On Mon, May 09, 2016 at 11:29:50AM +0530, sourab gupta wrote: > On Sat, 2016-04-23 at 01:19 +0530, Chris Wilson wrote: > > Have you looked at cross-timestamps? > > I was looking at the cross-timestamp patch set > (https://lkml.org/lkml/2016/1/4/541), but I'm not entirely sure the > cross timestamp stuff is solving the same problem. The cross timestamp > stuff is trying to "synchronously capture system/device timestamp(s)". > While here, we have a log of many recorded device timestamps and want to > correlate all of those with system timestamp (_CLOCK_MONOTONOC for now). > As we aren't reading system/device timestamps together for all > timestamps we have, our problem is more about deriving an accurate idea > of timestamp frequency to improve the accuracy when correlating between > the synchronization points. Maybe the cross timestamp stuff will help to > periodically read tightly correlated timestamp pairs synchronously which > can be used as basis for correlating the logged timestamps based on our > derived timestamp frequency. This idea can be evaluated once the cross > timestamp patches land in kernel. My understanding was that the cross-timestamps was for providing the tight coupling between clock sources. It is already available in upstream or -nightly for use. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
