Mesa Falling Back To Its Multi-File Cache Due To Performance Reasons
Mesa has supported on-disk shader cache for years to help speed-up game load times and overall system efficiencies. They had shifted from a multi-file cache layout to a single file cache for greater space savings. Steam also added support for the single-file cache. But now upstream Mesa is shifting back from the single-file cache default to the multi-file cache over performance issues.
Dmitry Osipenko made the change to re-enable the multi-file cache by default. The multi-file cache causes greater disk usage than the single-file cache, but performance issues have been coming up when the single-file cache is rather full.
The MESA_DISK_CACHE_DATABASE=1 can be used to activate the Mesa-DB single file on-disk shader cache for those preferring it, but the default is back with the multi-file cache layout.
In the merge request now merged to Mesa Git it's summed up as:
So for now, back with the multi-file cache which is still better than no cache at all.
Dmitry Osipenko made the change to re-enable the multi-file cache by default. The multi-file cache causes greater disk usage than the single-file cache, but performance issues have been coming up when the single-file cache is rather full.
The MESA_DISK_CACHE_DATABASE=1 can be used to activate the Mesa-DB single file on-disk shader cache for those preferring it, but the default is back with the multi-file cache layout.
In the merge request now merged to Mesa Git it's summed up as:
"Over past months a performance issue was found with the Mesa-DB cache implementation that results in a too slow cache startup time when cache is full. A better indexing strategy will need to be invented to mitigate the issue. Until then, let's default back to the multi-file cache."
So for now, back with the multi-file cache which is still better than no cache at all.