The 6.4 kernel was released
on June 25 after a nine-week development cycle. By that point, 14,835
non-merge changesets had been pulled into the mainline kernel, a slight
increase from 6.3 (14,424 changesets) but still lower than many other
development cycles. As usual, LWN has taken a look at those changesets,
who contributed them, and what the most active developers were up to.

Source: LWN.net – [$] Development statistics for 6.4