On 0610T1150, Gary Jennejohn wrote: > On Tue, 8 Jun 2021 17:54:05 +0200 > Gary Jennejohn <gljennj...@gmail.com> wrote: > > [big snip]
[..] > So, I did ``git reset --hard 8dc96b74edb844bb621afeba38fe4af104b13120'', > which was the penultimate commit made by trasz to clear CCBs on the stack > after he committed 3394d4239b85b5577845d9e6de4e97b18d3dba58, the change > to allocate CCBs in UMA. > > Note that I only built the kernel and not world. > > I tried to reset to 3394d4239b85b5577845d9e6de4e97b18d3dba58 itself, > but without the following commits for CCBs on the stack the kernel > paniced during startup in AHCI. > > Anyway, this is the minimum set of changes relevant to the uma_ccbs > story and also results in a panic identical to the one listed above > when I set kern.cam.da.enable_uma_ccbs=1 and turn on the external USB > disk. > > So, Warner is probably right and at least the da_uma_ccbs commits > should be reverted until more research can be done on why the panic > happens. > > The ada_uma_ccbs commits do not cause any problems in my experience and > could probably be left in the kernel. Thank you, I'm working on a fix. Meanwhile - does the current code cause any problems with set kern.cam.da.enable_uma_ccbs set to 0? If it doesn't, it probably doesn't require backing off, since 0 is the default, and will keep being the default until bugs such as this one are fixed.
