A commiter le is írja, hogy ennek egy részét a 6.12-be tervezték, de kiderült, hogy nem várhat:
Lots of little fixes and two big items, which were orgiinally slated for the 6.12 merge window but turned out to be pretty important.
The big items are: - rhashtable conversion for VFS inodes cache Thas was slated for the 6.12 merge window, but a deadlock was uncovered in __wait_for_freeing_inode(); bcachefs inverts the usual locking between the VFS inode cache and on disk (btree) locking, with some advantages and some extra trickyness. The result was that we were waiting (via __wait_for_freeing_inode()) on the evict -> clear_inode() path with btree locks held, which was a rare deadlock but undoubtedly also one of the sources of the SRCU warnings. - new data structure for managing freelists in btree key cache This eliminates the btree key cache lock, and associated lock contention. User feedback is that this resolves the main source of the SRCU warnings we've been seeing - which means that on some of the big multithreaded workloads people are running the lock contention was really bad (threads piling up and causing O(n^2) wait times), if it was able to trigger a 10 second delay warning.
Szóval mindkettő a tesztelés alatt derült ki, és muszáj megcsinálni. Pont erre való a rc időszak, ekkor derülnek ki szélesebb körben is hibák a kiadott release candidate kernelekből. Ha egy rc kernelben lévő hibát nem lehet kis javítással megoldani, akkor csak nagy javítással lehet, az élet ilyen. Ezek nem új feature-ök, nem azért kerül be, mert a merge window után készült el, hanem mert tesztelés kimutatta, hogy nem várhat a javítás a 6.12-re.