So it a stack https://reviews.freebsd.org/D59151 and https://reviews.freebsd.org/D59152 are bugs that need to be backported
They cause a wedge/stall under certain conditions The next 2 53/54 are for all NVMe's, 54 trigger in controllers that advertise a non zero MAXCMD. Then 55 this is the one that touches every brand. It programs the Arbitration feature from Identify RAB on all non-quirked controllers. Both Apple controllers have QUIRK_IGNORE_RAB because they wedged under load. 56 are just Apple dequirkage for T1 drives... When i fixed the Apple T2 Nvme in D57087, it broke T1 (that used to work), so i had to patch it and depatch it. So if you want benchmark, you need to test between 15.1 and 16-Current with these patches. I observed the improvement across multiple setup, most consumer drive were ok. run 'sudo nvmecontrol identify nvme0' You will see something like 'Recommended Arb Burst: 2' <-- here 2 >From 0-7 (except 4 (i dont have 4)) i tested all. 6-7 are the top performers >with the new code. Anything over it is not tested but it already clamped. >(Also my tests were just copying a lot of files across the drive) So in short this stack is 2 bug fixes, 2 conformance commits and 2 fixes for apple nvme that don't respect the spec. Best. Abdelkader
