<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [IVB][REGRESSION] i915: Intermittent short system stutter / lag affecting graphics output; bisected to commit f8d03ea" href="https://bugs.freedesktop.org/show_bug.cgi?id=97139#c1">Comment # 1</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [IVB][REGRESSION] i915: Intermittent short system stutter / lag affecting graphics output; bisected to commit f8d03ea" href="https://bugs.freedesktop.org/show_bug.cgi?id=97139">bug 97139</a> from <a class="email" href="mailto:yorickpeterse@gmail.com" title="Yorick Peterse <yorickpeterse@gmail.com>"> Yorick Peterse</a> <pre>I recently got myself a 4K display (Dell 2715Q) and ran into this problem as well. I never noticed it on my laptop's display (X1 Carbon 3rd generation using a WQHD display). Measuring frame rates using glxgears would occassionally show a drop from 59.9 frames to around 56 frames per second. Based on the notes left by the reporter I hacked together the patch named "drm_msleep_470.patch". This patch basically changes the sleep time from 10 milliseconds to just 1 millisecond. After compiling the drm module with this patch and rebooting it appears the problem has been "solved", though this probably won't work for other setups. I tested this by again running glxgears for a while and noticed no drops in frame rate. The patch is based on Linux 4.7.0, it _may_ work with different versions but I have not tested this. The patch was generated using "git diff". Yorick</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>