<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][SHARDS] igt@kms_flip@flip-vs-expired-vblank - Failed assertion: gettime_us() - start < 500" href="https://bugs.freedesktop.org/show_bug.cgi?id=105363#c9">Comment # 9</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][SHARDS] igt@kms_flip@flip-vs-expired-vblank - Failed assertion: gettime_us() - start < 500" href="https://bugs.freedesktop.org/show_bug.cgi?id=105363">bug 105363</a> from <a class="email" href="mailto:arkadiusz.hiler@intel.com" title="Arek Hiler <arkadiusz.hiler@intel.com>"> Arek Hiler</a> <pre>Few notes: 1. The message could be improved. It seems to suggest that this is interval between vblanks instead of the time it takes doing a wait on expired one 2. Going through recent logs the time is usually ~25us with occasional spikes to ~150us. And there are the outliers which we fail on: (kms_flip:1816) DEBUG: Vblank took 1456us (kms_flip:5124) DEBUG: Vblank took 1088us (kms_flip:1373) DEBUG: Vblank took 501us (kms_flip:2150) DEBUG: Vblank took 842us (kms_flip:5198) DEBUG: Vblank took 3301us Still no idea what may cause this. It seems to be too much of a lag even for very unfavourable scheduling. The only locking that happens on the call path is in drm_vblank_get() which takes on a few spinlocks. I believe it's worth investigating. 3ms of delay for 16ms frames (60fps) is a lot.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>