The beginning of the 5.12 merge window was delayed as the result of severe
weather in the US Pacific Northwest. Once Linus Torvalds got going, though, he
wasted little time; as of this writing, just over 8,600 non-merge
changesets have been pulled into the mainline repository for the 5.12
release u2014 over a period of about two days. As one might imagine, that work
contains a long list of significant changes.

Source: LWN.net – [$] 5.12 Merge window, part 1