<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - 3% perf drop in GfxBench Manhattan 3.0, 3.1 and CarChase test-cases" href="https://bugs.freedesktop.org/show_bug.cgi?id=111090#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - 3% perf drop in GfxBench Manhattan 3.0, 3.1 and CarChase test-cases" href="https://bugs.freedesktop.org/show_bug.cgi?id=111090">bug 111090</a> from <a class="email" href="mailto:eero.t.tamminen@intel.com" title="Eero Tamminen <eero.t.tamminen@intel.com>"> Eero Tamminen</a> <pre>Lakshmi, although you marked this as BXT, there was some impact visible also on KBL GT3e. I don't think issue is BXT specific, it's visibility just depends on relative CPU/GPU/bandwidth balance, not absolute performance, and/or how TDP limited the device is. (In reply to Chris Wilson from <a href="show_bug.cgi?id=111090#c1">comment #1</a>) > drm/i915/execlists: Minimalistic timeslicing ... > is at least one intentional change in the scheduling that may interfere with > throughput tests (like gfxbench) in the presence of third parties (X) also > trying to render. All the impacted tests are complex/heavy ones, and they run in fullscreen under Unity which handles fullscreen properly (unlike Gnome [1]) and disables compositing. I.e. there's only single process rendering during these benchmarks. (In reply to Chris Wilson from <a href="show_bug.cgi?id=111090#c2">comment #2</a>) > I would say the biggest potential impact there is: > drm/i915: Move GEM object domain management from struct_mutex to local > drm/i915: Drop the deferred active reference > > Removing struct_mutex should have been an improvement (reducing lock > contention, and at worse not making it any worse), so the extra burden of > active reference tracking? In case it helps, these tests have hundreds of drawcalls per frame and don't have a any single bottleneck, bottleneck can change many times during frame. Unlike the other benchmarks I'm running, the most impacted Manhattan tests use UBOs and transform feedback. What about drm-tip non-i915 code changes from upstream rebases? Test machines use P-state power management mode and GPU benchmarks on TDP-limited devices could be impacted also by non-i915 kernel changes. [1] <a href="https://gitlab.gnome.org/GNOME/mutter/issues/60">https://gitlab.gnome.org/GNOME/mutter/issues/60</a></pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>