Performance hitch when typing in the search box while versions tab is open about ckan

[HebaruSan]

I think we have over-parallelization here. RelationshipResolver.ModList is parallel (for speeding up very large changesets), and Versions.checkInstallable calls it in parallel (via ModuleInstaller.CanInstall; that's what feeds the ToList call highlighted above). This nesting can do wacky things to threads; I hit this a couple of times while parallelizing other stuff. This probably also explains why the Versions tab doesn't start filling in right away.

That link recommends only parallelizing the outer loop.

[HebaruSan]

... confirmed (more or less). Commenting this line makes the inner loop non-parallel, which makes the response to color the list instantaneous and fixes the hang-up issue in the OP:

CKAN/Core/Relationships/RelationshipResolver.cs

Line 525 in 3b16d38

.AsParallel()

... but I think we'll want to be able to make that conditional somehow in case there are other places that would still benefit from it being parallel...