero Tamminen <eero.t.tamminen@intel.com>"> Eero Tamminen</a> <pre>(In reply to Srinivas Pandruvada from <a href="show_bug.cgi?id=107410#c6">comment #6</a>) > First check if you have > /sys/devices/system/cpu/intel_pstate/hwp_dynamic_boost == 1 > Unfortunately some Xeon E3 reused DESKTOP CPU ID. It's "1" on the regressing SKL machines, and "0" on the "U" one that didn't regress. > If yes, as Chris suggested, try > #echo 0 > /sys/devices/system/cpu/intel_pstate/hwp_dynamic_boost > > If this fixes At least the largest GpuTest Triangle regression disappears. > try the attached patch. I'm running the full set of benchmarks with this, so it takes a while. I'll report results tomorrow. > After this patch should be > /sys/devices/system/cpu/intel_pstate/hwp_dynamic_boost == 0 if your platform > is not a E3. With the patch it's "0". (In reply to Srinivas Pandruvada from <a href="show_bug.cgi?id=107410#c7">comment #7</a>) > Also do test on clear Linux, which always runs in performance mode? Why? I assume this is not just to test performance governor [1]... 1. We're tracking upstream Git versions, not older distro versions of SW, so we build our own git versions of (drm-tip) kernel and rest of the 3D stack, and use those also on Clear Linux (currently we use Clear only on BXT). 2. You need to define what you mean by "Clear Linux". It updates frequently and at least I haven't yet found a way to determine what its packages have actually been built from/with. Its package management doesn't seem to provide the basic information of: - which exact sources - what patches - compile options Are used to build a package. [1] We switched to powersave governor a while because it gives slightly better performance in (3D) benchmarks than Clear Linux default "performance" governor, and didn't regress in any of our (3D) benchmarks. Besides, with Francisco's P-state improvements applied on top of it, (3D / IGP) perf improves very noticeably (only) with powersave.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>