BcacheFS for 6.17

Posted Aug 11, 2025 17:42 UTC (Mon) by koverstreet (✭ supporter ✭, #4296)
In reply to: BcacheFS for 6.17 by koverstreet
Parent article: Kernel prepatch 6.17-rc1

To expand upon the issue: you were telling multiple people, not just myself, "oh look, you didn't test with CONFIG_DEBUG_VM, go away".

I was explaining that this approach doesn't scale across subsystems, and there have been mm bugs that have been escaping into the wild because of it; the matrix of "configurations everyone has to test" has gotten too big, and not all issues are caught in testing.

I've wasted a ton of time chasing mm bugs because of this, Suren and I had to spend two days chasing down an mm bug not too long ago, and I still have an outstanding bug in compaction on my bug tracker.

Large folios made this worse, because now there are infinite loops that can be hit if the filesystem does things ever so slightly wrong; this affected actual users.

We all have to be kind and considerate, and part of this is being responsive to the issues people are facing when using your code. "You did it wrong, go away" isn't that.