Quoting Chris Wilson (2017-09-06 10:45:57) > Quoting Kenneth Graunke (2017-09-06 01:09:46) > > However, this patch tries to retain the original flushing behavior - it > > adds the amount of batch and state space together, as if they were still > > co-existing in a single buffer. The hope is to flush at the same time > > as before. This is necessary to avoid provoking bugs caused by broken > > batch wrap handling (which we'll fix shortly). It also avoids suddenly > > increasing the size of the batch (due to state not taking up space), > > which could have a significant performance impact. We'll tune it later. > > Note that there is also another potential perf impact from changing > batch sizes, sometimes the smaller batch and lower latency is critical > to keeping the GPU busy. (Not often an issue for us!)
And another situation that can arise when the working set size > GTT, larger batches with more exec_bo cause more swapping. (Smaller batches are less bursty, so fewer stalls.) A good example is gen7 and the UE4 Atlantis demo. -Chris _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
