Some shaders, especially RTPSO shaders that have parts of the PSO
inlined, can become absolutely huge. Using a sparse bitset avoids
quadratic complexity in memory consumption for the liveness information.
This reduces peak memory usage in worst-case tests (hammering
compilation of many huge RTPSOs on 32 threads concurrently) by ~60%,
from 43GB to 18GB.
CPU time (seconds) differences for a workload with mostly small shaders:
Difference at 95.0% confidence
-5.27 +/- 1.08963
-0.88811% +/- 0.183626%
(Student's t, pooled s = 0.629735)
Peak resident set usage for the mostly-small workload:
Difference at 95.0% confidence
30809 +/- 13394.3
1.59276% +/- 0.69246%
(Student's t, pooled s = 7741.09)
CPU time for the heavy workload did not show any difference.
Co-authored-by: Alyssa Rosenzweig <alyssa.rosenzweig@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37908>
Natalie Vock
0cb1fca8fa